MetalâOrganic Framework Colloids: Disassembly ... - ACS Publications

Subscriber access provided by UCL Library Services

Article

Metal-Organic Framework Colloids: Dis-assembly and De-aggregation Yen-Chih Lai, Chung-Wei Kung, Chun-Hao Su, Kuo-Chuan Ho, Ying-Chih Liao, and De-Hao Tsai Langmuir, Just Accepted Manuscript • DOI: 10.1021/acs.langmuir.6b01530 • Publication Date (Web): 30 May 2016 Downloaded from http://pubs.acs.org on June 1, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Langmuir is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

Metal-Organic Framework Colloids: Dis-assembly and De-aggregation Yen-Chih Lai,1 Chung-Wei Kung,2 Chun-Hao Su,2 Kuo-Chuan Ho,2 Ying-Chih Liao,2,* De-Hao Tsai1,* 1

Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, R.O.C.

2

Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan, R.O.C.

KEYWORDS: Colloid, aggregation, assembly, aqueous, metal-organic framework, pH

ACS Paragon Plus Environment

1

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 21

ABSTRACT

We demonstrate a high-resolution method as an efficient tool to in situ characterize partiallyreversible assembly and aggregation of metal-organic framework (MOF) colloids. Based on the gas-phase electrophoresis, the primary size and the degree of aggregation of the MOF-525 crystals are tunable by pH-adjustment and mobility-selection. These findings allow for the further size control of MOF colloids and prove the capability of semi-quantitative analysis for the MOF-based platforms in a variety of aqueous formulations (e.g., biomedical applications).


2

Page 3 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

1. Introduction Metal–organic frameworks (MOFs), with the exceptionally high surface area, high porosity, low density, and chemically tunable structures, are attractive and widely utilized for a variety of applications in nanotechnology.1-17 Especially in the form of colloidal dispersion, MOFs have raised substiantial interest especially for biomedical applications.18-22 Despite the fact that a considerable amount of work on the synthesis and applications has been reported,23-34 the fundamental understanding about the structural stability of MOF from the perspective of colloidal chemistry is relatvely sparse. As known, MOFs consist of

metal compounds

coordinated to the organic linkers within a single unit cell. Under different aqueous environments, the interactive forces between the individual unit cells changes, inducing the disassembly, de-aggregation, and vice-versa (e.g., MOF-525 depicted in Figure 1). Hence the information regarding to the structural stability of MOF colloids in relevant formulation chemistry and media is very important. The physical sizes, including the sizes of the primary crystal (i.e., primary size) and crystal clusters of MOF colloids (see Fig. 1 using MOF-525 as an example), change with structural stability, affecting their subsequent performance, for example, the efficacy in drug delivery and tumor imaging.18,20,21,27,35-37 Therefore, understanding the structural stability and choosing proper environmental configurations in operations are of crucial importance. The overall performance of MOF colloids can be further improved conceptually by integrating intelligent design principles with the knowledge of structural stability. Our principal objective here is to develop a high-resolution approach for the characterization of the MOF colloids based on gas-phase electrophoresis. The electrospraydifferential mobility analysis (ES-DMA) is employed for the in situ measurement of the mobility size distributions of the MOF colloids (i.e., based on the electrophoretic velocity), and the


3

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 21

electrostatic-directed deposition is used to collect the samples for the ex situ image analyses of the primary size and the morphology of MOF crystals. In comparison to the commonly used light scattering approach,26,27 the superior capability of ES-DMA is to resolve multi-model distributions for colloidal MOF with high polydispersity. This method has shown to be effective for the characterization of particle size. By real-time monitoring the change in mobility size distributions, the colloidal instability (e.g., aggregation, surface dissolution) of either sphere-like or non-spherical nanomaterial colloids can be effectively characterized.38-41 However, the structural stability of nanomaterials determined by the heterogeneous intermolecular bindings (e.g., the linkage between the metallic and organic components in the MOF crystals) has yet to be reported. Our work demonstrates for the first time that the physical size and structural stability of sub-micron and nano-scale MOF colloids can be real-time characterized in an aqueous phase on a semi-quantitative basis.

Figure 1. Crystal structure of MOF-525 and the change in physical dimension via dis-assembly and de-aggregation processes. The primary crystal is composed of a number of unit cells with a cubic length of 1.9 nm.25 Here Lt is the cubic length of MOF-525 primary crystal.

