Reaction Kinetics at PDMS-E Emulsion Droplets-Gelatin Interface

Subscriber access provided by Iowa State University | Library

Interfaces: Adsorption, Reactions, Films, Forces, Measurement Techniques, Charge Transfer, Electrochemistry, Electrocatalysis, Energy Production and Storage

Reaction Kinetics at PDMS-E Emulsion Droplets-Gelatin Interface Huijun Ma, Yuai Hua, Cong Zhu, Zhaosheng Hou, Bo Zhao, Yongli Pu, Zhaoning Cai, Liangli Zhang, Tianduo Li, and Jing Xu Langmuir, Just Accepted Manuscript • DOI: 10.1021/acs.langmuir.8b03633 • Publication Date (Web): 04 Jan 2019 Downloaded from http://pubs.acs.org on January 5, 2019

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 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 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.

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 27 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

Reaction Kinetics at PDMS-E Emulsion Droplets-Gelatin Interface

Huijun Ma,a Yuai Hua,a Cong Zhu,a Zhaosheng Hou,b Bo Zhao,a Yongli Pu,a Zhaoning Cai,a Liangli Zhang,a Tianduo Lia and Jing Xua,*

aShandong

Provincial Key Laboratory of Molecular Engineering, School of Chemistry and

Pharmaceutical Engineering; College of Mathematics and Statistics, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, P. R. China bCollege

of Chemistry, Chemical Engineering and Materials Science, Shandong Normal

University, Jinan 250100, P. R. China

1

ACS Paragon Plus Environment

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

ABSTRACT:

In

this

work,

interfacial

Page 2 of 27

reaction

kinetics

between

α-[3-(2,3-epoxypropoxy) propyl]-ω-butyl-polydimethylsiloxane (PDMS-E) emulsion droplets with different sizes and gelatin was studied. The results of amino conversion rate determination show that the reaction proceeded in two steps. Fluorescence spectra analysis indicates that step 1 (0-2 h) should be the adsorption of gelatin on droplet surface. In step 2 (2-13 h), amino conversion rate increased rapidly. The reaction rate in step 2 (k2) was obtained by using the 2th-order approach to model the grafting reaction kinetics. The quantitative relationships among amino conversion rate, droplet size, the concentration of surfactant, reaction temperature and time were described by linear regression models in given ranges of conditions in step 2. Thermodynamic analysis indicates that the interfacial reaction is an endothermic reaction. After 13 h, the reaction was almost stopped.

KEYWORDS: Interfacial reaction; kinetics; droplet size; amino conversion rate; regression models

2


Page 3 of 27 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

INTRODUCTION Organic reactions in systems containing two immiscible phases have important applications in chemical, pharmaceutical, electrochemical and polymer synthesis.1-4 This is attributed to the design of commercial polymer composites with biphasic properties. The reaction between two compounds in different phases of a mixture is often inhibited because of the inability of reagents to come together. Organic reactions in a heterogeneous mixture of reactants and water have been found to proceed dramatically faster than those in a homogeneous mixture.5-9 Under the “on water” condition, the reactive groups on the organic-water interface have been proven crucial to accelerate the reaction.10-17 The density of reactive groups at the organic-water interface is determined by many factors, such as charge density,18 mass transfer,7,19,20 temperature21,22 and particle size.23 Suen and Morawetz studied the reaction of monodisperse poly(vinylbenzy1 chloride) latex with nucleophiles in aqueous phase, and the particle size and surface charge were varied systematically over a wide range. The nucleophilic attack by amines in the aqueous phase was then followed by the release of chloride.18 Zhu indicated that the accumulation of reactant in interfacial region affected the efficient mass transfer between immiscible phases.20 Guo et al. investigated the “on water” reaction in static droplets. Without vigorous stirring, vortexing or ultrasonication, the organic-water interface effectively accelerated the “on water” reaction to the same level as in bulk solution, indicating that the organic-water interface was the major catalytic factor and hydrodynamic factors were insignificant for the “on water” reaction.9 Reaction at the interface of two immiscible liquids has been proven to have enhanced kinetics, higher yields and higher selectivity in certain conditions.24 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

