Adhesion of Organic Molecules on Silica Surfaces: A Density

Platform Technology Lab, Samsung Advanced Institute of Technology, 130 Samsung-ro, Suwon, Gyeonggi-do 443-803, Republic of Korea. J. Phys. Chem. C , 2...
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Adhesion of Organic Molecules on Silica Surfaces: A Density Functional Theory Study Mathew E. McKenzie, Sushmit Goyal, Sung Hoon Lee, Hyunhang Park, Elizabeth Savoy, Aravind Raghavan Rammohan, John C. Mauro, Hyunbin Kim, Kyoungmin Min, and Eunseog Cho J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.6b10394 • Publication Date (Web): 29 Nov 2016 Downloaded from http://pubs.acs.org on December 6, 2016

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Adhesion of Organic Molecules on Silica Surfaces: A Density Functional Theory Study *Mathew E. McKenzie1‡, Sushmit Goyal1, Sung Hoon Lee2, Hyun-Hang Park2, Elizabeth Savoy1, Aravind R. Rammohan1‡, John C. Mauro1, Hyunbin Kim2, Kyoungmin Min3, Eunseog Cho3 1

Science and Technology Division, Corning Incorporated, Corning, New York 14831, USA

2

Corning Technology Center Korea, Corning Precision Materials Co., Ltd., Asan,

Chungcheongnam-do 31454, Republic of Korea 3

Platform Technology Lab, Samsung Advanced Institute of Technology, 130 Samsung-ro,

Suwon, Gyeonggi-do, 443-803, Republic of Korea *Corresponding author

ABSTRACT Understanding the interface between organic and inorganic materials presents many challenges due to the complex chemistries involved. Modeling and experimental work have elucidated only a few facets of the physical and chemical nature of the adhesion between such surfaces. In this work, we use density functional theory to understand the adhesion between five different inorganic crystal surfaces (two dimensional silica, both sides of kaolinite, hydroxylated quartz, hydroxylated albite) with five different organic molecules (benzene, phenol, phthalimide, N-phenylmaleimide, diphenyl ether).

In the analysis, we explore the

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binding motifs that constitute parts of a polyimide monomer and examine their interactions with increasingly complex crystal surfaces. Comparing these systems, we elucidate the key factors (such as electrostatic interactions, hydrogen bond formation, and cation effects) that affect adhesion of organics on inorganic surfaces. It is found that the presence of cations and the availability of the oxygen species, in either the organic or inorganic layers, allows for increased hydrogen bonding. The most significant contribution to adhesion is from the rearrangement of surface electrostatic interactions. These factors can be used to optimize adhesion by decomposing both the organic and inorganic materials into the constituent interactions and help design improved interfacial properties.

1.0 Introduction Organic-inorganic adhesion is critical for numerous practical applications, such as protective coatings, adhesives, thin-film transistors, etc. Each organic and inorganic surface is unique and confers its own material attributes (e.g., Young’s modulus or coefficient of thermal expansion) to the interface. Inorganic glass substrates including high-purity fused silica, ion-exchanged aluminosilicate glass, glass-crystal composites, soda lime silicate, and borosilicate glasses are commercially available and are widely used in industry. Thermally stable organic polymers such as polyimide (e.g., Kapton, UPILEX) are often used in high-temperature applications such as flexible display substrates, protective coatings, and adhesives because of its excellent mechanical, thermal, and chemical-resistant properties1,2. Understanding the glass-polyimide interface is important particularly for manufacturing flexible display for television and hand held electronic devices. The properties of glass and polymers undergo changes during processing conditions and the unique interfacial characteristics could potentially introduce variability to

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both the process and the product attribute. Specifically, adhesion between polymer and glass can be influenced by the inorganic surface roughness3, surface and bulk composition4, density of hydroxylated groups5, zeta potential6, and physisorbed water layer7 all of which, in turn, could affect the overall functionality of the glass-polymer application. A few surface characterization experimental techniques8-12 such as atomic force microscopy with chemical force mapping (AFM-CFM) and temperature programmed desorption (TPD) have been able to probe the interaction of the inorganic surfaces with organic molecules. AFM-CFM is sensitive to the nature of the interface being probed since it uses an AFM tip coated with an organic molecule and measures the force required to interact with the surface. The unknown geometry of the tip with attached molecules makes the measured force difficult to interpret. TPD is a straightforward method to measure adhesion, since one heats the surface and measures the amount of absorbate release over a thermal cycle. Yet, TPD assumes the adsorption and desorption process is a completely reversible process. Furthermore, if there are multiple binding motifs, TPD is unable to distinguish different attachment sites, though by connecting to mass spectrometry and thermal gravimetric analysis one can probe the surface more quantitatively. These techniques are useful to answer questions like how receptive is a surface to a particular molecular type? How much energy is required to desorb a molecule? Or, how well can an adsorbate incorporate into the substrate? Using these methods one can probe the effective adhesion of organic molecules or inorganic surfaces. Complimentary to experiments, computational modeling is a powerful tool that can be used to study the adhesion behavior of organic molecules on the inorganic surfaces. Among the many tractable computational approaches for the organic-inorganic interfaces, molecular dynamics with classical atomistic force fields has been used to study a variety of inorganic glass systems13© 2016 Corning Incorporated. All Rights Reserved.

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and their properties, including chemical diffusivity, structure, and mechanical properties.

Similarly, this approach has been used to elucidate polymer attributes like packing ability and structure factors20-22, adsorption processes23,24, and rheological properties25-28. However, when combining the glass and polymers together in a molecular dynamics simulation, there is a deficiency in the available tools and parameters which do not allow the accurate modeling of the interfacial properties (e.g., adhesion). While there is some work that has been published on characterizing certain interfacial attributes of silica nanoparticles in a polyimide matrix29-31 only two previous works32,33 focus on characterizing the adhesion between glassy/crystalline silica and polyimide. In these previous studies, the adhesion between BPDA polymer chains and glassy silica32 is characterized using ReaxFF, and the adhesion of BPDA monomer on both glassy and crystalline silica with and without hydroxylation33 is investigated using the Interface potential34. While these two papers provide specific insights into the interactions at the nanometer scale, the chemical nature of each of these subunits and the role of specific atoms in mediating the adhesive properties have not yet been addressed in detail due to limitations of classical atomistic force fields. Goyal33 investigated monomer adhesion and began looking into some interesting aspects like differences in local oxygen density between the Kapton monomer and the BPDA monomer, which helps explain the larger adhesion observed with Kapton. However, it does not capture the effects of electronic structure of the chemical environment of these atoms and how they interact with the inorganic surface atoms in a concerted manner to either enhance or limit the overall adhesion of the monomer—and ultimately the polymer—onto the surface. To address such questions at this level, we need to use more detailed methods such as density functional theory (DFT) or ab initio molecular orbital theory.