The MOF-525, a zirconium-based MOF with relatively high hydrothermal stability and the chemical stability,19,42-46 is used as a representative in this study. The crystal structure of


4

Page 5 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

MOF-525 and the depiction of the change in physical dimension via dis-assembly and deaggregation processes proposed are shown in Figure 1. Here the MOF-525 crystals were synthesized according to the solvothermal process reported in a recent study.47 Briefly, the nanocrystals of MOF-525 were formed at 80 °C using benzoic acid, zirconyl chloride octahydrate, and mesotetra(4-carboxyphenyl)porphine (H4TCPP) as precursors. After dispersing 2 mg of the MOF-525 crystals in 1 mL of N,N-dimethylformamide, the solvent was then replaced with the de-ionized water to form the aqueous colloids of MOF-525. Subsequently, the sample of MOF-525 colloids was placed in ES-DMA and aerosolized by electrospray ionization (ES) followed by charge neutralization. The electrosprayed particles were delivered to a differential mobility analyzer (DMA) for a real-time monitoring of the mobility size distribution of MOF-525 colloids. Besides, the ES-aerosolized particles (i.e., size-selected or without size classification) were transported to an electrostatic precipitator, where the MOF crystals were deposited onto a silicon wafer for the analyses using scanning electron microscopy (SEM). The schematic diagram of our approach is shown in Figure 2.


5

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 21

Figure 2. Schematic diagram of the gas-phase electrophoresis method, combining a differential mobility analyzer (i.e., for the in-situ characterization of mobility size distribution) and an electrostatic aerosol deposition system (i.e., for the ex-situ image analysis).

2. Experimental 2.1 Materials Meso-tetra(4-carboxyphenyl)porphine (H4TCPP, >97%. Frontier Scientific, Logan, UT, U.S.A.), benzoic acid (≥99.5%. J. T. Baker, Center Valley, PA, U.S.A.), zirconyl chloride octahydrate (99.9%. Alfa Aesar, Lancashire, UK), N,N-Dimethylformamide (DMF, ≥99.8%. Macron, Center Valley, PA, U.S.A.), acetone (J. T. Baker, ≥99.5%). Aqueous ammonium acetate (>98%. Sigma-Aldrich, St. Louis, MO, U.S.A.) solution, nitric acid (1st grade, Union Chemical Works Ltd., Taiwan, R.O.C.), and ammonium hydroxide (>98.5 %, Sigma-Aldrich) were used to


6

Page 7 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

adjust the ionic strength and the pH of the samples, respectively. Biological grade 18.2 MΩ•cm deionized water (Millipore, Billerica, MA, U.S.A.) was used to prepare solutions and aqueous colloidal suspensions.

2.2. Synthesis of MOF-525 crystals and colloids The MOF-525 nanocrystals were synthesized by the procedure as described as follows:23,47 1.35 g of benzoic acid and 105 mg of zirconyl chloride octahydrate were dissolved in 8 mL of DMF in a 20 mL screw-thread scintillation vial using a sonication process. The vial was sealed and heated at 80 oC for 2 hr. After cooling to the room temperature, 47 mg of H4TCPP was added into the solution and reacted for 20 mins. Then the vial was closed and placed on the bottom of a gravity convection oven at 80 oC for 24 hr. After centrifugation, we collected the precipitate in the vial (≈ 42 mg, corresponding to the yield of ≈ 70 %) and then washed with DMF. The MOF colloids in aqueous phase were prepared by replacing the DMF with DI-water as the solvent, and the pH values of MOF colloids were manually adjusted within 5 min.

2.3.Characterization of MOF colloids The electrospray-differential mobility analysis (ES-DMA) was used to obtain a numberbased particle size distribution. In principal, MOF-525 colloids are first aerosolized through ES ionization using an electrospray (ES) aerosol generator (model 3480, TSI Inc., Shoreview, MN, U.S.A.). The aerosolized nanoparticles (NPs) generated from the ES process were immediately charge-neutralized by a Po210 radioactive source following a Boltzmann equilibrium charge