It has been reported that the interface reaction between PDMS-E and gelatin provides a template for studying the interface reaction where the interfacial composition can be tuned when the latex particles are prepared using polymer with low Tg.23 The results showed that the charge density or reactive groupson the surface of latex particle responded to particle size because of low Tg of PDMS-E. The results indicated that the charge density and the distribution concentration of reactive groups on the surface of emulsion droplets were closely related to the droplet size, on which basis the reaction could be made controllable. A small droplet is often protected by a tight surface layer, which results in the shielding of reactive groups. With increase in droplet size, the interfacial layer becomes looser and reactive groups migrate to the surface of the droplet, leading to rapid increase in reaction rate. Protein adsorption plays an important role in affecting interfacial reaction.25-27 Sarobe et al. studied the covalent immobilization of the model protein lysozyme and monitored the extent to which the protein was bound to the monodisperse latex particles with surface chloromethyl groups. Their results indicated that all adsorbed proteins could be covalently bound if a certain surface density of functional groups was achieved. They also explained that the first contact between the protein and surface was always physical and then chemical linking ocurred.28 This view has been discussed by many reports.29-33 Gonzalez et al. indicated that biomolecules are attached onto latex particles either by simple physical adsorption or by covalent coupling.31 Taniguchi et al. explained that the adsorption of biomolecules onto solid supports mostly relied on hydrophobic forces, electrostatic interactions and hydrogen bonding.32 However, the effect of droplet size on protein adsorption has been rarely reported.

4


Page 4 of 27

Page 5 of 27 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

Clarification of the heterogeneous reaction between polymer molecules remains challenging. If a model is proposed to clearly describe the relationship among droplet size, surfactant concentration and conversion rate, then the interfacial reaction can be surely controlled in a certain way. Moreover, factors such as temperature, pH value and reaction time also affect the interfacial reaction through disturbing the system stability or affecting the reaction efficiency.34-36 Even if all other factors remain unchanged, the factor investigated can only vary within a certain range. In other words, there is a synergy between these factors. Kinetic study is an excellent method to reveal the nature of reaction and mathematical method can provide a clear model for guidance. In this study, the interfacial reaction kinetics between monodispersed PDMS-E emulsion droplets with different sizes and gelatin was investigated. The effects of droplet size and relative factors on the interfacial reaction were studied systemically with statistics method. The aim of the work is to give a quantitative equation for controlling the interfacial reaction. The results can provide useful information to regulate the oil/water biphasic reactions. EXPERIMENT Materials Sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS) were purchased from Alfa Aesar (Shanghai, China) and recrystallized from ethanol before use. Allyl glycidyl ether (AGE) and glacial acetic acid were also purchased from Alfa Aesar.

Hexamethylcyclotrisiloxane

(D3),

n–butyllithium

(C4H9Li)

and

chlorodimethylsilane (C2H7ClSi) were purchased from Sigma Aldrich. Benzene and tetrahydrofuran (THF) were purchased from China National Pharmaceutical Group 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

