通过低场 NMR 对温敏性壳聚糖/β-甘油磷酸盐水凝胶溶胶-凝胶转变温度的在线监测。

On-line monitoring of the sol-gel transition temperature of thermosensitive chitosan/β-glycerophosphate hydrogels by low field NMR.

机构信息

State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.

State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.

出版信息

Carbohydr Polym. 2020 Jun 15;238:116196. doi: 10.1016/j.carbpol.2020.116196. Epub 2020 Mar 20.

DOI:10.1016/j.carbpol.2020.116196

PMID:32299576

Abstract

A temperature controlled low field nuclear magnetic resonance (LF-NMR) T relaxometry technique based on the mobility changes of water trapped in hydrogels, was successfully used for on-line determination of the sol-gel transition temperature for chitosan/β-glycerophosphate (CS/GP) hydrogels in real time. The LF-NMR results indicated that the gelation temperature decreased gradually with increasing GP concentration, and the results were supported by both thermogravimetric differential scanning calorimetry (DSC) and rheological findings; however, LF-NMR allows non-destructive monitoring of samples during continuous heating. Moreover, as the mobility of water molecules varies greatly during the sol-gel phase transition, the LF-NMR measurement was more sensitive and accurate (RSD ≤ 0.1 %, n = 5) compared with DSC (RSD: 1.2 %-3.7 %, n = 5) and rheology (RSD: 1.1 %-2.3 %, n = 5).

摘要

基于水在水凝胶中迁移率变化的温度控制的低场核磁共振（LF-NMR）弛豫技术，成功地用于实时在线测定壳聚糖/β-甘油磷酸（CS/GP）水凝胶的溶胶-凝胶转变温度。LF-NMR 结果表明，随着 GP 浓度的增加，凝胶化温度逐渐降低，热重差示扫描量热法（DSC）和流变学研究结果也支持这一结果；然而，LF-NMR 允许在连续加热过程中对样品进行无损监测。此外，由于水分子在溶胶-凝胶相变过程中的迁移率变化很大，因此 LF-NMR 测量比 DSC（RSD：1.2%-3.7%，n=5）和流变学（RSD：1.1%-2.3%，n=5）更灵敏和准确（RSD≤0.1%，n=5）。