A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), Vavilova St. 28, Moscow 119991, Russia.
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences (INEOS RAS), Vavilova St. 28, Moscow 119991, Russia.
Int J Biol Macromol. 2022 Aug 1;214:192-202. doi: 10.1016/j.ijbiomac.2022.06.059. Epub 2022 Jun 14.
In this work, the interaction between the negatively charged surfactant sodium dodecyl sulfate (SDS) and partially N-reacetylated chitosan (RA-CHI), which is soluble at pH range up to pH 12, is studied in a wide pH range including alkaline media by light scattering (LS) and isothermic titration calorimetry (ITC). It is shown that in the weakly alkaline medium (pH 7.4), RA-CHI/SDS interaction is exothermic and cooperative. This interaction is found to be coupled with proton transfer from the buffer substance to chitosan as it is revealed by the dependence of the measured heat release on the ionization enthalpy of the buffer. At higher pH values (pH > 8), another mechanism of interaction is observed that include SDS micellization induced by hydrophobic interactions with polymer segments, so that no phase separation occurred in these mixtures. The results obtained can contribute to expand the knowledge about application of chitosan for preparation of pharmaceutical and cosmetic compositions containing anionic surfactants.
在这项工作中，通过光散射（LS）和等温热滴定（ITC）研究了在很宽的 pH 范围内，包括碱性介质，带负电荷的表面活性剂十二烷基硫酸钠（SDS）与部分 N-乙酰化壳聚糖（RA-CHI）之间的相互作用，RA-CHI 在 pH 范围高达 12 时可溶于该体系。结果表明，在弱碱性介质（pH 7.4）中，RA-CHI/SDS 的相互作用是放热和协同的。通过测量的热量释放与缓冲物质的离解焓的关系，发现这种相互作用与质子从缓冲物质向壳聚糖的转移有关。在更高的 pH 值（pH>8）下，观察到另一种相互作用机制，包括 SDS 通过与聚合物链段的疏水相互作用诱导胶束化，因此这些混合物中没有发生相分离。所获得的结果有助于扩展关于壳聚糖在制备含有阴离子表面活性剂的药物和化妆品组合物中的应用的知识。
