文献类型：期刊文献

英文题名：Modulating living crystallization-driven self-assembly behaviors of oligo(p-phenylene ethynylene)-containing block copolymers and micellar stability by solvent and corona-forming chain length

作者：Nie, Jiucheng[2,3];Xia, Longgang[1];Huang, Xiaoyu[2,3];Lu, Guolin[2];Feng, Chun[1,2]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Univ Chinese Acad Sci, Chinese Acad Sci, Shanghai Inst Organ Chem, Key Lab Synthet & Selfassembly Chem Organ Funct Mo, 345 Lingling Rd, Shanghai 200032, Peoples R China;[3]ShanghaiTech Univ, Sch Phys Sci & Technol, 100 Haike Rd, Shanghai 201210, Peoples R China

年份：2023

卷号：14

期号：25

起止页码：2987

外文期刊名：POLYMER CHEMISTRY

收录：;EI(收录号：20232414229437);WOS:【SCI-EXPANDED(收录号:WOS:000999734800001)】；

基金：The authors are thankful for financial support from the National Science Foundation for Distinguished Young Scholars (51825304), the National Natural Science Foundation of China (52122314 and U22A20131), the project of the Bureau of International Cooperation, CAS (121731KYSB20200006), the Shanghai Scientific and Technological Innovation Project (20JC1415400, 21520780100 and 22ZR1475400), the Innovation Program of Shanghai Municipal Education Commission (2019-01-07-00-05-E00012) and the East China University of Science and Technology (SLD13223004). The authors thank Dr Kun Cui for his assistance in TEM measurements and the beamline BL16B1 at SSRF for providing the beam time.

语种：英文

外文关键词：Acrylic monomers - Amides - Aromatic compounds - Block copolymers - Chain length - Elongation - Kinetics - Nucleation - Self assembly - Solvents - Stability

摘要：Living crystallization-driven self-assembly with separated nucleation and growth stages enables the formation of uniform fiber-like micelles with precise length/composition. The kinetic stability of formed micelles in the whole micellar elongation process is one of the most important prerequisites to realize the living characteristic of CDSA, while reports on systematic investigations on structural and experimental effects on the kinetic stability of micelles are rare. Herein, we synthesize a series of OPE7-based block copolymers (OPE7-b-PNIPAM(8), OPE7-b-PNIPAM(22) and OPE7-b-PNIPAM(47), OPE = oligo(p-phenylene ethynylene), PNIPAM = poly(N-isopropylacrylamide), and the subscripts represent the polymerization degree of each block), consisting of the same crystalline core-forming OPE7 block, but different corona-forming PNIPAM segments of varying chain lengths. These BCPs are used as a model to probe the influence of the PNIPAM chain length and solvent on the kinetic stability of micelles and CDSA behaviors. We found that the initially formed micelles and seed micelles can be kinetically frozen with the decrease in PNIPAM chain length or the solubility of BCPs upon adding water. Interestingly, it was found that OPE7-b-PNIPAM(8) followed an atypical micellar elongation mechanism in the self-seeding process in ethanol/water (v/v = 90/10). The diamond-like seed micelles followed an end-to-end coupling manner along the regions of acute angles of micelles to form necklace-like micelles with annealing temperatures from 35 degrees C to 60 degrees C, while ribbon-like micelles were formed at 70 degrees C. Both OPE7-b-PNIPAM(22) and OPE7-b-PNIPAM(47) obey typical micellar elongation mechanisms in the self-seeding process to give uniform fiber-like micelles of controlled length under similar conditions. In addition, the resistance of OPE7-b-PNIPAM(22) seed micelles toward dissolution upon heating increased with the decrease in PNIPAM chain length and the increase in solvent polarity. In particular, the resistance of seed micelles, a key parameter in determining self-seeding behaviors, can be evaluated by the difference in Hansen solubility parameters between BCPs and solvents.