Reaction Kinetics at PDMS-E Emulsion Droplet–Gelatin Interface

Abstract

In this work, interfacial reaction kinetics between α-[3-(2,3-epoxypropoxy)­propyl]-ω-butyl-polydimethylsiloxane 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 (k 2) was obtained by using the 2nd-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.

Adsorption–Reaction Processes Between Gelatin and PDMS-E Emulsion Droplets

“…8−12 We had studied the preparation of monodisperse emulsion droplet of α-[3-(2,3-epoxypropoxy) propyl]-ω-butylpolydimethylsiloxane (PDMS-E) and investigated the influence of the size of PDMS-E droplet on the interfacial chemical reaction with gelatin. 13,14 During these study, we found that the adsorption of gelatin onto the surface of the PDMS-E droplet may be an important factor affecting the interfacial chemical reactions.…”

“…In the heterogeneous reaction system of polymers, the preparation of monodisperse latex particles with uniform size does not only enable reactions with increased efficiency and under milder reaction conditions − but also avoids the influence of confinement effect caused by the change of particle size on its structure, so that the overall structure and properties can be successfully reproduced repeatedly . Therefore, the preparation and surface chemical modification of monodisperse emulsion particles has become a hot spot in the research of oil–water interface chemical reactions during the recent years. − We had studied the preparation of monodisperse emulsion droplet of α-[3-(2,3-epoxypropoxy) propyl]-ω-butyl-polydimethylsiloxane (PDMS-E) and investigated the influence of the size of PDMS-E droplet on the interfacial chemical reaction with gelatin. , During these study, we found that the adsorption of gelatin onto the surface of the PDMS-E droplet may be an important factor affecting the interfacial chemical reactions.…”

“…The above research indicated that surface curvature closely depends on the size of monodispersed emulsion particles. Our previous study suggested that charge density and functional group exposure were determined by the size of emulsion droplets. , Hence, it can be deduced that if the size of the monodispersed emulsion particles is adjusted up to a sufficient scale, the adsorption patterns of protein can be efficiently tuned. Further, the extension of the protein chain can be regulated, which can cast a profound effect on the chemical reaction.…”