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In the literature, DFT has been used to investigate different glassy systems containing low hundreds of atoms (< 400) to address problems such as the structural evolution of germanium melts35, embedded clusters in silica36, bioactivity mechanism of soda-lime phospho-silicate glasses37, interface of silicon surfaces with water38, densification of silica39, molten glass structures40 and nanocomposite materials for solar energy collection41. These studies used B3LYP42, PBE043, and PW9144 functionals that have shown good predictions for the structure, compositional changes and band gap. Using a similar set of functionals, DFT studies on polymers have included polyvinyl refractive optical properties45, entropy of mixing and phase transitions of homopolymers46, polyimides for fuel cells stability and reactivity47. However, the literature is very limited when it comes to the characterization of the organic-inorganic interfacial system. The closest references include carbon dioxide48, hydrogen49, or other small molecules50-52 reacting on metallic transition metal surfaces. Given the gap in understanding of the detailed interactions of a polyimide monomer’s interaction with silicate surfaces, we focus on addressing this specific interfacial system. Here, the focus is how the surface interactions with an organic molecule, or in other words, how accurate are the molecular simulations whose force fields were not optimized for these systems? The composite model of polymers and glass surface requires large systems to explore this question. A typical polyimide monomer, for example, BPDA 1,4,4-APB has around 60 atoms and a small inorganic surface has around 350 atoms, hence to consider the entire system would result in a fairly large system (>400 atoms) by DFT/ ab initio standards. On the other side of the interface, the glass requires a reasonably large system size, for example at the very least 300 (for its non-periodicity) making the interfacial system with the added polymer computationally expensive. To address the system size problem, we used two approaches to scale down the model © 2016 Corning Incorporated. All Rights Reserved.

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to access higher level quantum mechanical approaches to properly probe the interfacial interactions. To handle the polymer length, we propose an initial approach of dividing the monomer into constituent organic subunits/molecules and probe the interaction of each of these subunits with the inorganic surface. While this simplified approach can not address the physics of the polymer material on a surface; it should allow us to capture the unique interactions between the materials more accurately than classical approaches. The learnings from this model could then potentially be used to either perform a few select studies for a larger system or develop better parameters to then study the larger system with a classical force field. To further reduce the system size, we identify surrogate crystal structures like a two dimensional (2D) silica bilayer which has certain attributes of glassy silica and then systematically look at different crystalline variants (with compositions representative of industrial glasses) like kaolinite and hydroxylated albite where we investigate the effect of surface structure and composition (atomically smooth vs. more opened hydroxylated surface), compositional variation like role of Si, Al, Na and effect of hydroxylation of the surface in controlling the adhesion. By understanding the interactions between the five different inorganic surfaces with five different organic subunits (that constitute the BPDA 1,4,4 APB polyimide), we generate significant fundamental understanding of key factors that drives stickiness of inorganic surfaces to certain types of organic molecules. In our analysis, we will show a level of theory comparison for different DFT methods, explore an adhesion of single and double aromatic ring molecules across all glassy silica surfaces, a closer inspection of their adhesion to hydroxylated surfaces, and analysis of the overall trends of all subunits and surfaces. 2.0 Methods 2.1 Description of the inorganic surfaces © 2016 Corning Incorporated. All Rights Reserved.

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A glass surface has many attributes such as the degree of hydroxylation, density and types of cations, and type of hydroxylated species (e.g. Si vs. Al). To understand systematically the role of these different glass surfaces’ attributes on the binding of organic molecules, we construct a series of surfaces that start with the simplest two dimensional silica bilayer53 and gradually increase the complexity by hydroxylating and adding cations. The progression of simple to complex surfaces considered for this study is shown in Figure 1 where, following the left branch in the figure, the 2D silica bilayer is first translated into a full three dimensional (3D) silica structure, and then hydroxylation generates the hydroxylated quartz surface. With the introduction of sodium and aluminum, we obtain a hydroxylated albite surface. Similarly following the right branch in the figure and again starting with the 2D silica bilayer, we introduce a 3D silica structure along with the aluminum cation resulting in the kaolinite system. Kaolinite presents two different surfaces to the organic subunits, an aluminum and silica rich sides. To distinguish these sides, we will use the notation Al-kaolinite or Si-kaolinite to indicate the appropriate surface being studied. Kaolinite does have aluminols as part of its crystal structure. These hydroxyl units behave differently than the other surface hydroxyls (in hydroxylated albite and quartz) in this study because the kaolinite hydrogens are needed to charge compensate for the alumina. These kaolinite aluminols do have strong hydrogen bonding complexes with water54 and creates a well ordered water monolayer. Unlike the albite and quartz hydroxylated groups, the kaolinite hydrogens are unlikely to precipitate in surface reactions though can chelate metal ions55. For this reason, we are not considering kaolinite as a hydroxylated surface since these hydroxyls were not formed from water condensation reactions on the surface (like in albite or quartz). With the addition of sodium and modification of the hydroxyl groups of kaolinite, one obtains the hydroxylated albite surface. The dimensions of

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these surfaces are roughly 20 Å x 20 Å x 10 Å, containing ~180 atoms for all the systems. The surfaces are net neutral in charge (by end capping with hydrogen atoms) and are obtained from the American Mineralogist Crystal Structure Database56. The number densities of each elemental species is provided in Table 1. 2.2 Description of the organic molecules We focus on polyimides and specifically the BPDA 1,4,4-APB since this is a system which we have studied using classical methods in our earlier study33. A single monomer of BPDA 1,4,4APB has roughly 60 atoms. To study the adhesion of a single monomer onto the inorganic surface, the overall system would be greater than 300 atoms. These calculations are computationally expensive for the different levels of theory. To manage the computational cost while maintaining reasonable accuracy for interfacial interactions, we computationally decompose the polyimide monomer into five different subunits as shown below in Figure 2 as explained in the Introduction. The five subunits can be divided into two categories: one-aromatic ring molecules (benzene and phenol) and two-ringed molecules (phthalimide, Nphenylmaleimide, and diphenyl ether). It should be noted that when dividing the monomer to create subunits, we protonate the phenolate anion, creating phenol. This is done for three reasons: (1) to maintain a charge neutral system, (2) compare hydrogen bonding energies between various levels of theory (between phenol and benzene, having no hydrogen bond capability), and (3) phenol could have a role in polyimide chemistry (could be a solvent or incorporated as a copolymer for increased properties). The overall differences in the chemical nature of these subunits are listed below in the Figure 2, where it can be seen that all of the molecules besides benzene are either hydrogen bond (H-bond) donors or acceptors, suggesting that they can participate in hydrogen bond formation with the silicate surfaces. This is important © 2016 Corning Incorporated. All Rights Reserved.

