Departmento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
J Chromatogr A. 2009 Nov 27;1216(48):8528-34. doi: 10.1016/j.chroma.2009.09.077. Epub 2009 Oct 2.
The effect of Hodag CB6, a widely used non-ionic surfactant in sugar crystallization process, on the surface properties of sucrose was studied in detail by inverse gas chromatography (IGC) experiments. IGC experiments were performed with pure sucrose crystals, surfactant coated sucrose crystals, and crystals grown in the presence of surfactant at 313.05 and 323.05 K. The surfactant promotes the specific interactions with the polar probes. The sorption of basic, acidic and amphoteric probes onto pure and surfactant coated sucrose was found to be endothermic and in the case of neutral probes was found to be exothermic. The surfactant increases both the acidity and basicity of the sucrose surface with the latter effect being significant. The role of interfacial tension on the growth kinetics of sucrose crystals was studied using IGC for different surfactant concentrations. IGC results with the surfactant coated sucrose were used to interpret the thermodynamic effect of surfactants during the crystal growth process. The dispersive component of the surface energy, gamma(s)(D), of surfactant coated sucrose crystals was found to be lower than that of pure sucrose crystals and was found to be in the range of 33.49-35.27 mJ/m(2).
通过反气相色谱（IGC）实验详细研究了在糖结晶过程中广泛使用的非离子表面活性剂 Hodag CB6 对蔗糖表面性质的影响。IGC 实验在 313.05 和 323.05 K 下用纯蔗糖晶体、表面活性剂涂覆的蔗糖晶体和存在表面活性剂时生长的晶体进行。表面活性剂促进与极性探针的特定相互作用。发现碱性、酸性和两性探针对纯蔗糖和表面活性剂涂覆的蔗糖的吸附是吸热的，而中性探针的吸附是放热的。表面活性剂增加了蔗糖表面的酸度和碱度，后者的影响更为显著。使用 IGC 研究了不同表面活性剂浓度下界面张力对蔗糖晶体生长动力学的影响。使用涂有表面活性剂的蔗糖的 IGC 结果用于解释表面活性剂在晶体生长过程中的热力学效应。发现表面活性剂涂覆的蔗糖晶体的分散表面能分量 γ(s)(D)低于纯蔗糖晶体，并且在 33.49-35.27 mJ/m² 的范围内。