7

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 21

distribution.38,48 Then those particles containing multiple charges (i.e., including positive, neutral, and negative NPs) were delivered to DMA (model 3081, TSI Inc.). Essentially, DMA selects MOF-525 crystals with a narrow distribution based on their electrical mobility. Particles of a specific mobility size, dp,m, that exited the electrostatic classifier were counted by a condensation particle counter (CPC, model 3775, TSI Inc.). An entire distribution can be obtained by sweeping the voltage applied to the DMA and counting the number concentration of MOF-525 with the corresponding electrical mobility. The step size used in the particle size measurements was 2.0 nm and the time interval between each step size was 10 s. Sample flow rate (Qsamp) in the DMA was set to 1.2 L min−1 and sheath flow rate (Qsh) in the DMA was 5.0 L min−1. The uncertainty in the measurement of dp,m was estimated to be 2 nm in this study. Then the aerosolized MOF-525 crystals were delivered to an electrostatic classifier (model 3081, TSI Inc.), where the particles were classified based on their electric mobility under an applied DC electric field. The primary structures and particle sizes of MOF-525 samples were imaged using a scanning electron microscope (SEM, Hitachi SU8010, Hitachi, Japan) operated at (10-20) kV. Aerosolized MOF-525 were delivered to an electrostatic precipitator and deposited onto a silicon chip operated at a sample flow rate of ≈1.5 L min−1 and an electric field of -(2 to 5) kV cm-1. Due to electrostatic repulsion, deposition-induced aggregation is negligible under these conditions. X-ray diffraction (XRD) patterns of the MOF thin films were obtained by an X-ray diffractometer (X-Pert, the Netherlands).

3. Results and Discussion


8

Page 9 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

Figure 3a shows a mobility size (dp,m) distribution of MOF-525 colloids at a neutral pH environment (pH 6.4) measured by ES-DMA. The peak mobility diameter, dp,m*, was ≈150 nm, where the full width at half maximum (FWHM) of the distribution was ≈170 nm. By imaging the size-classified MOF-525 colloids at dp,m=150 nm (Fig. 3b-3c. Additional images were shown in Fig. S2 of the Supporting Information, SI), we observed that the MOF-525 crystals were cubic in primary structure which is considered to be a monomer (n=1. Here n is the number of primary MOF crystal per cluster). The average cubic length, Lt,avg, was ≈149 nm. At dp,m=260 nm (Fig. 3d-3e), we found that the primary size of MOF-525 crystals was relatively unchanged (Lt,avg =156 nm), but the dimers (n=2) were the dominant species. These results suggest that ES-DMA not only can effectively characterize MOF-525 colloids to obtain a full mobility size distribution, but also it provides an useful route for size classification. Moreover, the average number of primary crystals, navg, is proportional to the selected dp,m (i.e., navg increased from 1.7 to 2.2 when the selected dp,m increased from 150 nm to 260 nm), indicating that the aggregation status of MOF colloids can be semi-quantitatively correlated with the moblity size distribution measured by ES-DMA (details of the calculation method of navg and the analysis of Lt,avg to dp,m were shown in Section S1-2 of SI).


9

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 21

Figure 3. Analyses of physical size and the effectiveness in size classification of MOF-525 colloids. (a) Mobility size distribution. (b) Representative SEM image at dp,m=150 nm. (c) Histogram of n at dp,m=150 nm generated from SEM images. Number of particle counts (N): 119. (d) Representative SEM image at dp,m=260 nm. (e) Histogram of n at dp,m=260 nm generated from SEM images. N: 96. pH 6.4.

Figure 4a shows the effect of environmental pH to the mobility size distribution of MOF525 colloids. When the pH value was tuned to 2.5, dp,m* and FWHM decreased to ≈110 nm and ≈82 nm, respectively. Conceptually, the decrease in FWHM is usually related to de-aggregation, and a decrease of dp,m* is mainly attributed to dis-assembly.16,49 Therefore, the result shows the de-aggregation of crystal clusters together with a certain degree of dis-assembly of primary crystals by increasing acidity in the environment. At a basic pH condition (pH 10.6), dp,m* decreased dramatically to ≈32 nm, and the FWHM was less than 70 nm. Combining the information of mobility size distributions of MOF-525 colloids ranging from pH 8 to pH 11 (see Sec. S6 of SI), we concludes that the rate of dis-assembly and de-aggregation of MOF-525