Corporation (Beijing, China) and were purified and strictly dehydrated before use. SPG membrane with 0.5-µm pore size was purchased from China National Pharmaceutical Group Corporation. Type A gelatin from pigskin was purchased from China National Pharmaceutical Group Corporation and used after dialysis. The molecular weight (Mw) of gelatin was determined by Gel Permeation Chromatography (GPC, see Supporting Information (SI), Table S1). Results indicated that the Mw of the gelatin was about 1.40×105 g mol-1 and Mw/Mn was 1.43. The content of primary amino groups in the gelatin was determined by the Van Slyke method at 50 ℃ and was 4.95×10-4 g mol-1. Van Slyke method is a professional method used to determine the content of amino groups in amino acid or protein molecules. When amino acid or protein is added into nitrous acid, the nitrous acid begins to react with the free amino groups in the amino acid or protein. This reaction serves as the basis of the Van Slyke method for the quantitative determination of free amino groups,37 and the testing error of the content of free amino groups in gelatin was below 1%.23 Synthesis of PDMS-H and PDMS-E D3, C4H9Li and C2H7ClSi were used to synthesize polydimethylsiloxanes with Si-H group at one end (PDMS-H) through anionic polymerization. The molar ratio of D3:C4H9Li:C2H7ClSi was about 2:4:1. First, 10 mL of benzene was added to a flask and then 24 mL of C4H9Li was added. After reducing pressure and ventilation with argon gas, 45.99 g of D3 resolved in 40 mL of benzene was added to the flask. After reaction for 30 min, 50 mL of THF was added into the flask for reacting for 8 h. Then, 11 mL of C2H7ClSi was injected into the flask to stop the reaction. Subsequently, the 6


Page 6 of 27

Page 7 of 27 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

products were purified and 45.44 g of PDMS-H was obtained. The yield of PDMS-H was 56.11%. Next, 8.51 g of AGE was added to a flask and argon was then injected into the flask. The molar ratio of PDMS-H to AGE was about 1.6:1. After 30 min, about 40 µL of isopropanol-Pt was injected to the flask. Argon was continually injected, and the temperature of the flask was enhanced to 80 oC. PDMS-H started to be added at a speed of 1 drop per 2 s. Then, the temperature of the flask continued to be enhanced to 110 oC. After reaction for 6 h, the products (PDMS-E) were purified. The yield of PDMS-E was about 84.32%. The obtained PDMS-H were used to synthesize

α-[3-(2,3-epoxy-propoxy)propyl]-ω-butyl-polydimethylsiloxanes

(PDMS-E, Tg -127 oC, for the preparation scheme, see Figure S1). Weight-average molecular weight and relative weight-average molecular weight (Mw=1.14×103 g mol-1, Mw/Mn = 1.16, Table S1) were measured on Waters 150C GPC equipped with three Ultrastyragel columns (500, 103, 104 Å) in series and refractory index detector (RI 2414) at 30 oC using monodisperse polystyrene as calibration standard. THF was used as eluent at a flow rate of 1.0 mL min-1. 1H NMR spectra of PDMS-H and PDMS-E are shown in Figure S1. Preparation of PDMS-E emulsion droplets using SPG membrane PDMS-E, as a dispersed phase, was added to 200 mL of deionized (DI) water containing SDS, SDBS and glacial acetic acid (about 0.05 mL) to form PDMS-E-in-water emulsion (Table S2). The total concentration of surfactants ranged

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

from 0.25 to 0.75 wt %. Dispersed phase (about 2.000 g) passed through the SPG membrane pores under various nitrogen pressures. The process was in accordance with literature38. Finally, emulsion droplets with different sizes were obtained by changing the SDS/SDBS ratio (w/w). Reaction kinetics at PDMS-E emulsion droplets-gelatin interface All gelatin samples were prepared from a stock solution of gelatin to minimize experimental errors. The stock solution was prepared by dissolving gelatin in distilled water (5 wt %), and after 3 h the gelatin solution was heated to 50 oC to ensure the complete dissolution of gelatin. Subsequently, the pH of each prepared gelatin solution was adjusted to 10.0 using sodium hydroxide solution (NaOH, 2.0 mol L-1). Then, the above prepared PDMS-E emulsion was added to the gelatin solution at a rate of 20 drops min-1 with stirring at 50 oC until the predesigned PDMS-E/gelatin ratio was reached. The reaction was continued for 24 h. The content of free amino groups was determined by the Van Slyke method. Then, the difference in conversion rate of amino groups was analyzed as related to the difference in the size of emulsion droplets. Characterization The physical size and polymer dispersity index (PDI) of emulsion droplets were measured using a laser particle analyzer (Zetasizer 2000, Malven Instruments, UK). The instrument, on the basis of Mie-scattering theory, could convert the diffraction