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since the differences in the strength of the interactions between these are almost always directly related to their hydrogen bonding tendencies. Although the real polymer system would include many intertwined chains with many degrees of freedom and possible steric hindrances, this work illustrates the low energy binding configurations of monomer fragments that captures the critical non-bonded interactions that are important for adhesion. 2.3 Level of theory calibration and selection of computational approach We investigate both periodic and cluster systems to calibrate the optimum level of theory required for the simulation. Using the ab initio methods, we are restricted to working with a cluster model. On the other hand, DFT is used to study both cluster and periodic systems to ensure accuracy of the cluster model and of the DFT comparison to ab initio results. By grounding our cluster calculations with the ab initio MP257 method, we intrinsically expect to capture the van der Waals interaction more accurately and therefore better compare among all levels of theory. Additionally, we studied the DFT method of the Grimme correction58, DFT-D2, which is meant to capture the effect of van der Waals more accurately than with ordinary DFT58,59. Similar to our study, simple organic molecule adsorption on metal surfaces used DFTD2 and was found to overestimate the adhesion energy60,61. To alleviate the overestimation, one could scale the DFT-D to fit a series of ab initio calculated known metal-ion containing complexes. This is not a straight forward solution as one must investigate carefully the many electronic states and band gaps which would affect the dispersion energies. The proper treatment of DFT-D parameters of metal atoms at this point remains an open question. Due to these concerns, we do not attempt to optimize the DFT-D2 correction parameters. Initial Model Setup

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Ultimately, for the cluster calculations, one needs a good starting configuration using a periodic system to determine the important surface groups and their configuration to carve out the cluster model. First, we generate initial 100 configurations using a standalone script. This script applies rotations and translations to the organic subunits with respect to the surface. These configurations are used for geometry optimization in VASP62 using PBE44 with PAW63 and a planewave cutoff energy of 250 eV with a vacuum size of 30 Å. From these 100 different configurations, a certain fraction (typically 10%) was discarded due to unfavorable contacts with the surface. We identify the lowest energy configuration of each structure to create cluster system which is used for the level of theory calculations and other analysis. Cluster calculations Using the cluster configurations that were carved from the VASP periodic system, we use Gaussian64 and conduct another geometry optimization to ensure the proper energy surface and atomic configurations between these two methods. The Gaussian calculations used the Berny geometry optimization with the tight convergence criteria. The ab initio calculations were limited to single point energy calculations and geometry optimizations was not carried out. To establish the right level of theory for the study in this paper, we investigated two different DFT methods: PBE and B3PW91, with three different basis sets of increasing sizes: 6-31G*, 6311G*, 6-311++G(2d,2p). We also investigated one ab initio method, MP2 with the Dunning’s augmented correlation consistent basis set (aug-cc-pVTZ). The MP2 calculation used DFT double zeta set optimized geometries. The basis sets parameters and implementation of the method is implemented in the Gaussian software64. Periodic calculations © 2016 Corning Incorporated. All Rights Reserved.

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The DFT calculations use the PBE method with both the atomic orbital basis sets (e.g., 631G*) and using planewaves via the PAW method. The purpose of these is to ensure that the cluster calculations are representative of the periodic system. The actual comparison between these different levels of theory and choice of the computational method for the rest of the studies is presented in the Results and Discussion section. 2.4 Computational method for characterizing interaction between organic subunits and inorganic surfaces For calculating the adhesion of the organic subunit, we calculate the energy of the combined system (i.e., organic subunit in the lowest energy configuration on the surface) and subtract the total of the energy of the inorganic surface and the organic subunit in vacuum. This difference is what is reported as the adhesion energy for the rest of our study. 3.0 Results and Discussion 3.1 Analysis of level of theory calculations Table 2 shows the level of theory calculations for phenol and benzene on the 2D silica bilayer surface and the hydroxylated albite surface. The ab initio calculations using the MP2/aug-ccpVTZ are known to be more accurate compared to the other levels of theory65. Hence the DFT calculations that are comparable to the results from MP2 will be chosen as the preferred method for all the other calculations reported in this work. Note, all systems studied have medium-weak hydrogen bonding and DFT is known to have a small error associated with their adhesion energy per hydrogen bond of 1-2 kJ/mol66. © 2016 Corning Incorporated. All Rights Reserved.

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The ab initio calculations show that for both 2D silica bilayer and the hydroxylated albite surfaces, the adhesion energy of phenol is greater than that of benzene by ~11 kJ/mol. This difference occurs as the hydrogen bonding tendencies of phenol is higher than benzene which has only the delocalized pi electrons to contribute to non-bonded interactions. Another point to note is that the individual binding energies on hydroxylated albite for both subunits are stronger by ~6kJ/mol, suggesting that albite is a more adhesive surface for organic subunits compared to 2D silica. We will return to this point later in greater depth as we look at the different surfaces and subunits. Next, we examine the effect of the DFT-D2 Grimme correction for capturing the adhesion energy. Since this correction adds in van der Waals energies and this system’s adhesion comes from non-bonded energies, one would expect a good complementing technique. We see that this correction tends to systematically over predict a larger contribution from hydrogen bonding when compared to the ab initio method. Regardless of basis set size, the correction results in a similar over-prediction for the different basis set size calculations. The predicted difference between phenol and benzene via DFT-D2 ranges between -17 to -20 kJ/mol on 2D silica and has a slightly smaller difference on albite (i.e. -14 to -17 kJ/mol). The ab initio MP2 calculation for both surfaces shows phenol having a larger hydrogen bonding, as is expected, and albite once again shows itself as being more adhesive than 2D silica. Given that the estimated contribution of the hydrogen bonding is larger than what we observe from the ab initio simulations, we conclude that the Grimme correction tends to overestimate the hydrogen bonding for our systems; hence, we do not consider this method for the remainder of our calculations. When we look at the DFT cluster calculations using the PBE functional for different basis set sizes, we see that larger basis sets leads to a smaller contribution from hydrogen bonding, viz., © 2016 Corning Incorporated. All Rights Reserved.

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ranging from -7.9 kJ/mol for 6-31G* to -3.2 kJ/mol for the 6-311++G(2d,2p). This same trend is seen with the B3PW91 DFT calculations for the two different basis set sizes. Interestingly, the hydrogen bonding contributions are better captured by DFT using the smaller basis set sizes, e.g., 6-31G*. This reveals that the larger superposition errors using smaller basis sets can yield energies that are closer to the ab initio results compared to those from DFT calculations using larger basis sets65. This also emphasizes the need for performing a level of theory convergence study, as we have done, to choose the appropriate level of theory for the specific system under study. Based on this convergence study, we have selected the B3PW91/6-31G* cluster calculations to be the appropriate level for all further calculations. Furthermore, Table 2 shows the results using the periodic structures with DFT and shows that qualitatively, the trends are similar to what we observe with the cluster calculations. Careful partitioning of the cluster space (active realistic surface vs. exterior hydrogen bonded terminal ends) is required to ensure the appropriate adhesion configurations to mimic the periodic system67. 3.2 Differences in adhesive behavior of phenol and phthalimide on the five different inorganic surfaces In this section we compare two subunits (single ring phenol and double ring phthalimide) across all the different surfaces. From Figure 2 we recall that phenol has a hydroxyl group that can participate in hydrogen bond formation. The phthalimide has two carbonyl oxygen groups, which can again participate in hydrogen bond formation. The other structural difference to note is that phenol has one aromatic ring while phthalimide has one aromatic ring in conjunction with a five-membered ring containing nitrogen. The presence of nitrogen also contributes to the increased electronegativity which could promote further interactions. In Figure 3, we compare the adhesion of phenol and phthalimide onto the five different surfaces. © 2016 Corning Incorporated. All Rights Reserved.

