title: Effects of polar group saturation on physical gelation of amphiphilic polymer solutions.
abstract: Monte Carlo simulation on the basis of the comblike coarse grained nonpolar/polar (NP) model has been carried out to study the polar group saturation effect on physical gelation of amphiphilic polymer solutions. The effects of polar group saturation due to hydrogen bonding or ion bridging on the sol-gel phase diagram, microstructure of aggregates, and chain conformation of amphiphilic polymer solutions under four different solvent conditions to either the nonpolar backbone or the polar side chain in amphiphilic polymer chains have been investigated. It is found that an increase of polar group saturation results in a monotonically decreased critical concentration of gelation point, which can be qualitatively supported by the dynamic rheological measurements on pectin aqueous solutions. Furthermore, various solvent conditions to either the backbone or the side chain have significant impact on both chain conformation and microstructure of aggregates. When the solvent is repulsive to the nonpolar backbone but attractive to the polar side chain, the polymer chains are collapsed, and the gelation follows the mechanism of colloidal packing; at the other solvent conditions, the gelation follows the mechanism of random aggregation.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
authors.forename: Yunqi
authors.initials: Y
authors.lastname: Li
authors.forename: Tongfei
authors.initials: T
authors.lastname: Shi
authors.forename: Lijia
authors.initials: L
authors.lastname: An
authors.forename: Jooyoung
authors.initials: J
authors.lastname: Lee
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wang
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Huang
mesh_terms: D005782:Gels / Q000737:chemistry*; D008956:Models, Chemical; D009010:Monte Carlo Method; D010368:Pectins / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012212:Rheology / Q000379:methods; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D005782:Gels; D011108:Polymers; D012996:Solutions; D013501:Surface-Active Agents; D010368:Pectins