8


Page 8 of 27

Page 9 of 27 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

patterns to particle-size distribution curves and use electrophoresis to measure the Zeta potential. Firstly, the emulsion was carefully put into a color matching test tube. Then, the tube was put into the ZetaSizer 2000 laser particle instrument to measure the PDI or electrophoretic mobility (Zeta potential). Optical microscopic (OM) images were obtained by using an optical microscope (Leica Microsystems GmbH, Germany) equipped with a Lecia DFC 420C CCD image capturing system. The magnification was 400X. Fluorescence spectra of the reaction samples from the reaction solutions with different time were recorded with a HITACHI F-4600 (Hitachi, Japan). Corrections for the background were made. Broader features were observed in the ultraviolet region (the strongest at 459 nm). Experimental data analysis method and mathematical model To reveal the relationship among droplet size, reaction time and amino conversion rate, two-dimensional scatter plots of reaction time-primary amino conversion under different emulsion droplet radii and three-dimensional scatter plots of droplet size-reaction time-amino conversion rate were obtained by using the statistical software OriginPro9.0. These scatter plots show obvious characteristics: from 0 to 2 h (step 1), amino conversion rate increased little; from 2 to 13 h (step 2), amino conversion rate increased monotonously with the extension of reaction time; from 13

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 27

to 24 h, amino conversion rate hardly varied with the reaction time. In view of this, regression analysis was performed on the different stages of reaction. A linear regression model was firstly fitted to describe the linear relationship among droplet size, reaction time and amino conversion rate in step 2: C-NH2(%) = β0 + β1× r +β2×t

(1)

where C-NH2% represents amino conversion rate, r is droplet size and t is reaction time. r and t were called predictor variables, and C-NH2 was called response variable. β0, β1 and β2 were coefficients. A linear regression model was also fitted to describe the linear relationship among droplet size, surfactant concentration and amino conversion rate in step 2: C-NH2(%) = β0 + β1× r +β2× d%

(2)

where d% represents the concentration of surfactant. A linear regression model was fitted to describe the relationship among reaction temperature, reaction time and amino conversion rate in step 2: C-NH2(%) = β0 + β1× r ++ β2× t +β3×T

(3)

where T represents the reaction temperature. Once a regression model was constructed with the statistical software OriginPro9.0, the goodness of fit or coefficient of determination of the model (R2), and the p-values of the estimated parameters β0, β1, β2 and β3 were simultaneously given in the printout.39 The goodness of fit of a regression model describes how well a set of

10


Page 11 of 27 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

observations fit the model and typically summarizes the discrepancy between observed values and the values expected under the model. The higher the goodness of fit, the better the observations fit the model. p-value is defined as the probability of obtaining a result equal to or more extreme than what is actually observed under the null hypothesis, e.g. ‘β0= 0’, ‘β1= 0’, ‘β2= 0’ or ‘β3= 0’ in this paper. The smaller the p-value, the higher the significance of the null hypothesis not adequately explaining the observations. In other words, the p-value of a hypothesis ‘βi= 0’ represents the significance of the influence of the corresponding predictor variable. Specifically, ‘p-value = 1’ implies that the corresponding predictor variable may be negligible and ‘p-value = 0’ implies that the corresponding predictor variable is indispensable in the model. To put it in another way, ‘p-value = 0’ means that the corresponding predictor variable plays a very important role in the model and it is then declared that the regression is highly significant. RESULTS AND DISCUSSION Preparation of monodisperse PDMS-E emulsion droplets The preparation of monodisperse PDMS-E droplets was in accordance with our previous report.23 In this work, a liquid of PDMS-E was passed through the SPG membrane under a given pressure (P) into an aqueous solution (pH =3.75, adjusted by glacial acetic acid) containing SDS and SDBS surfactants. The total concentration of SDS and SDBS was set to 0.25 wt %, 0.50 wt % and 0.75 wt %, respectively.