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Given these structural differences, we see that the adhesion of both of these molecules increases when progressing from 2D silica to hydroxylated albite. For phenol, moving from the 2D silica to Si kaolinite surface the adhesion energy increases only slightly from -11.6 kJ/mol to -11.7 kJ/mol. Although the Si kaolinite surface structure does have an aluminol embedded, its surface is very similar to 2D silica including the adhered configurations (See Si Kaolinite and 2D silica rows in Fig 3). When we consider the interaction between phenol and the Al kaolinite surface, the adhesion increases to -12.1 kJ/mol. Phenol adhered structures are much more planar on the Al kaolinite surface than on the Si kaolinite, as shown in their corresponding rows of Figure 3. The phenol distance from the surface is similar between both Si and Al kaolinite (since this measurement is taken from the plane of the Al (for Al kaolinite) or Si (for Si kaolinite)). The hydroxyl hydrogens in kaolinite (Figure 3) are there for charge compensation of the alumina layer. Due to this charge compensation and confined Al geometry, upon adhesion these hydrogens are not able to rotate as much as a hydroxyl group found in other hydroxylated surfaces (e.g., hydroxylated quartz). On hydroxylated quartz (Figure 3), we see that the H-bond distance of the phenol is shorter than on Al kaolinite with an angle of 35o vs. 15o (more inclined and less planar), clearly suggesting that the increased adhesion (by 3.2 kJ/mol compared to Al kaolinite) is being driven by the enhanced hydrogen bonding between both the surface hydroxyl groups and that of phenol. Finally on hydroxylated albite, which presents Si/Al/Na/O and OH groups on the surface, we see that the adhesion increases by 8.7 kJ/mol with respect to 2D silica. Furthermore, when we compare the adhesion with respect to Si kaolinite and Al kaolinite, we see an increase of 7-8 kJ/mol. Comparing hydroxylated quartz with hydroxylated albite, we see an increase of ~5 kJ/mol. We also observe that the distance of phenol from the inorganic surface is greatest for the © 2016 Corning Incorporated. All Rights Reserved.

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hydroxylated albite substrate; however, the hydroxylated albite surface has inherent roughness and hence the distance is less well defined compared to the other smooth surfaces likes 2D silica. The orientation of these organic molecules are also less planar on hydroxylated albite, but now two hydrogen bonds are observed, one being mediated by the surface hydroxyl groups and the other interestingly by the sodium atoms. This allows us to conclude that the presence of sodium atoms on the surface enhances the adhesion by close to 5 kJ/mol and is largely due to the electrostatic nature of the interaction between the positively charged cation (Na) and the negatively charged hydroxyl group (OH) on phenol. The presence of surface sodium also brings the surface hydroxyl groups closer to the sodium which potentially strengthens the hydrogen bonding between these hydroxyl groups and that on phenol. Turning our attention to the adhesion of phthalimide, we see some similarities in the behavior with phenol and some interesting differences. As with phenol, the adhesion energy of phthalimide progressively increases from 2D silica to hydroxylated albite. For both the kaolinite surfaces, these two subunits adhere in a more planar configuration due to the same two reasons: (1) Si kaolinite is atomically smooth like 2D silica and (2) the rigid non-interacting aluminols prevent any direct hydrogen bonding. However, the degree of adhesion of phthalimide onto Si kaolinite and Al kaolinite is weaker compared to phenol on the same two surfaces. We attribute this difference to the fact that phthalimide is a larger molecule containing two rings, which enhances its rigidity and steric hindrances, especially for less planar surfaces. Notice the difference between phenol and phthalimide on the hydroxylated quartz surface (Figure 3). Here, the adhesion energy is similar (phenol -15.3 kJ/mol vs phthalimide -16.3 kJ/mol) but the angle which the subunit makes with respect to the surface is very different (35o for phenol vs. 16o for phthalimide). This difference in orientation is driven by the fact that phthalimide makes three © 2016 Corning Incorporated. All Rights Reserved.

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hydrogen bonding contacts with the surface while phenol makes only one. These additional bonds restrict the orientation on the surface increasing the planarity of the molecule. When we examine the behavior of phthalimide on hydroxylated quartz and hydroxylated albite, we see that phthalimide finds these two surfaces highly adhesive (Figure 3, bottom two rows). On hydroxylated quartz, the presence of the surface hydroxyl groups clearly mediates at least 3 hydrogen bonds resulting in a much flatter orientation of the phthalimide with respect to the surface. This change in orientation clearly allows more of the phthalimide groups to interact with the surface, which results in an increase of adhesion energy by 1 kJ/mol compared to phenol. On hydroxylated albite, the presence of the positively charged cation appears to increase the overall electrostatic interactions between the two negatively charged carbonyl oxygens on phthalimide and the electronegative nitrogen atom, and contribute to an 8 kJ/mol increase in the adhesion. This is greater than the 5 kJ/mol increase we saw with phenol’s adhesion moving from hydroxylated quartz to hydroxylated albite. These two comparisons bring out some of the fundamentals of adhesion of organic molecules onto surface. There is a balancing act between the polar groups’ non-bonded interactions and the subunit’s planarity/rigidity68 that drives how close the adhered molecule can approach the surface. From the surface perspective, composition changes can alters both structure and electrostatic environment as seen from both the Si kaolinite and the Al kaolinite surfaces. Understanding these adhered configurations with respect to surface and subunit characteristics, one could possibly formulate an optimized adhesive material by manipulating either the inorganic surface attributes like type of cation or tailoring the organic moieties like presence/absence of ring like structure, nature of chemical groups, size etc. through computeraided material design techniques. © 2016 Corning Incorporated. All Rights Reserved.

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3.3 Differences in adhesive behavior of the five different organic molecules on hydroxylated inorganic surfaces Behavior of single ringed organic molecules When we compare the behavior of benzene and phenol adhesion to the two hydroxylated surfaces, it is to be expected that phenol binds more strongly on both these surfaces and further overall adhesion to hydroxylated albite is tighter. This is in line with the analysis presented in the earlier section where the presence of surface hydroxyl groups, sodium cations, and aluminum were all involved with enhancing the adhesion energy of hydroxylated albite. The increase in adhesion energy between phenol and benzene is -12.2 kJ/mol on hydroxylated quartz while on hydroxylated albite it is -12.5 kJ/mol. The overall adhesion of both benzene and phenol individually increased on hydroxylated albite while the net difference in adhesion was comparable to that observed on hydroxylated quartz. Behavior of double ringed organic molecules With respect to the double-ringed structures, we explained earlier that phthalimide has three key atoms that play a role in enhancing the adhesion: the two carbonyl oxygen atoms and the nitrogen atom. When we compare the N-phenylmaleimide structure with the phthalimide structure, we note that they both contain these two carbonyl oxygen atoms and the nitrogen atom. However, N-phenylmaleimide’s nitrogen serves as the linker atom between the 5 membered ring structure(forming tertiary amine) and the phenyl group while in phthalimide the nitrogen atom is freely available (forming secondary amine) and is bonded to a hydrogen atom. This small but subtle change from a tertiary to secondary amine is likely to result in differences in the adhesive behavior because the nitrogen can access the aromatic ring’s delocalized pi cloud (lowering © 2016 Corning Incorporated. All Rights Reserved.