10

Page 11 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

colloids increased with the basicity (i.e., based on the change in dp,m* and FWHM versus the storage time under the specified pH condition). To the best of our knowledge, this is also the first report of the dis-assembly of primary crystals and the de-aggregation of crystal clusters for the MOF colloids in an aqueous phase over various pH conditions. Note that the pH of the sample was manually adjusted, and then the sample was stored under the specified pH condition for at least 48 hr before the measurement (i.e., t>48 hr, where t is the time after pH adjustments). Therefore, the variation of dp,m during the measurement (≈30 mins) was assumed to be negligible. To verify the aforementioned dis-assembly and de-aggregation processes, SEM is employed orthogonally to analyze the physical structures of MOF-525 under various pH conditions. Figure 4b-1 shows the representative SEM image of MOF-525 colloids at pH 6.4. We identify the presence of monomers and finite-sized crystal clusters in the MOF colloids, and the Lt,avg was ≈184 nm (Fig. 4b-2) and navg≈2.1 (Fig. 4b-3) at pH 6.4. By increasing the acidity to pH 2.4, we observed that the morphology of the primary crystal remained cubic (Fig. 4c-1), and the Lt,avg decreased to ≈149 nm (Fig. 4c-2). Besides, navg reduced significantly to ≈1.7 (Fig. 4c3), and the dominant species became monomers (>50% in population). At pH 10.6 (Fig. 4d-1), we observed that the MOF-525 crystals were mainly monomers (≈80%) with a significant change in Lt,avg (≈70 nm. Fig. 4d-2) and navg (≈1.3. Fig. 4d-3). The SEM results were shown to be consistent with the analysis by ES-DMA, demonstrating that we can use ES-DMA to probe the change of primary size and aggregation state of the MOF colloids semi-quantitatively. Note that the information regarding to the crystalline structures of MOF-525 after pH adjustments are included in Fig. S1 of SI, indicating that no phase transition in the framework occurred at an acidic condition (pH 2.7) but a collapse of framework in the major components under a basic


11

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 21

environment (pH 10.6). Therefore, the estimated range of pH adjustment for maintaining the crystalline structure of MOF-525 colloids is from pH 2.4 to pH 8.


12

Page 13 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

Figure 4. Analyses of MOF-525 colloids over various pH environments. t>48 hr. (a) Mobility size distributions of MOF-525 colloids over three pH conditions: pH 2.4, pH 6.4, pH 10.6. (b) SEM analysis at pH 6.4. 1: Representative image; 2: Histogram of Lt. N: 129. 3: Histogram of n. N: 221. (c) SEM analysis at pH 2.4. 1: Representative image. 2: Histogram of Lt. N: 125. 3: Histogram of n. N: 222. (d) SEM analysis at pH 10.6. 1: Representative image; 2: Histogram of Lt. N: 107. 3: Histogram of n. N: 98.


13

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 21

We hypothesize that the mechanism of dis-assembly and de-aggregation of MOF-525 crystals is mainly attributed to the changes in surface chemistry upon protonation and deprotonation. Because the H4TCPP (i.e., the organic compound of the MOF-525 unit cell) contains 4 pyrrole subunits at the centre of unit cell and 4 carboxylic groups in connection with the metallic nodes,25,50 the binding forces between the individual unit cells in a primary crystal can be weakened with an increase of acidity and basicity, resulting in the dis-assembly of primary crystal of MOF-525.33,45,51 Simultaneously, the amine and carboxylic groups inside the unit cells also affect the outer colloidal surface charges (i.e., the isoelectric point is at 5. See Fig. S11 of SI), where the finite-sized MOF-525 crystal clusters can be de-aggregated into monomers due to the decrease in the attractive force between the individual primary crystals of a MOF crystal cluster. We also identify the behaviors of partially reversible assembly and aggregation of the MOF525 colloids. By turning the pH reversely from 2.4 to 6.2 (Fig. 5a), dp,m* and FWHM of MOF525 colloids increased to ≈138 nm and ≈148 nm, respectively. The corresponding SEM image (Fig. 5b) shows that MOF-525 crystals remained cubic with an increase of Lt,avg and navg (i.e., Lt,avg≈162 nm and navg ≈1.5. See Fig. S9-10 of SI). Similarly, by adjusting the pH reversely from pH 10 to ≈pH 7 (Fig. 5c), dp,m* and FWHM of MOF-525 colloids increased to ≈64 nm and ≈70 nm, respectively. The primary structure remained cubic (Fig. 5d) with Lt,avg≈91 nm and navg≈1.5 (See Fig. S9-10 of SI). These results imply a certain extent of re-assembly and re-aggregation through the pH adjustment. However, the MOF-525 crystals are unable to fully reverse to the original state especially from the basic environment (Fig. 5c). A cartoon of the partiallyreversible dis-assembly and de-aggregation processes of MOF-525 colloids is shown in Fig. 5e


14

Page 15 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

based on the results in Fig. 4 and Fig. 5a-d. Note that the mechanism proposed should be only applicable for MOF-525 or other similar MOFs based on the results of this study.

Figure 5. Analyses of reversible assembly and aggregation of MOF-525 colloids. (a) Mobility size distributions from pH 2.4 to pH 6.2. t=48 hr. (b) Representative SEM image from pH 2.4 to pH 6.2. t=48 hr. (c) Mobility size distributions from pH 10 to pH 7. t=2 hr. (d) Representative SEM image from pH 10 to pH 7. t=2 hr. (e) Cartoon depictions of partially-reversible assembly and aggregation of MOF-525 colloids.

