Rheological properties of hydrogels composed of TEMPO-oxidised cellulose nanofibrils (OCNF)-starch in the presence of cationic surfactants were investigated. The cationic surfactants dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB) were used to trigger gelation of OCNF at around 5 mM surfactant. As OCNF and DTAB/CTAB are oppositely charged, an electrostatic attraction is suggested to explain the gelation mechanism. OCNF (1 wt%) and soluble starch (0.5 and 1 wt%) were blended to prepare hydrogels, where the addition of starch to the OCNF resulted in a higher storage modulus. Starch polymers were suggested to form networks with cellulose nanofibrils. The stiffness and viscosity of OCNF-Starch hydrogels were enhanced further by the addition of cationic surfactants (5 mM of DTAB/CTAB). ζ -potential and amylose-iodine complex analyses were also conducted to confirm surface charge and interaction of OCNF-starch-surfactant in order to provide an in-depth understanding of the surfactant-induced gel networks.

中文翻译：

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阳离子表面活性剂作为氧化纤维素纳米原纤维和淀粉基水凝胶的非共价接头。

研究了在阳离子表面活性剂存在下由TEMPO氧化纤维素纳米原纤维（OCNF）-淀粉组成的水凝胶的流变特性。阳离子表面活性剂十二烷基三甲基溴化铵（DTAB）和十六烷基三甲基溴化铵（CTAB）用于引发约5 mM表面活性剂的OCNF胶凝。由于OCNF和DTAB / CTAB带相反的电荷，建议使用静电吸引来解释凝胶化机理。将OCNF（1 wt％）和可溶性淀粉（0.5和1 wt％）混合以制备水凝胶，其中将淀粉添加到OCNF中会导致更高的储能模量。建议淀粉聚合物与纤维素纳米原纤维形成网络。加入阳离子表面活性剂（5 mM DTAB / CTAB）可进一步提高OCNF-淀粉水凝胶的刚度和粘度。