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nitrogen’s affinity to any surface group) and this is a planar sp2 imide nitrogen69. Furthermore, the anti-bonding orbitals of the carbonyl oxygens next to the nitrogen can conflict with the delocalized electron cloud resulting in an inherent strain in the molecule forcing the aromatic ring to be at a certain angle with respect to the five membered ring. This would therefore rule out the possibility of an overall planar configuration of the N-phenylmaleimide on the substrate. Due to the combination of the tighter linkage between the two rings via the nitrogen and limited planar conformations, we find that N-phenylmaleimide has weaker adhesion than phthalimide (see Figure 4, 20-30% weaker depending on the surface). Diphenyl ether has two aromatic rings that are linked by the ether bond through the oxygen atom. This oxygen has reasonable access to the delocalized pi electrons from either of the aromatic rings, and the ether bond is known to be less rigid70 than the nitrogen-carbon bond seen in N-phenylmaleimide. This is likely to confer overall a slightly larger flexibility for the two aromatic rings that constitute the ether, which could potentially handle steric hindrances a bit more effectively. In light of this when we look at these three two-ringed structures interacting with the two hydroxylated surfaces in Figure 4, we see that phthalimide has the highest adhesion energy in line with our expectation due to the presence of the two carbonyl oxygens and the freely available nitrogen atom. Keeping with our earlier trend the adhesion onto hydroxylated albite is larger by almost -12kJ/mol, due to the combination of Al and Na. When we look at Nphenylmaleimide and diphenyl ether, one might have expected that the N-phenylmaleimide should have had stronger adhesion given that functionally it has the two carbonyl oxygens and the nitrogen atom. We however observe that the adhesion energy is comparable to that of diphenyl ether and perhaps just a bit higher (-0.8 kJ/mol) on hydroxylated quartz while actually being a bit lower on the albite surface (-0.5 kJ/mol). These results in light of the earlier analysis © 2016 Corning Incorporated. All Rights Reserved.

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reinforces that the electronegativity of the N-phenylmaleimide while helping adhesion is perhaps being limited by its intrinsic rigidity or limited conformational flexibility. The chemical nature of the organic molecules play a large role in modulating the adhesion, specifically, certain locations can alter the chemical environment significantly. For instance, Nphenylmaleimide has the same three chemical groups as phthalimide, but changes in rigidity and limited availability of all the atoms to participate in the surface interaction limits the overall adhesion. In addition, the size of molecules affects adhesion and smaller molecules have lower steric hindrances and hence greater access to the surface, but the presence of certain functional groups like the carbonyl oxygens and nitrogens can enable better interactions with surface groups which could offset the steric hindrances with heighten adhesive interactions. In other words, larger molecules may experience larger steric hindrance but can adhere more tightly due to the increased interactions of the additional functional groups. These trends help in explaining the fundamental nature of who and what drives the interactions and can be effectively leveraged to modulate the surface interactions. 3.4 Reconstituting the polymide monomer from its subunits There is a large gap to span from a collection of individual organic subunits to a monomer and eventually to a polymer film. For instance, with these five subunits, one can create many different polymers including isomers of the same polymer. A polymer has many degrees of freedom and the most, this study has sampled has been three molecules each with one rotatable bond. With this in mind, can we perform a first order check on the adhesion? The BPDA or Kapton monomer can be constructed multiple ways but the focus here is on qualitative comparison between various polyimides. We made a couple assumptions to combine subunit

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adhesion energies for the monomer adhesion. Instead of trying the many different combinations of subunits to create a monomer, we choose to first fit the largest rotatable subunits first. The larger subunits have more interacting sites and flexibility than the smaller subunits; therefore would be a better comparison to the monomer. In our earlier study33, we predict the adhesion of BPDA and Kapton monomers on hydroxylated and non-hydroxylated quartz surfaces using molecular dynamics. To compare their predictions with this work we decompose their monomers according to Figure 5. In this decomposing the Kapton and BPDA monomers, we do not use any phenol values but that may not be the case for all polyimides. According to these decompositions of the monomers, we find Kapton and BPDA monomer adhesion energies would be -40 kJ/mol and -48 kJ/mol, respectively, using the subunit interaction energies from Table 3 on hydroxylated quartz. Noting that the Kapton is roughly 60% the size of BPDA, the normalized surface adhesion for BPDA would be -48/A kJ/mol (or 48 kJ/mol) and for Kapton -40/(0.6A) kJ/mol (or -65 kJ/mol), where A is the projected area of the BPDA molecule. From Goyal et al.33, the per surface area adhesion of these two monomers on hydroxylated quartz to be 0.142 kJ/m2 and 0.11 kJ/m2 for Kapton and BPDA respectively. Comparing the Kapton to BPDA adhesive ratio, from this work using DFT we obtain 1.35 while this ratio in Goyal et al. is 1.29. Although one study is DFT on a cluster system and the other is periodic 2D slab using a classical force field, this agreement in the predicted ratios is quite encouraging. The actual adhesion values understandably are quite different given that DFT looks at individual subunits while classical looks at the entire monomer along with the dynamics. 4.0 Summary and Conclusions

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The overall result summary is shown in Table 3 and Figure 6. Benzene is found to have the weakest adhesion which is understandable given that it is an aromatic molecule with very little to no groups that can have non-bonded interactions with our inorganic surface either through hydrogen bonding or electrostatic interactions. Having an easily rotatable bond, phenol has relatively strong adhesion on all surfaces and does follow the progressive trend from 2D silica to hydroxylated albite. Being able to both hydrogen bond donate and accept is a key attribute to increase adhesion on hydroxylated surfaces as seen by phthalimide. From the most complex in compositional space and being hydroxylated, albite was the most adhesive surface. To summarize, we observe four points that mediate interactions at the organic-inorganic interface; 1.

Hydrogen bond formation is a critical factor in mediating the non-bonded interactions.

2.

Electrostatics can play a significant role as seen from the role of sodium in the presence

of negatively charged groups like hydroxyl. 3.

Changes in surface composition can alter both structure and electrostatic environment as

seen from both the kaolinite surfaces which hydrogen bond accepting subunits are favored to bind on the alumina side. 4.

Rigidity of the organic subunit can enhance the adhesive contact by lowering the

conformational degrees of freedom which allows for additional stability with respect to the surface interactions. For instance, N-phenylmaleimide has the same three groups as phthalimide but changes in rigidity limits the availability for all the atoms to participate in the surface interaction thereby limiting the overall adhesion.

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Lastly, our analysis shows good agreement between classical and DFT-based reconstituted monomer adhesion ratios of Kapton to BPDA 1,4,4-APB, which also gives us some confidence in the classical Interface force field [34]. Our future work will involve using DFT to characterize the torsional potentials for the nitrogen groups in the Interface potential. We believe this can potentially help better characterize the stacking observed with these kinds of polyimides.