4. Conclusions We successfully characterize and optimize MOF-525 colloids by using the gas-phase electrophoresis method. For the first time, we report partially reversible assembly and


15

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 21

aggregation behaviors of MOF colloids through pH adjustments, providing an effective route to control the primary size as well as the size homogeneity. Besides, ES-DMA can be very useful in improving size homogeneity for the low-density MOF crystals at the sub-micron and nanoscale, which are known to be inseparable via the traditional centrifugation-based approach. This work can provide a prototype study for a variety of MOF colloids, and the results provide beneficial guidelines for the aqueous formulation chemistry of MOF-based platforms (e.g., metalation) and the subsequent electrospray-assisted device integration.

Supporting Information. Calculation of equivalent mobility size, comparison to the cubic length of MOF-525, average number of primary crystals, analysis of the crystalline structure of MOF-525 using XRD, additional SEM images and histograms of Lt and n, zeta potentials of MOF-525 colloids, additional mobility size distributions of MOF-525 colloids. This material is avail-able free of charge via the Internet at http://pubs.acs.org.

* AUTHOR INFORMATION Corresponding Author *

De-Hao Tsai

[email protected] Tel: 886-3-516-9316 *

Ying-Chih Liao


16

Page 17 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

[email protected] Tel: 886-2-3366-9688

Notes The authors declare no competing financial interests.

ACKNOWLEDGMENT The authors thank the Ministry of Science and Technology (MOST) of Taiwan and the Office of Naval Research Global, U.S.A. for financial support under Contract MOST104-2221-E-007-128, MOST103-2923-E-002-010-MY3 and ONRG N62909-15-1-N061. The authors thank Prof. Rong-Ming Ho and Dr. Mohan Raj Krishnan at NTHU for the helpful discussion.

REFERENCES (1) Furukawa, H.; Muller, U.; Yaghi, O. M. "Heterogeneity within Order" in Metal-Organic Frameworks. Angew Chem Int Edit 2015, 54, 3417-3430. (2) Yuan, S.; Lu, W. G.; Chen, Y. P.; Zhang, Q.; Liu, T. F.; Feng, D. W.; Wang, X.; Qin, J. S.; Zhou, H. C. Sequential Linker Installation: Precise Placement of Functional Groups in Multivariate Metal-Organic Frameworks. J Am Chem Soc 2015, 137, 3177-3180. (3) Mondloch, J. E.; Katz, M. J.; Isley, W. C.; Ghosh, P.; Liao, P. L.; Bury, W.; Wagner, G.; Hall, M. G.; DeCoste, J. B.; Peterson, G. W.; Snurr, R. Q.; Cramer, C. J.; Hupp, J. T.; Farha, O. K. Destruction of chemical warfare agents using metal-organic frameworks. Nat Mater 2015, 14, 512-516. (4) Furukawa, H.; Cordova, K. E.; O'Keeffe, M.; Yaghi, O. M. The Chemistry and Applications of Metal-Organic Frameworks. Science 2013, 341, 974-+. (5) Li, J. R.; Sculley, J.; Zhou, H. C. Metal-Organic Frameworks for Separations. Chem Rev 2012, 112, 869-932. (6) Kreno, L. E.; Leong, K.; Farha, O. K.; Allendorf, M.; Van Duyne, R. P.; Hupp, J. T. MetalOrganic Framework Materials as Chemical Sensors. Chem Rev 2012, 112, 1105-1125. (7) Murray, L. J.; Dinca, M.; Long, J. R. Hydrogen storage in metal-organic frameworks. Chem Soc Rev 2009, 38, 1294-1314.


