壳聚糖-京尼平纳米凝胶体系交联动力学与应用  

Crosslinking Kinetics and Application of Chitosan-Genipin Nanogel

作　　者：赵欣悦 李培通 刘砚华 胡冰[3] 刘勇刚[1] 陈全[1,2] Xin-yue Zhao;Pei-tong Li;Yan-hua Liu;Bing Hu;Yong-gang Liu;Quan Chen(State Kay Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022;School of Applied Chemistry and Engineering,Univerdity of Science and Technology of China,Hefei 230026;College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095)

机构地区：[1]中国科学院长春应用化学研究所高分子物理与化学国家重点实验室,长春130022 [2]中国科学技术大学应用化学与工程学院,合肥230026 [3]南京农业大学食品科技学院,南京210095

出　　处：《高分子学报》2024年第3期275-286,共12页Acta Polymerica Sinica

基　　金：国家重点研发计划“政府间国际科技创新合作”重点专项(项目号2018YFE0121400)资助.

摘　　要：天然交联剂京尼平交联壳聚糖稀溶液可得到具有生物相容性的纳米凝胶.利用非对称流场流分离(AF4)对该纳米凝胶交联过程中的尺寸分布及结构演化进行系统研究,发现纳米凝胶分子量分布很宽,跨越3个数量级,但尺寸分布较窄.为探究该规律的普适性,系统研究了预聚物链的分子量以及交联剂浓度对于凝胶行为的影响.发现:(1)不同分子量预聚物得到的纳米凝胶具有相似的尺寸与分子量分布特征,其中相同分子量产物的特征尺寸会随着预聚物分子量的降低而减小,这一现象是由于达到相同尺寸时,低分子量预聚物形成凝胶支化程度更高造成的,这一结论也进一步通过分析比较反应程度与链内密度得到证实;(2)随着交联浓度的提高,凝胶特征尺寸先逐渐降低再逐渐升高.这是由于京尼平具有2个交联位点,交联分两步进行,尺寸降低是由于链内交联密度增加造成纳米凝胶网络结构塌缩,后续尺寸升高是由于第一步交联过度后,反而不利于第二步交联的进行;(3)制备的壳聚糖-京尼平纳米凝胶由于其尺寸的均一性和亲疏水平衡性,可作高效乳化剂制备Pickering乳液:仅需要0.57wt%的壳聚糖纳米凝胶就可以制备稳定的含油量可高达90%的Pickering乳液.The natural crosslinking agent genipin can crosslink chitosan in a dilute solution to obtain biocompatible nanogel particles.The particles can be used as the emulsifier of Pickering emulsion.This study examines the conformation and structural evolutions using asymmetric flow field-flow fractionation(AF4)combined with multiple detectors.The nanogel particles show an extremely wide molecular weight distribution but a much narrower size distribution.To explore the universality of this behavior,we adjusted the molecular weight of the prepolymer chain and the crosslinker concentration,respectively.The nanogels obtained from prepolymers with different molecular weights exhibit similar molecular weight and size distributions,but the characteristic size decreases with decreasing M of the prepolymers.This latter trend is due to the higher crosslinking density and accordingly the higher internal density for the nanogel based on prepolymer of the lower M.For a given prepolymer,the characteristic size first decreases and then increases with the crosslinker concentration.The former decrease is caused by the enhancement of intrachain crosslinking,whereas the later increase is attributable to the excessive crosslinkers that attach to the polymer chain as dangling molecules,which suppresses the further intra-or interchain crosslinking reaction.Finally,the nanogel particles obtained in this study turn out to be an efficient emulsifier in preparing high internal phase emulsion due to its uniform size,high specific surface area and balance between hydrophilicity and lipophilicity:a Pickering emulsion with oil content of up to 90%can be stabilized using only 0.57 wt%of the nanogel particles.

关 键 词：壳聚糖 京尼平 交联 纳米凝胶 场流分离 高内相乳液 

分 类 号：TQ427.26[化学工程] TB383.1[一般工业技术—材料科学与工程]