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

Emulsion droplets were detached from the pores due to the shear force applied by the stirrer in the continuous phase. SDS and SDBS were rapidly adsorbed at the interface between the generated PDMS-E droplets and water to stabilize the emulsion droplets. As shown in Figure 1a–f, monodisperse PDMS-E emulsion droplets were successfully prepared using the SPG membranes with a mean pore size of 0.5 μm. The average diameters of emulsion droplets were 228.4±50, 353.3±47, 464.5±60, 553.6±53, 692.4±48 and 732±48 nm at three different total concentrations of SDS and SDBS, respectively. The size of emulsion droplets was adjusted by changing the total concentration of SDS and SDBS as well as the SDS/SDBS ratio (w/w). Under each preparation condition, the droplets showed a narrow distribution of sizes, as indicated by the small coefficients of variation (CV, 0, then the model 3 can be transferred to: 24.67× t + 6.57×T˃r –230.7

(4)

Obviously, it means that higher temperature or longer time should be provided with enhancing the droplet size. Compared with temperature, however, small droplet size had less influence on reaction rate. When the droplet size is smaller than 230.7 nm, the influence of droplet size can be ignored. In the model, the p-values of hypothesis tests for all coefficients in the linear regression model (3) were 0 and the goodness of fit of the model was 0.981, meaning that the model highly reflected a linear relationship among these variables. The detailed values of k at different temperatures are shown in Table S4. The reaction rate increased with increase in temperature (Figure 4b). The ratios of reaction rates followed the following order: k50/k45 > k45/k40 > k55/k50. The values of k45/k40 and k55/k50 were close to 1, which illustrates that the reaction rate could hardly 18


Page 19 of 27 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

increase in these two temperature ranges. It is well-known that the movement rate of molecules increases gradually with increase in temperature, which can enhance the effective collision between amino groups and epoxy group on the surface of droplet. This is conducive to the interfacial chemical reaction and can lead to increase in k. The conversion rate reached its maximum at 55 ℃, as shown in Figure S4 and the optimal range of temperature was suggested to be 45–50 ℃. After 13 h, the reaction was almost stopped, which was attributed to the depletion of epoxy and amino groups at the interface. The functional groups at the interface were not enough to support the formation of a considerable amount of covalent bonds. Therefore, the conversion rate tended to remain unchanged (Figure 2b). In sum, the interfacial reaction included adsorption and covalent bonding, as shown in Figure 5.

Figure 5. Simulated diagram for description the process of the interface reaction.

CONCLUSIONS In this paper, reaction kinetics at the interface between PDMS-E emulsion droplets and gelatin was studied. Gelatin adsorbed firstly on the surface of droplets through the interaction between gelatin and surfactants within the first 2 h. Later, amino conversion rate increased rapidly as the density of functional groups at the interface 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

reached a certain level during 2-13 h. The droplet size was found to be positively correlated with the conversion rate of amino groups at a constant temperature. In comparison, the concentration of surfactant was found to be negatively correlated with amino conversion rate. The regression analysis showed that the conversion rate was positively correlated with the influence of temperature but negatively correlate with droplet size when the temperature increased within the range of 40-55 oC. In the model, comparing with the effect of temperature, the influence of droplet size can be ignored as the droplet size was smaller than 230.7 nm. After 13 h, the interfacial reaction tended to be finished.