17

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 21

(8) Taylor-Pashow, K. M. L.; Della Rocca, J.; Xie, Z. G.; Tran, S.; Lin, W. B. Postsynthetic Modifications of Iron-Carboxylate Nanoscale Metal-Organic Frameworks for Imaging and Drug Delivery. J Am Chem Soc 2009, 131, 14261-+. (9) Kuo, C. H.; Tang, Y.; Chou, L. Y.; Sneed, B. T.; Brodsky, C. N.; Zhao, Z. P.; Tsung, C. K. Yolk-Shell Nanocrystal@ZIF-8 Nanostructures for Gas-Phase Heterogeneous Catalysis with Selectivity Control. J Am Chem Soc 2012, 134, 14345-14348. (10) Chaikittisilp, W.; Ariga, K.; Yamauchi, Y. A new family of carbon materials: synthesis of MOF-derived nanoporous carbons and their promising applications. J Mater Chem A 2013, 1, 14-19. (11) Dang, G. H.; Vu, Y. T. H.; Dong, Q. A.; Le, D. T.; Truong, T.; Phan, N. T. S. Quinoxaline synthesis via oxidative cyclization reaction using metal-organic framework Cu(BDC) as an efficient heterogeneous catalyst. Appl Catal a-Gen 2015, 491, 189-195. (12) Li, S. Z.; Huo, F. W. Metal-organic framework composites: from fundamentals to applications. Nanoscale 2015, 7, 7482-7501. (13) Vargas, E.; Snurr, R. Q. Heterogeneous Diffusion of Alkanes in the Hierarchical MetalOrganic Framework NU-1000. Langmuir 2015, 31, 10056-10065. (14) Lim, W. X.; Thornton, A. W.; Hill, A. J.; Cox, B. J.; Hill, J. M.; Hill, M. R. High Performance Hydrogen Storage from Be-BIB Metal-Organic Framework at Room Temperature. Langmuir 2013, 29, 8524-8533. (15) Forrest, K. A.; Pham, T.; Georgiev, P. A.; Pinzan, F.; Cioce, C. R.; Unruh, T.; Eckert, J.; Space, B. Investigating H-2 Sorption in a Fluorinated Metal-Organic Framework with Small Pores Through Molecular Simulation and Inelastic Neutron Scattering. Langmuir 2015, 31, 7328-7336. (16) Tai, J.-T.; Lai, C.-S.; Ho, H.-S.; Yeh, Y.-S.; Wang, H.-F.; Ho, R.-M.; Tsai, D.-H. Protein– Silver Nanoparticle Interactions to Colloidal Stability in Acidic Environments. Langmuir 2014, 30, 12755–12764. (17) Tsai, D. H.; Cho, T. J.; DelRio, F. W.; Gorham, J. M.; Zheng, J. W.; Tan, J. J.; Zachariah, M. R.; Hackley, V. A. Controlled Formation and Characterization of Dithiothreitol-Conjugated Gold Nanoparticle Clusters. Langmuir 2014, 30, 3397-3405. (18) McKinlay, A. C.; Morris, R. E.; Horcajada, P.; Ferey, G.; Gref, R.; Couvreur, P.; Serre, C. BioMOFs: Metal-Organic Frameworks for Biological and Medical Applications. Angew Chem Int Edit 2010, 49, 6260-6266. (19) Feng, D. W.; Gu, Z. Y.; Li, J. R.; Jiang, H. L.; Wei, Z. W.; Zhou, H. C. ZirconiumMetalloporphyrin PCN-222: Mesoporous Metal-Organic Frameworks with Ultrahigh Stability as Biomimetic Catalysts. Angew Chem Int Edit 2012, 51, 10307-10310. (20) Hanke, M.; Arslan, H. K.; Bauer, S.; Zybaylo, O.; Christophis, C.; Gliemann, H.; Rosenhahn, A.; Woll, C. The Biocompatibility of Metal-Organic Framework Coatings: An Investigation on the Stability of SURMOFs with Regard to Water and Selected Cell Culture Media. Langmuir 2012, 28, 6877-6884. (21) Horcajada, P.; Gref, R.; Baati, T.; Allan, P. K.; Maurin, G.; Couvreur, P.; Ferey, G.; Morris, R. E.; Serre, C. Metal-Organic Frameworks in Biomedicine. Chem Rev 2012, 112, 1232-1268. (22) Sindoro, M.; Yanai, N.; Jee, A. Y.; Granick, S. Colloidal-Sized Metal-Organic Frameworks: Synthesis and Applications. Accounts Chem Res 2014, 47, 459-469. (23) Kung, C. W.; Chang, T. H.; Chou, L. Y.; Hupp, J. T.; Farha, O. K.; Ho, K. C. Post metalation of solvothermally grown electroactive porphyrin metal-organic framework thin films. Chem Commun 2015, 51, 2414-2417.


