Measuring microgel swell ratio by cryo-SEM

POLYMER

卷:116

Article

Liang, Jing¹  Teng, Feiyue¹  Chou, Tseng-Ming^1,2  Libera, Matthew¹ 

[1] Stevens Inst Technol, Dept Chem Engn & Mat Sci, Hoboken, NJ 07030 USA

[2] Stevens Inst Technol, Lab Multiscale Imaging, Hoboken, NJ 07030 USA

关键词: Microgel;    Swell ratio;    Cryo-SEM;   

DOI  :  10.1016/j.polymer.2017.03.050

来源: Elsevier

【 摘 要 】

The swell ratio is a key parameter characterizing the structure and properties of a hydrogel. In macroscopic gels, the swell ratio can be determined by straightforward measurements of the gel weight in the dry and hydrated states. However, measuring the swell ratio characteristic of microgels (gel particles with dimensions of 0.1-100 mu m) is substantially more challenging because of their small size and polydispersity. We use cryo-scanning electron microscopy (cryo-SEM) to measure microgel diameter both in the frozen-hydrated and fully dry states using pH-responsive poly(ethylene glycol)-co-acrylic acid microgels. The volume swell ratios characteristic of the various microgels are essentially the same as those measured from otherwise-identical macroscopic gels. Hence we can conclude that, at least in this case where the macroscopic gel and microgel synthesis methods are similar, the simple measurement of a macroscopic swell ratio provides a reasonable approximation to the microgel swell ratio. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free