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Figure 1. Progression of surfaces, simple (2D silica) to complex (hydroxylated albite) used in this study to understand the role of surface composition. The coloring scheme that will be used for all figures is as follows: sodium (blue spheres), silicon (yellow), aluminum (pink), oxygen (red), and hydrogen (white).

Figure 2. Representation of polyimide monomer as a combination of 5 key smaller organic subunits to enable computations with a higher level of theory. Yellow atoms indicate the repeat bridge. Coloring scheme is oxygen (red), carbon (grey), nitrogen (blue), and hydrogen (white). Same atom coloring scheme is used throughout the paper.

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Figure 3. The bound configurations of phenol and phthalimide on all surfaces. The Bonds attribute denotes distance, shown as black lines, of the electrostatic bonding (e.g., hydrogen bond) from the subunit to a particular element on the surface (in parentheses).

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Figure 4. Comparison of all subunits on the hydroxylated quartz and albite surfaces. The Bonds attribute denotes distance, shown as black lines, of the electrostatic bonding (e.g., hydrogen bond) from the subunit to a particular element on the surface (in parenthesis).

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Figure 5. Reconstituting organic subunits from DFT into polyimide monomer for Kapton and BPDA 1,4,4-APB. Yellow circles denote the repeat areas.

Figure 6. Plot of Table 3 showing the combined trends of hydroxylation, aluminol addition, and cation across all surfaces and subunits. Arrows indicate the adhesion trends going from 2D silica to kaolinite (blue arrow), to hydroxylated quartz (red arrow), then to hydroxylated albite (green arrow). TABLES. © 2016 Corning Incorporated. All Rights Reserved.

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Surface

Silanol Hydroxyl

Aluminol Hydroxyl

Sodium

Aluminum

Silicon

2D Silica

0

0

0

0

17.5

Kaolinite

0

16.0

0

8.0

8.0

Hydroxylated Quartz

5.1

0

0

0

13.0

Hydroxylated Albite

3.0

2.0

2.0

3.0

7.3

Table 1. Surface number densities per nm2 of each cluster.

Method

With DFT-D2

System Setup Software

/

2D silica

Hydroxylated albite

Phenol

Benzene

Eadhesion (kJ/mol)

Eadhesion (kJ/mol)

∆ (kJ/mol)

Phenol

Benzene

Eadhesion (kJ/mol)

Eadhesion (kJ/mol)

∆ (kJ/mol)

MP2/aug-ccpVTZ

N/A

Cluster/Gaussian

-12.9

-2.2

-10.7

-18.8

-7.8

-11.0

B3PW91/631G*

No

Cluster/Gaussian

-11.6

-2.7

-8.9

-20.3

-8.6

-11.7

B3PW91/6311G*

No

Cluster/Gaussian

-4.9

-0.9

-4

-10.3

-3.1

-7.2

PBE/6-31G*

No

Cluster/Gaussian

-11.3

-3.4

-7.9

-19.9

-8.5

-11.4

PBE/6-311G*

No

Cluster/Gaussian

-5.1

-1.1

-4

-9.1

-2.7

-6.4

PBE/6311++G(2d,2p)

No

Cluster/Gaussian

-4.1

-0.9

-3.2

-7.3

-2.2

-5.1

PBE/6-31G*

Yes

Cluster/Gaussian

-29.3

-9.6

-19.7

-33.5

-18.4

-15.1

PBE/6-311G*

Yes

Cluster/Gaussian

-25.4

-7.6

-17.8

-32.4

-17.8

-14.6

PBE/6311++G(2d,2p)

Yes

Cluster/Gaussian

-24.4

-6.1

-18.3

-31.5

-17.1

-14.4

PBE/6-31G*

No

Periodic/Gaussian

-9.5

-2.4

-7.1

-17.5

-8

-9.5

PBE/6-31G*

Yes

Periodic/Gaussian

-24.5

-7.8

-16.7

-30.4

-13

-17.4

PBE/PAW

No

Periodic/VASP

-0.6

-0.5

-0.1

-2.3

-1.7

-0.6

PBE/PAW

Yes

Periodic/VASP

-31.5

-17.1

-14.4

-34.5

-20.1

-14.4

Table 2. Level of theory examination of phenol and benzene on the 2D silica and hydroxylated albite surface.

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2D silica

Si kaolinite

Al kaolinite

Hydroxylated quartz

Hydroxylated albite

Benzene

-2.7

-2.8

-3.0

-3.1

-7.8

Phenol

-11.6

-11.7

-12.1

-15.3

-20.3

Phthalimide

-4.7

-5.6

-12.3

-16.3

-28.2

N-phenylmaleimide

-2.5

-3.6

-8.4

-11.3

-23.7

Diphenyl ether

-2.3

-2.3

-6.3

-10.5

-24.2

Table 3. Overall B3PW91/6-31G* adhesion energies (kJ/mol) of all subunits on all surfaces.

AUTHOR INFORMATION Corresponding Author *Mathew E. McKenzie. Email: [email protected]. Phone: 16079741494. Author Contributions ‡These authors contributed equally to this work. Notes The authors declare no competing financial interest. ACKNOWLEDGMENT We would like to thank Dr. James Rustad and Mr. Henry Herbol for their insightful comments and advice. Authors would also like to thank Corning Incorporated, Samsung, Sam Zoubi, Gautam Meda and J. Shin for supporting this work. REFERENCES (1) Escott, R.; Harris, F. W.; Hergenrother, P. M.; Makino, D.; Satou, H.; Sroog, C. E.; St. Clair, T. L.; Stenzenberger, H.; Suzuki, H.; Takekoshi, T.; et. al., In Polyimides;

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Stenzenberger, H. D., Hergenrother, P. M., Eds.; Springer Netherlands, 1990, p. 297. (2) Liaw, D.J.; Wang, K.L.; Huang, Y. C.; Lee, K. R.; Lai, J. Y.; Ha, C. S. Advanced polyimide materials: syntheses, physical properties and applications. Prog. Polym. Sci. 2012, 37, 907-974. (3) Peterson, A. M.; Jensen, R. E.; Palmese, G. R. Thermoreversible and remendable glass–polymer interface for fiber-reinforced composites. Composites Science and Technology. 2011, 71, 586-592. (4) Gellert, E. P.; Turley, D. M. Seawater immersion ageing of glass-fibre reinforced polymer laminates for marine applications. Composites Part A: Applied Science and Manufacturing.1999, 30, 1259-1265. (5) Holbery, J.; Houston, D. Natural-fiber-reinforced polymer composites in automotive applications. JOM. 2006, 58, 80-86. (6) Klee, D.; Hocker, H. Polymers for biomedical applications: improvement of the interface compatibility. In Biomedical Application Polymers Blends. 1999; Eastmond, G. C.; Hocker, H., Klee, D., Eds.; Vol. 149, 1-57. (7) Choi, M.; Kim, Y.; Ha, C. S. Polymers for flexible displays: from material selection to device applications. Prog. Polym. Sci. 2008, 33, 581-630. (8) Juhl, K. M.; Bovet, N.; Hassenkam, T.; Dideriksen, K.; Pedersen, C. S.; Jensen, C. M.; Okhrimenko, D. V.; Stipp, S. L. Change in organic molecule adhesion on α

