Smart Assembly Behaviors of Hydroxypropylcellulose-graft-poly(4-vinyl pyridine) Copolymers in Aqueous Solution by Thermo and pH Stimuli
作者：Lin Ma, Hongliang Kang, Ruigang Liu*, and Yong Huang*
關鍵字：hydroxypropylcellulose, graft copolymer, multi-stimuli responsive, micelle
論文來源：期刊
具體來源：Langmuir, 2010, 26 (23), pp 18519–18525
發表時間：2010年
Thermo- and pH-sensitive graft copolymers, hydroxypropylcellulose-graft-poly(4-vinyl pyridine) (HPC-g-P4VP), were synthesized via atom transfer radical polymerization (ATRP) and characterized. The thermo- and pH-induced micellization and stimuli-responsive properties of HPC-g-P4VP graft copolymers in aqueous solution were investigated by transmittance, 1H NMR, dynamic light scattering (DLS), and so on. For the pH-induced micellization, the P4VP side chains collapse to form the core of the micelles, and the HPC backbones stay in the shell to stabilize the micelles. In the case of thermoinduced micellization, the HPC backbones collapse to form the core of the micelles that was stabilized by the P4VP side chains in the shell upon heating. What’s more, the cloud point of the HPC-g-P4VP copolymers in the aqueous solution could be finely tuned by changing the length of P4VP side chains or the pH values. In acidic water, the longer the side chains, the higher the cloud point. For those HPC-g-P4VP copolymers with short side chains, for example, HPC0.05-g-P4VP3, the lower pH correlates a higher cloud point. The thermo- or pH-induced micelles also have the pH- or thermosensitivity due to their P4VP or HPC shells.