ASSOCIATED CONTENT Supporting Information. The molecular weight characterization of the gelatin by Gel Permeation chromatography (GPC); 1H NMR spectra of PDMS-H and PDMS-E; the dosages of materials used for the preparation of PDMS-E emulsion droplets using SPG membrane; the nth-order approach to model the grafting reaction kinetics; thermodynamic parameters were determined using the Arrhenius law; conversion rate of free amino groups changing with reaction temperature at different temperatures. The supporting information is free of charge and available on the ACS Publications website at: http://pubs.acs.org AUTHOR INFORMATION Corresponding Author: Dr. Jing Xu. E-mail: [email protected];

20


Page 20 of 27

Page 21 of 27 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

Author Contributions: The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. ACKNOWLEDGEMENT This work was supported by the National Natural Science Foundation of China (Grant No. 21606138) and Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province. REFERENCES 1. Yan, X.; Cheng, H.; Zare, R. N., Two-phase reactions in microdroplets without the use of phase-transfer catalysts. Angewandte Chemie 2017, 56 (13), 3562-65. 2. Mareček, V.; Samec, Z., Ion transfer kinetics at the interface between two immiscible electrolyte solutions supported on a thick-wall micro-capillary. A mini review. Current Opinion in Electrochemistry 2017, 1 (1), 133-139. 3. Kamyabi, M. A.; Soleymani-Bonoti, F.; Bikas, R.; Hosseini-Monfared, H., Oxygen reduction catalyzed by a Carbohydrazone based compound at liquid/liquid interfaces. Journal of Electroanalytical Chemistry 2017, 794, 235-243. 4. Giustiniani, A.; Drenckhan, W.; Poulard, C., Interfacial tension of reactive, liquid interfaces and its consequences. Advances in Colloid and Interface Science 2017, 247, 185-197. 5. Narayan, S.; Muldoon, J.; Finn, M. G.; Fokin, V. V.; Kolb, H. C.; Sharpless, K. B., "On water": unique reactivity of organic compounds in aqueous suspension. Angewandte Chemie 2005, 44 (21), 3275-9.

21


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

6. Butler, R. N.; Coyne, A. G., Water: nature's reaction enforcer-comparative effects for organic synthesis "in-water" and "on-water". Chemical Reviews 2010, 110 (10), 6302-37. 7. Jönsson, J. B.; Müllner, M.; Piculell, L.; Karlsson, O. J., Emulsion condensation polymerization in dispersed aqueous media. Interfacial reactions and nanoparticle formation. Macromolecules 2013, 46 (22), 9104-113. 8. Qu, Y.; Huang, R.; Qi, W.; Su, R.; He, Z., Interfacial polymerization of dopamine in a pickering emulsion: synthesis of cross-linkable colloidosomes and enzyme immobilization at oil/water interfaces. ACS Applied Materials & Interfaces 2015, 7 (27), 14954-64. 9. Guo, D.; Zhu, D.; Zhou, X.; Zheng, B., Accelerating the "on water" reaction: by organic-water interface or by hydrodynamic effects? Langmuir : the ACS journal of surfaces and colloids 2015, 31 (51), 13759-63. 10. Jung, Y.; Marcus, R. A., On the nature of organic catalysis "on water". Journal of the American Chemical Society 2007, 129 (17), 5492-502. 11. Manna, A.; Kumar, A., Why does water accelerate organic reactions under heterogeneous condition? The Journal of Physical Chemistry. A 2013, 117 (12), 2446-54. 12. Butler, R. N.; Coyne, A. G., Understanding "on-water" catalysis of organic reactions. Effects of H+ and Li+ ions in the aqueous phase and nonreacting competitor H-bond acceptors in the organic phase: on H2O versus on D2O for Huisgen cycloadditions. The Journal of Organic Chemistry 2015, 80 (3), 1809-17.