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alumina (sapphire) with change in NaCl and CaCl2 solution salinity. Langmuir, 2014, 30, 8741-8750. (9) Chaudhury, M. K.; Gentle, T. M.; Plueddemann, E. P. Adhesion mechanism of polyvinyl chloride to silane primed metal surfaces. J. Adhesion Sci. Tech., 1987, 1, 29-38. (10) Lee, K.W.; McCarthy, T.J. Synthesis of a polymer surface containing covalently attached triethoxysilane functionality: adhesion to glass. Macromolecules, 1988, 21, 3353-3356. (11) Zhang, W.; Wang, Y.; Shen, Y.; Xie, M.; Guo, X. Mesoporous zinc aluminate (ZnAl2O4) nanocrystal: synthesis, structural characterization and catalytic performance towards phenol hydroxylation. Microporous and Mesoporous Mater., 2016, 226, 278-283. (12) Schaut, R. A. The effect of boron oxide on the composition, structure, and adsorptivity of glass surfaces. Ph.D. Thesis. Penn State, May 2008. (13) Gruenhut, S.; Amini, M.; Macfarlane, D. R.; Meakin, P. Molecular dynamics glass simulation and equilibration techniques. Molecular Simulation, 1997, 19, 139-160. (14) Yang, Z., Wang, B. and Cormack, A. N. The local structure of Fe in Li(Al, Fe)Si2O6 glasses from molecular dynamics simulations. J. Non-Cryst. Solids, 2016, 444, 1622.

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(15) Priezjev, N. Reversible plastic events during oscillatory deformation of amorphous solids. Phys. Rev. E: Stat., Nonlinear, Soft Matter Phys., 2016, 93, 013001. (16) Luo, J.; Vargheese, K. D.; Tandia, A.; Hu, G.; Mauro, J. C. Crack nucleation criterion and its application to impact indentation in glasses. Science Reports, 2016, 6, 23720. (17) Zhao, W.; Cheng, J. L.; Feng, S. D.; Li, G.; Liu, R. P. Intrinsic correlation between elastic modulus and atomic bond stiffness in metallic glasses. Mater. Lett., 2016, 175, 227-230. (18) Mantisi, B.; Bauchy, M.; Micoulaut, M. Cycling through the glass transition: evidence for reversibility windows and dynamic anomalies. Phys. Rev. B: Condens. Matter Mater. Phys., 2015, 92, 134201/1-134201/11. (19) Deb Nath, S. K. Study of the effect of sizes on the structural properties of SiO2 glass by molecular dynamics simulations. J. Non-Crys. Solids, 2013, 376, 50-60. (20) Sliozberg, Y. R.; Kroger, M.; Chantawansri, T. L. Fast equilibration protocol for million atom systems of highly entangled linear polyethylene chains. J. Chem. Phys., 2016, 144, 154901/1-154901/12. (21) Jung, I. S.; Lee, Y. J.; Jeong, D.; Graf, R.; Choi, T. L.; Son, W. J.; Bulliard, X.; Spiess, H. W. Conformational analysis of oxygen-induced higher ordered structure of a,b-alternating poly(arylene vinylene) copolymers by solid-state NMR and molecular dynamics simulations. Macromolecules, 2016, 49, 3061-3069.

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(22) Aoyagi, T. Computational modeling of polymer with hydrogen bonds. Polymer, 2015, 64, 91-93. (23) Mashio, T.; Ohma, A.; Tokumasu, T. Molecular dynamics study of ionomer adsorption at a carbon surface in catalyst ink. Electrochim. Acta, 2016, 202, 14-23. (24) Shoravi, S.; Olsson, G. D.; Karlsson, B. C.; Bexhorn, F.; Abghoui, Y.; Hussain, J.; Wiklander, J. G.; Nicholls, I. A. In silico screening of molecular imprinting prepolymerization systems: oseltamivir selective polymers through full-system molecular dynamics-based studies. Org. Biomol. Chem., 2016, 14, 4210-4219. (25) Kang, J.; Kim, K.; Kim, K. Molecular dynamics study on the effects of stamp shape, adhesive energy, and temperature on the nanoimprint lithography process. Appl. Surf. Sci., 2010, 257, 1562-1572. (26) Sirk, T. W.; Karim, M.; Lenhart, J. L.; Andzelm, J. W.; Khare, R. Bi-modal polymer networks: Viscoelasticity and mechanics from molecular dynamics simulation. Polymer, 2016, 90, 178-186. (27). Sablic, J., Praprotnik, M. and Delgado-Buscalioni, R. Open boundary molecular dynamics of sheared star-polymer melts. Soft Matter, 2016, 12, 2416-2439. (28) Jabbarzadeh, A.; Tanner, R. I. Molecular dynamics simulation and its application to nano-rheology. Rheology Rev., 2006, 165-216. (29) Marotzke, A.; Hampe, C. The energy release rate of the fiber/polymer matrix interface: measurement. J. Reinforced Plastics and Composites, 1997, 16, 341-352.

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(30) Pizzi, A. and Mittal, K. L. Handbook of adhesive technology. Marcel Dekker Inc.: New York, 2003. (31) Cheng, I. C. Overview of Flexible Electronics Technology. In Flexible electronics: materials and application. Wong, W. S., Salleo, A., Eds.; Springer; New York, 2009. Vol. 11. (32) Min, K.; Kim, Y.; Goyal, S.; Lee, S. H.; McKenzie, M.; Park H.; Savoy, E. S.; Rammohan, A. R.; Mauro, J. C.; Kim, H.; Chae, K.; et. al. Interfacial adhesion behavior of polyimides on silica glass: a molecular dynamics study. Polymer, 2016, 98, 1-10. (33) Goyal, S.; Park, H. H.; Lee, S. H.; Savoy, E.; McKenzie, M. E.; Rammohan, A. R.; Mauro, J. C.; Kim, H.; Min, K.; Cho, E. Characterizing the fundamental adhesion of polyimide monomers on crystalline and glassy silica surfaces: a molecular dynamic study. J. Phys. Chem. C. [Online early access]. DOI: 10.1021/acs.jpcc.6b08081. Published Online: Sept 12, 2016. http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b08081 (accessed Sept 12, 2016). (34) Lin, T. and Heinz, H. Accurate force field parameters and pH resolved surface models for Hydroxyapatite to understand structure, mechanics, hydration, and biological interfaces. J. Phys. Chem. C, 2016, 120, 4975-4992. (35) Bouzid, A.; Le Roux, S.; Boero M.; Massobrio, C. Origin of structural analogies and differences between the atomic structures of GeSe4 and GeS4 glasses: A first principles study. J. Chem. Phys., 2015, 143, 034504.

