pH and Temperature-sensitive Behaviors of Poly(4-vinyl pyridine-co-N-isopropyl acrylamide) Microgels

Abstract

ABSTRACT:Poly(4VP-co-NIPAM) microgels were prepared from 4-vinyl pyridine (4VP) and N-isopropyl acrylamide (NIPAM) with methylene-bis-acrylamide (MBAm) as a cross-linking agent using partially quarternized poly(4-vinyl pyridine) as emulsifier, which is a special emulsion polymerization method.The morphology and hydrodynamic diameter of the microgel particles were characterized by TEM and photon correlation spectroscopy (PCS). The dependence of pH and temperature of the copolymer microgel particles were investigated and the influence of the KCl concentration in the microgel dispersion was observed.Hydrodynamic diameters of the microgel particles were drastically increased below pH 5 and those of the microgel particles were depended on temperature and KCl concentration in the microgel dispersion. The dependence of pH and temperature on the microgel particles were affected by molar ratio of 4VP/NIPAM. The cross-linked copolymer microgels composed of 4VP/NIPAM ratio of 1/9, exhibited broad shrinking transition. The swelling behavior for the microgel dispersion was much sensitive to the KCl concentration in the microgel dispersion at elevated temperature. [DOI 10.1295/polymj.37.565] KEY WORDS Emulsion Polymerization / Poly(4VP-co-NIPAM) Microgels / pH/Temperaturesensitive Microgels / Swelling/Deswelling Behavior / Colloidal Particles / Polymer hydrogels and microgels have a wide range of potential application in biotechnology and biomedical field. Therefore, various polymer hydrogels and microgels have been characterized where the volume change can be induced by pH, temperature, ionic strength, and electric field of the polymer matrix.

Preparation of Amphiphilic Polysilsesquioxane by Grafting of Block Copolymer of Acrylamide Monomers

“…The investigations concerning the later property caused by polymerized NIPAM (polyNIPAM) have been widely developed and various applications are proposed such as microencapsulation, biosensor, and drug delivery. [21][22][23][24][25] Such facts support the expectation that the polysilsesquioxane, combined the inorganic polysiloxane backbone with the thermoresponsive and amphiphilic graft chains, will be a candidate for high performance hybrid materials. [26][27][28] Our previous grafting was conducted through free radical polymerization by the use of mercapto groups on the polysilsesquioxane backbone.…”

Synthesis of thermoresponsive polysilsesquioxane with methoxyethylamide group and crown ether

“…This property is required of materials used for microencapsulation, biosensors, drug delivery and so forth, as reported in a variety of recent works. [17][18][19][20][21][22][23] Owing to the interest in such applications, we have investigated the graft polymerization of N-isopropylacrylamide. [24][25][26] Through the grafting of the polymeric component, the resulting PSQ successfully exhibited a thermoresponsive property in an aqueous solution.…”

Dispersion polymerization of styrene employing lyophilic comonomer in the absence of stabilizer: Synthesis of impurity-free microspheres

“…12-15 Especially, polymeric microspheres containing the pyridine group are currently utilized in the preparation of metal oxide-containing hybrid particles for electrophoretic ink, 16 pH and temperature responsive particles, 17 support for catalysts, 18 fabrication of electroluminescence devices, 19 and the formation of core/inorganic shell structure. 20 However, the synthesis of microspheres of styrene *Corresponding Author.…”