18

Page 19 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

(24) Lin, H. Y.; Chin, C. Y.; Huang, H. L.; Huang, W. Y.; Sie, M. J.; Huang, L. H.; Lee, Y. H.; Lin, C. H.; Lii, K. H.; Bu, X. H.; Wang, S. L. Crystalline Inorganic Frameworks with 56-Ring, 64-Ring, and 72-Ring Channels. Science 2013, 339, 811-813. (25) Morris, W.; Volosskiy, B.; Demir, S.; Gandara, F.; McGrier, P. L.; Furukawa, H.; Cascio, D.; Stoddart, J. F.; Yaghi, O. M. Synthesis, Structure, and Metalation of Two New Highly Porous Zirconium Metal-Organic Frameworks. Inorg Chem 2012, 51, 6443-6445. (26) Carne-Sanchez, A.; Imaz, I.; Cano-Sarabia, M.; Maspoch, D. A spray-drying strategy for synthesis of nanoscale metal-organic frameworks and their assembly into hollow superstructures. Nat Chem 2013, 5, 203-211. (27) Horcajada, P.; Chalati, T.; Serre, C.; Gillet, B.; Sebrie, C.; Baati, T.; Eubank, J. F.; Heurtaux, D.; Clayette, P.; Kreuz, C.; Chang, J. S.; Hwang, Y. K.; Marsaud, V.; Bories, P. N.; Cynober, L.; Gil, S.; Ferey, G.; Couvreur, P.; Gref, R. Porous metal-organic-framework nanoscale carriers as a potential platform for drug delivery and imaging. Nat Mater 2010, 9, 172178. (28) Hu, M.; Belik, A. A.; Imura, M.; Yamauchi, Y. Tailored Design of Multiple Nanoarchitectures in Metal-Cyanide Hybrid Coordination Polymers. J Am Chem Soc 2013, 135, 384-391. (29) Chou, L. Y.; Hu, P.; Zhuang, J.; Morabito, J. V.; Ng, K. C.; Kao, Y. C.; Wang, S. C.; Shieh, F. K.; Kuo, C. H.; Tsung, C. K. Formation of hollow and mesoporous structures in singlecrystalline microcrystals of metal-organic frameworks via double-solvent mediated overgrowth. Nanoscale 2015, 7, 19408-19412. (30) Liu, L. L.; Song, Y. B.; Chong, H. B.; Yang, S.; Xiang, J.; Jin, S.; Kang, X.; Zhang, J.; Yu, H. Z.; Zhu, M. Z. Size-confined growth of atom-precise nanoclusters in metal-organic frameworks and their catalytic applications. Nanoscale 2016, 8, 1407-1412. (31) Shah, M. N.; Gonzalez, M. A.; McCarthy, M. C.; Jeong, H. K. An Unconventional Rapid Synthesis of High Performance Metal-Organic Framework Membranes. Langmuir 2013, 29, 7896-7902. (32) Pham, M. H.; Vuong, T.; Vu, A. T.; Do, T. O. Novel Route to Size-Controlled Fe-MIL88B-NH2 Metal-Organic Framework Nanocrystals. Langmuir 2011, 27, 15261-15267. (33) Zhao, N.; Sun, F. X.; Zhang, S. X.; He, H. M.; Liu, J.; Li, Q.; Zhu, G. S. DeprotonationTriggered Stokes Shift Fluorescence of an Unexpected Basic-Stable Metal-Organic Framework. Inorg Chem 2015, 54, 65-68. (34) Fernandez, C. A.; Nune, S. K.; Motkuri, R. K.; Thallapally, P. K.; Wang, C. M.; Liu, J.; Exarhos, G. J.; McGrail, B. P. Synthesis, Characterization, and Application of Metal Organic Framework Nanostructures. Langmuir 2010, 26, 18591-18594. (35) Cai, W.; Chu, C. C.; Liu, G.; Wang, Y. X. J. Metal-Organic Framework-Based Nanomedicine Platforms for Drug Delivery and Molecular Imaging. Small 2015, 11, 4806-4822. (36) Zhuang, J.; Kuo, C. H.; Chou, L. Y.; Liu, D. Y.; Weerapana, E.; Tsung, C. K. Optimized Metal-Organic-Framework Nanospheres for Drug Delivery: Evaluation of Small-Molecule Encapsulation. Acs Nano 2014, 8, 2812-2819. (37) Wang, X. G.; Dong, Z. Y.; Cheng, H.; Wan, S. S.; Chen, W. H.; Zou, M. Z.; Huo, J. W.; Deng, H. X.; Zhang, X. Z. A multifunctional metal-organic framework based tumor targeting drug delivery system for cancer therapy. Nanoscale 2015, 7, 16061-16070. (38) Tai, J. T.; Lai, Y. C.; Yang, J. H.; Ho, H. C.; Wang, H. F.; Ho, R. M.; Tsai, D. H. Quantifying Nanosheet Graphene Oxide Using Electrospray-Differential Mobility Analysis. Anal Chem 2015, 87, 3884-3889.


