This work deals with the interactions among cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) with α-chymotrypsin (α-CT) and trypsin in aqueous medium on pH 7.75 by conductivity and surface tension measurements. The critical micelle concentrations (CMC), surface parameters i.e., the maximum surface excess concentration (Γ_max), minimum area per surfactant molecule (A_min), the surface pressure at CMC (π_CMC) and thermodynamic parameters i.e., degree of ionization (α), Gibbs free energy of micellization (ΔG°_m), the standard Gibbs energy of adsorption (ΔG°_ads)_, the free energy at air-water interface (ΔG^s_mim) have been evaluated. The CMC has increased and surface tension of CMC (γ_CMC) values have decreased (at maximum μL of α-CT and trypsin), significantly in the presence of different μL of the added α-CT and trypsin. In this study, ΔG⁰_ads value is established to be greater than ΔG⁰_m, showing that adsorption is more favored in aqueous surfactants systems. Thermodynamic parameters show that enzyme-CTAB/SDS monomeric aggregation started to form micelles at a higher concentration of surfactant to compare with the CMC of pure CTAB/SDS micelles. It is significant that increasing the μL of α-CT and trypsin results in an increase in the spontaneity CMC on surfactants, α-CT and trypsin have more affinity for SDS compared to CTAB.

中文翻译：

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α-胰凝乳蛋白酶和胰蛋白酶的表面活性剂的界面和热力学方法：对比研究

通过电导率和表面张力测量，研究了十六烷基三甲基溴化铵（CTAB），十二烷基硫酸钠（SDS）与α-胰凝乳蛋白酶（α-CT）和胰蛋白酶在水性介质中在pH 7.75下的相互作用。临界胶束浓度（CMC），表面参数即，最大表面过量浓度（Γ_最大），每个表面活性剂分子（最小面积甲_分钟）中，在CMC（表面压力π _CMC）和热力学参数，即，离子化的程度（ α），胶束化的吉布斯自由能（ΔG° _m），吸附的标准吉布斯能（ΔG° _ads）_，在空气-水界面（ΔG的自由能^小号_MIM）已被评估。在添加了不同μL的α-CT和胰蛋白酶的情况下，CMC有所增加，而CMC的表面张力（_γCMC）值降低了（在最大μL的α-CT和胰蛋白酶下）。在这项研究中，ΔG ⁰_广告值设置为比ΔG大于⁰_中号，表明在水性表面活性剂体系中吸附更受青睐。热力学参数表明，与纯CTAB / SDS胶束的CMC相比，酶-CTAB / SDS单体聚集体开始在较高的表面活性剂浓度下形成胶束。重要的是，增加α-CT和胰蛋白酶的μL会导致表面活性剂的自发性CMC升高，与CTAB相比，α-CT和胰蛋白酶对SDS的亲和力更大。