title: Single-chain polymers achieved from radical polymerization under single-initiator conditions.
abstract: Radical polymerization from a single initiator molecule in a microenvironment is a nearly ideal system in which bimolecular termination, solution concentration, and viscosity changes could be neglected. In this study, we provide two facile methods of preparing polymers via atom-transfer radical polymerization (ATRP) under single-initiator conditions: tether initiators on planar substrates at superlow density through mixed self-assembled monolayers (SAMs) and encapsulated single initiators in microfluidic droplets. The molecular weight (MW) of the resultant polymers characterized by atomic force microscope-based single-molecule force spectroscopy (AFM-based SMFS) showed that the single-chain ATRP had an extraordinarily faster chain propagation rate (2 unit/s) on planar substrates and gave polymers with much higher MWs (10(5)-10(6) g/mol) than those obtained from traditional ATRP (10(3)-10(5) g/mol). The former method offered a general platform for single-chain polymer synthesis and investigation, and the latter could be amplified to obtain abundant single-chain polymers with ultrahigh molecular weight (UHMW) for commercial applications.
authors.affiliation: Division of Nanobiomedicine, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou 215123, PR China.
authors.forename: Shen
authors.initials: S
authors.lastname: Zhang
authors.forename: Xiangchao
authors.initials: X
authors.lastname: Pang
authors.forename: Dameng
authors.initials: D
authors.lastname: Guo
authors.forename: Bo
authors.initials: B
authors.lastname: Zheng
authors.forename: Shuxun
authors.initials: S
authors.lastname: Cui
authors.forename: Hongwei
authors.initials: H
authors.lastname: Ma
mesh_terms: D005609:Free Radicals / Q000138:chemical synthesis / Q000737:chemistry; D008970:Molecular Weight; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties
chemical_list: D005609:Free Radicals; D011108:Polymers