22


Page 22 of 27

Page 23 of 27 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

13. Mellouli, S.; Bousekkine, L.; Theberge, A. B.; Huck, W. T., Investigation of "on water" conditions using a biphasic fluidic platform. Angewandte Chemie 2012, 51 (32), 7981-4. 14. Tiwari, S.; Kumar, A., Interfacial reactivity of "on water" reactions in the presence of alcoholic cosolvents. The Journal of Physical Chemistry. A 2009, 113 (49), 13685-93. 15. Yu, J. S.; Liu, Y. L.; Tang, J.; Wang, X.; Zhou, J., Highly efficient "on water" catalyst-free nucleophilic addition reactions using difluoroenoxysilanes: dramatic fluorine effects. Angewandte Chemie 2014, 53 (36), 9512-6. 16. Beattie, J. K.; McErlean, C. S.; Phippen, C. B., The mechanism of on-water catalysis. Chemistry 2010, 16 (30), 8972-4. 17. Beare, K. D.; McErlean, C. S., Revitalizing the aromatic aza-Claisen rearrangement: implications for the mechanism of 'on-water' catalysis. Organic & Biomolecular Chemistry 2013, 11 (15), 2452-9. 18. Suen, C. H.; Morawetz, H., Reactive latex studies. 1. Kinetics of reactions of poly(vinylbenzyl chloride) latex with water-soluble amines. Macromolecules 1984, 17 (9), 1800-03. 19. Jimaré, M. T.; Cazaña, F.; Ramirez, A.; Royo, C.; Romeo, E.; Faria, J.; Resasco, D. E.; Monzón, A., Modelling of experimental vanillin hydrodeoxygenation reactions in water/oil emulsions. Effects of mass transport. Catalysis Today 2013, 210, 89-97. 20. Zhu, G.; Wang, P., Polymer-enzyme conjugates can self-assemble at oil/water interfaces and effect interfacial biotransformations. Journal of the American Chemical Society 2004, 126 (36), 11132-3.

23


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

21. Berezkin, A. V.; Kudryavtsev, Y. V., Simulation of end-coupling reactions at a polymer-polymer interface: the mechanism of interfacial roughness development. Macromolecules 2011, 44 (1), 112-21. 22. Trojanek, A.; Marecek, V.; Samec, Z., Temperature effect in the ion transfer kinetics at the micro-interface between two immiscible electrolyte solutions. Electrochim Acta 2015, 180, 366-72. 23. Zhu, C.; Xu, J.; Hou, Z.; Liu, S.; Li, T., Scale effect on the interface reaction between PDMS-E emulsion droplets and gelatin. Langmuir : the ACS journal of surfaces and colloids 2017, 33 (38), 9926-33. 24. Piradashvili, K.; Alexandrino, E. M.; Wurm, F. R.; Landfester, K., Reactions and polymerizations at the liquid-liquid interface. Chemical Reviews 2016, 116 (4), 2141-69. 25. Norde, W.; Gonzalez, F. G.; Haynes, C. A., Protein adsorption on polystyrene latex particles. Polymers for Advanced Technologies 1995, 6 (7), 518-25. 26. Andrade, J. D.; Hlady, V., Protein adsorption and materials biocompatibility: a tutorial review and suggested hypotheses. Biopolymers/Non-Exclusion HPLC 1986, 79 (1), 1-63. 27. Roach, P.; Farrar, D.; Perry, C. C., Interpretation of protein adsorption: surface-induced conformational changes. Journal of the American Chemical Society 1994, 84 (2), 8168-73. 28. Sarobe, J.; MolinaBolívar, J. A.; Forcada, J; Galisteo, F.; HidalgoÁlvarez, R., Functionalized monodisperse particles with chloromethyl groups for the covalent coupling of proteins. Macromolecules 1998, 31 (13), 4282-87.

24


Page 24 of 27

Page 25 of 27 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

29. Norde, W., Driving forces for protein adsorption at solid surfaces. Macromolecular Symposia 2015, 103 (1), 5-18. 30. Schöttler, S.; Becker, G.; Winzen, S.; Steinbach, T.; Mohr, K.; Landfester, K.; Mailänder, V.; Wurm, F. R., Protein adsorption is required for stealth effect of poly(ethylene

glycol)-

and

poly(phosphoester)-coated

nanocarriers.

