Faculty of Biotechnology and Food Engineering, Technion, Haifa, Israel.
Department of Food Engineering, University of Guelph, Guelph, Canada.
Carbohydr Polym. 2015;127:355-62. doi: 10.1016/j.carbpol.2015.03.085. Epub 2015 Apr 13.
The effects of surfactant addition to ethyl-cellulose (EC) based oleogels were examined with respect to the chemical nature of the "head" and "tail" groups of the surfactant. Unique sigmoidal temperature dependent rheological behavior was observed upon surfactant addition, suggesting additional organized structure formation. Glycerol-based surfactant addition lead to greatest decrease in the sol-gel and gel-sol transition temperatures compared to sorbitan-based surfactants. This behavior can be attributed to the plasticizing nature of the small head group of glycerol compared to the larger head group of sorbitan surfactants. A significant increase in the penetration force of the gels was observed upon surfactant addition, suggesting possible surfactant-polymer interactions which stiffen the polymer network. Thermal analysis detected a reduction in both SMS and GMS crystallization peak temperature and enthalpy. In the case of GMS, two melting peaks were observed upon EC addition to the oil phase, suggesting EC/surfactant interactions. These results demonstrate the effects of surfactant head group structure on EC oleogel rheological properties.
考察了表面活性剂添加到乙基纤维素（EC）基油凝胶中对表面活性剂“头”和“尾”基团化学性质的影响。添加表面活性剂后，观察到独特的类正弦温度依赖流变行为，表明形成了额外的有序结构。与山梨坦基表面活性剂相比，基于甘油的表面活性剂的添加导致溶胶-凝胶和凝胶-溶胶转变温度的最大降低。这种行为可以归因于甘油的小头基团相对于山梨坦表面活性剂的较大头基团的增塑性质。添加表面活性剂后，凝胶的穿透力显著增加，表明可能存在表面活性剂-聚合物相互作用，从而使聚合物网络变硬。热分析检测到 SMS 和 GMS 结晶峰温度和焓的降低。对于 GMS，在向油相添加 EC 后观察到两个熔融峰，表明 EC/表面活性剂相互作用。这些结果表明了表面活性剂头基结构对 EC 油凝胶流变性质的影响。