19

Langmuir

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 21

(39) Tsai, D. H.; DelRio, F. W.; Keene, A. M.; Tyner, K. M.; MacCuspie, R. I.; Cho, T. J.; Zachariah, M. R.; Hackley, V. A. Adsorption and Conformation of Serum Albumin Protein on Gold Nanoparticles Investigated Using Dimensional Measurements and in Situ Spectroscopic Methods. Langmuir 2011, 27, 2464-2477. (40) Tsai, D. H.; Cho, T. J.; Elzey, S. R.; Gigault, J. C.; Hackley, V. A. Quantitative analysis of dendron-conjugated cisplatin-complexed gold nanoparticles using scanning particle mobility mass spectrometry. Nanoscale 2013, 5, 5390-5395. (41) Tsai, D. H.; Elzey, S.; DelRio, F. W.; Keene, A. M.; Tyner, K. M.; Clogston, J. D.; MacCuspie, R. I.; Guha, S.; Zachariah, M. R.; Hackley, V. A. Tumor necrosis factor interaction with gold nanoparticles. Nanoscale 2012, 4, 3208-3217. (42) Mouchaham, G.; Cooper, L.; Guillou, N.; Martineau, C.; Elkaim, E.; Bourrelly, S.; Llewellyn, P. L.; Allain, C.; Clavier, G.; Serre, C.; Devic, T. A Robust Infinite Zirconium Phenolate Building Unit to Enhance the Chemical Stability of Zr MOFs. Angew Chem Int Edit 2015, 54, 13297-13301. (43) Kung, C. W.; Chang, T. H.; Chou, L. Y.; Hupp, J. T.; Farha, O. K.; Ho, K. C. Porphyrinbased metal-organic framework thin films for electrochemical nitrite detection. Electrochem Commun 2015, 58, 51-56. (44) Yang, Q. Y.; Vaesen, S.; Ragon, F.; Wiersum, A. D.; Wu, D.; Lago, A.; Devic, T.; Martineau, C.; Taulelle, F.; Llewellyn, P. L.; Jobic, H.; Zhong, C. L.; Serre, C.; De Weireld, G.; Maurin, G. A Water Stable Metal-Organic Framework with Optimal Features for CO2 Capture. Angew Chem Int Edit 2013, 52, 10316-10320. (45) Jiang, H. L.; Feng, D. W.; Wang, K. C.; Gu, Z. Y.; Wei, Z. W.; Chen, Y. P.; Zhou, H. C. An Exceptionally Stable, Porphyrinic Zr Metal-Organic Framework Exhibiting pH-Dependent Fluorescence. J Am Chem Soc 2013, 135, 13934-13938. (46) Guillerm, V.; Ragon, F.; Dan-Hardi, M.; Devic, T.; Vishnuvarthan, M.; Campo, B.; Vimont, A.; Clet, G.; Yang, Q.; Maurin, G.; Ferey, G.; Vittadini, A.; Gross, S.; Serre, C. A Series of Isoreticular, Highly Stable, Porous Zirconium Oxide Based Metal-Organic Frameworks. Angew Chem Int Edit 2012, 51, 9267-9271. (47) Chang, T. H.; Kung, C. W.; Chen, H. W.; Huang, T. Y.; Kao, S. Y.; Lu, H. C.; Lee, M. H.; Boopathi, K. M.; Chu, C. W.; Ho, K. C. Planar Heterojunction Perovskite Solar Cells Incorporating Metal-Organic Framework Nanocrystals. Advanced Materials 2015, 27, 7229-+. (48) Hinds, W. C. Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles; Second ed.; John Wiley & Sons, 1999. (49) Pease, L. F.; Tsai, D. H.; Brorson, K. A.; Guha, S.; Zachariah, M. R.; Tarlov, M. J. Physical Characterization of Icosahedral Virus Ultra Structure, Stability, and Integrity Using Electrospray Differential Mobility Analysis. Anal Chem 2011, 83, 1753-1759. (50) Gao, W. Y.; Chrzanowski, M.; Ma, S. Q. Metal-metalloporphyrin frameworks: a resurging class of functional materials. Chem Soc Rev 2014, 43, 5841-5866. (51) DeCoste, J. B.; Peterson, G. W.; Jasuja, H.; Glover, T. G.; Huang, Y. G.; Walton, K. S. Stability and degradation mechanisms of metal-organic frameworks containing the Zr6O4(OH)(4) secondary building unit. J Mater Chem A 2013, 1, 5642-5650.


20

Page 21 of 21

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Langmuir

Table of Contents Graphic and Synopsis


21

MetalâOrganic Framework Colloids: Disassembly ... - ACS Publications

Recommend Documents

MetalâOrganic Framework Colloids: Disassembly ... - ACS Publications