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(36) Du, J.; Kroll, P. Electronic structure and interfacial properties of Ge nanoclusters embedded in amorphous silica. J. Non-Cryst. Solids, 2010, 356, 2448-2453. (37) Berardo, E.; Pedone, A.; Ugliengo, P.; Corno, M. DFT modeling of 45S5 and 77S soda-lime phospho-silicate glass. Langmuir, 2013, 29, 5749-5759. (38) Pham, T. A.; Lee, D.; Schwegler, E.; Galli, G. Interfacial effects on the band edges of functionalized Si surfaces in liquid water. J. Am. Chem. Soc., 2014, 136, 1707117077. (39) Izvekov, S.; Rice, B. M. Mechanism of densification in silica glass under pressure as revealed by a bottom-up pairwise effective interaction model. J. Chem. Phys., 2012, 136, 134508. (40) Ohkubo, T.; Tsuchida, E.; Takahashi, T.; Iwadate, Y. Ab initio molecular dynamics simulations and GIPAW NMR calculations of a lithium borate glass melt. J. Phys. Chem. B, 2016, 120, 3582-3590. (41) Wippermann, S.; Voros, M.; Gali, A.; Gygi, F.; Zimanyi, G. T.; Galli, G. Solar nanocomposites with complementary charge extraction pathways. Phys. Rev. Lett., 2014, 112, 106801. (42) Becke, A. D. Density-functional thermochemistry. III. The role of exact exchange. J. Chem. Phys., 1993, 98, 5648. (43) Adamo, C.; Barone, V. Toward reliable density functional methods without adjustable parameters: the PBE0 model. J. Chem. Phys., 1999, 110, 6158.

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(44) Perdew, J. P.; Wang, Y. Accurate and simple analytic representation of the electrongas correlation energy. Phys. Rev. B., 1992, 45, 13244-13249. (45) Yu, X., Yi, B. and Wang, X. Prediction of refractive index of vinyl polymers by using density functional theory. J. Comp. Chem., 2007, 28, 2336-2341. (46) McMullen, W. E.; Freed, K. F. A density functional theory of polymer phase transitions and interfaces. J. Chem. Phys., 1990, 92, 1413-26. (47) Lopez-Chavez, E.; Pena-Castaneda, Y. A., de la Portilla-Maldonado, L. C., GuzmanPantoja, J.; Martinez-Magadan, J. M.; Oviedo-Roa, R.; de Landa Castillo-Alvarado, F.; Cruz-Torres, A. Role of sulfonation in the stability, reactivity, and selectivity. J. Mol. Model, 2014, 20, 2325. (48) Cui, C.; Han, J.; Zhu, X.; Liu, X.; Wang, H.; Mei, D.; Ge, Q. Promotional effect of surface hydroxyls on electrochemical reduction of CO2 over SnOx/Sn electrode. J. Catal. [Online early access] DOI: 10.1016/j.jcat.2015.12.001. Published Online: Jan 16, 2016. http://dx.doi.org/10.1016/j.jcat.2015.12.001 (accessed Aug 1, 2016). (49) Lahmer, M. A. Hydrogen sensing properties of the ZnO(0001) surface enhanced by Be doping: a first principles study. Sens. Actuators, B, 2015, 221, 906-913. (50) Muhich, C. L.; Qui, J.; Holder, A. M.; Wu, Y. C.; Weimer, A. W.; Wei, W. D.; McElwee-White, L., Musgrave C. B. Solvent control of surface plasmon-mediated chemical deposition of Au nanoparticles from alkylgold phosphine complexes. ACS Appl. Mater. Interfaces, 2015, 7, 13384-13394.

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(51) Gleizer, A.; Peralta, G.; Kermode, J. R.; De Vita, A.; Sherman, D. Dissociative chemisorption of O2 inducing stress corrosion cracking in silicon crystals. Phys. Rev. Lett., 2014, 112, 115501. (52) Ren, J.; Zhou, G.F.; Guo, Z. C.; Zhang, W. Density functional theory study on the surface reaction mechanism of atomic layer deposited Ta2O5 on Si(100) surfaces. Chemical Journal of Chinese Universities, 2009, 30, 2279-2283. (53) Bjorkman, T.; Kurasch, S.; Lehtinen, O.; Kotakoski, J.; Yazyav, O. V.; Srivastava, A.; Skakalova, V.; Smet, J. H.; Kaiser, U.; Krasheninnikov, A. V. Defects in bilayer silica and graphene: common trends in diverse hexagonal two-dimensional systems. Scientific Reports, 2013, 3, No. 3482. (54) Tunega, D.; Gerzabek, M. H.; Lischka, H. Ab initio molecular dynamics study of monomolecular water layer on octaherdal and tetrahedral kaolinite surfaces. J. Phys. Chem. B., 2004, 108, 5930-5936. (55) Ma, C.; Eggleton, R. A. Cation exchange capacity of kaolinite. Clays and Clay Minerals, 1999, 47, 174-180. (56) Downs, R. T.; Hall-Wallace, M. The American Mineralogist Crystal Structure Database. American Mineralogist, 2003, 88, 247-250. (57) Moller, C.; Plesset, M. S. Note on an approximation treatment for many-electron systems. Phys. Rev., 1934, 46, 618-622.

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(58) Grimme, S. Semiempirical GGA-type density functional constructed with a longrange dispersion correction. J. Comp. Chem., 2006, 27, 1787-1799. (59) Grimme, S. Semiempirical hybrid density functional with perturbative second-order correlation. J. Chem. Phys., 2006, 124, 034108. (60) Tonigold, K.; Grob, A. Adsorption of small aromatic molecules on the (111) surfaces of noble metals: a density functional theory study with semiempirical corrections for dispersion effects. J. Chem. Phys., 2010, 132, 224701. (61) Andersson, M.P. Density functional theory with modified dispersion correction for metals applied to self-assembled monolayers of thiols on Au(111). J. Theor. Chem., 2013, 2013, 327839. (62) Kresse, G.; Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B, 1993, 47, 558. (63) Blochl, P. E. Projector augmented-wave method. Phys. Rev. B, 1994, 50, 17953. (64) Frisch, M. J., Gaussian09 Revision E.01. Wallingford, CT : Gaussian, Inc., 2009. (65) Cramer, C. J. Essentials of Computational Chemistry. Wiley: New York, 2002. (66) Ireta, J.; Neugebauer, J.; Scheffler, M. On the accuracy of DFT for describing hydrogen bonds: dependence on the bond directionality. J. Phys. Chem. A, 2004, 108, 5692-5698. (67) Sierraalta, A. Cluster Model Approach in Catalysis Research. In Trends in Catalysis Research; Bevy, L. P., Eds., Nova Science Publishers, 2006; pp 103-132. © 2016 Corning Incorporated. All Rights Reserved.

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(68) Grabowsky, S.; Beckmann, J.; Luger, P. The nature of hydrogen bonding involving the siloxane group. Aust. J. Chem., 2011, 65, 785-795. (69) Wojcik, G. M. Thermochemistry of anilines. In The Chemistry of Anilines Part 1. Rappoport, Z., Eds.; Wiley and Sons: London, 2007. (70) Lampman, S. Characterization and failure analysis of plastics. Lampman, S., Eds.; ASM International, 2003.

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