Nature

Nanotechnology 2016, 11 (4), 372. 31. Gonzalez V.D.G.; Garcia V.S.; Vega J. R.; Marcipar I.S.; Meira G.R.; Gugliotta L. M. Immunodiagnosis of Chagas disease: Synthesis of three latex–protein complexes containing different antigens of Trypanosoma cruzi. Colloids and Surfaces B: Biointerfaces 2010, 77, 12–17. 32. Taniguchi T.; Duracher D.; Delair T.; Elaïssari A.; Pichot C., Adsorption/ desorption behavior and covalent grafting of an antibody onto cationic amino-functionalized poly(styrene-N-isopropylacrylamide) core-shell latex particles. Colloids and Surfaces B: Biointerfaces 2003, 29, 53-65. 33. Besselink G.A.J.; Schasfoort R.B.M.; Bergveld P., Modification of ISFETs with a monolayer of latex beads for specific detection of proteins. Biosensors and Bioelectronics 2003, 18, 1109-14. 34. White S. R.; Sottos N. R.; Geubelle P. H.; Moore J. S.; Kessler M. R.; Sriram S. R.; Brown E. N.; Viswanathan S., Autonomichealing of polymer composites. Nature 2001, 409, 794-97. 35. Mohan D.; Pittman Jr. C. U.; Bricka M.; Smith F.; Yancey B.; Mohammad J.; Steele P. H.; Alexandre-Franco M. F.; Gómez-Serrano V.; Gong H., Sorption of arsenic, cadmium, and lead by chars produced from fast pyrolysis of wood and bark during bio-oil production. Journal of Colloid and Interface Science 2007, 310, 57–73. 25


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 26 of 27

36. López Valdivieso A.; Reyes Bahena J. L.; Song S.; Herrera Urbina R., Temperature effect on the zeta potential and fluoride adsorption at the α-Al 2 O 3 /aqueous solution interface. Journal of Colloid and Interface Science 2006, 298, 1–5. 37. Li, T. D.; Tang, X. L.; Yang, X. D.; Guo, H.; Cui, Y. Z.; Xu, J., Studies on the reaction of allyl glycidyl ether with gelatin by Van Slyke method. Asian Journal of Chemistry 2013, 25 (2), 858-60. 38. Shin, J. M.; Kim, M. P.; Yang, H.; Ku, K. H.; Jang, S. G.; Youm, K. H.; Yi, G. R.; Kim, B. J., Monodipserse nanostructured spheres of block copolymers and nanoparticles via cross-flow membrane emulsification. Chemistry of Materials, 2015, 27 (18), 6314-21. 39.

WilliamMendenhall;

RobertJ.Beaver;

BarbaraM.Beaver,

Introduction

to

probability and statistics = probability and statistics / 11th ed. China Machine Press : 2005. 40. Luo Y. W.; Rui Wang R.; Yang L.; Yu B.; Li B. G.; Zhu S.P., Effect of reversible addition-fragmentation transfer (RAFT) reactions on (Mini)emulsion polymerization kinetics and estimate of RAFT equilibrium constant. Macromolecules 2006, 39, 1328-37. 41. Ma H. Y.; Okuda J., Kinetics and mechanism of L-Lactide polymerization by rare earth metal silylamido complexes: effect of alcohol addition. Macromolecules 2005, 38, 2665-73. 42. Storey R. F.; Sherman J. W., Kinetics and mechanism of the stannous octoate-catalyzed bulk polymerization of ɛ-caprolactone. Macromolecules 2002, 35, 1504-12.

26


Page 27 of 27 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

33x25mm (600 x 600 DPI)


Reaction Kinetics at PDMS-E Emulsion Droplets-Gelatin Interface

Recommend Documents