Monodisperse and fast-responsive poly(N-isopropylacrylamide) microgels with open-celled porous structure.
A simple and efficient method is developed to fabricate monodisperse and fast-responsive poly(N-isopropylacrylamide) (PNIPAM) microgels with open-celled porous structure. First, numerous fine oil droplets are fabricated by homogeneous emulsification method and are then evenly dispersed inside monodisperse PNIPAM microgels as porogens via the combination of microfluidic emulsification and UV-initiated polymerization methods. Subsequently, the embedded fine oil droplets inside the PNIPAM microgels are squeezed out upon stimuli-induced rapid volume shrinkage of the microgels; as a result, a spongelike open-celled porous structure is formed inside the PNIPAM microgels. The open-celled porous structure provides numerous interconnected free channels for the water transferring convectively inward or outward during the volume phase transition process of PNIPAM microgels; therefore, the response rates of the PNIPAM microgels with open-celled porous structure are much faster than that of the normal ones in both thermo-responsive shrinking and swelling processes. Because of the fast-responsive characteristics, the microgels with open-celled porous structure will provide ever better performances in their myriad applications, such as microsensors, microactuators, microvalves, and so on.
School of Chemical Engineering, Sichuan University , Chengdu, Sichuan 610065, P. R. China.
Chuan-Lin
CL
Mou
Xiao-Jie
XJ
Ju
Lei
L
Zhang
Rui
R
Xie
Wei
W
Wang
Nan-Nan
NN
Deng
Jie
J
Wei
Qianming
Q
Chen
Liang-Yin
LY
Chu
D000180:Acrylic Resins / Q000737:chemistry*; D004655:Emulsions; D005782:Gels; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D013696:Temperature; D013997:Time Factors
D000180:Acrylic Resins; D004655:Emulsions; D005782:Gels; C052970:poly-N-isopropylacrylamide