Xu Qingyi, Nakajima Mitsutoshi, Ichikawa Sosaku, Nakamura Nobutaka, Roy Poritosh, Okadome Hiroshi, Shiina Takeo
Food Engineering Division, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
J Colloid Interface Sci. 2009 Apr 1;332(1):208-14. doi: 10.1016/j.jcis.2008.12.044. Epub 2008 Dec 24.
As interest in the application of microbubbles grows, it is becoming increasingly important to understand the factors affecting their formation and properties in order to effectively generate microbubbles. This paper investigates the effect of surfactant concentration and electrolyte addition on the size distribution and stability of microbubbles. The anionic surfactant sodium dodecyl sulfate (SDS) was used as the surfactant. Minimum bubble diameter and maximum stability were achieved at surfactant concentrations above the CMC. The effect of the electrolyte addition was studied by adding sodium chloride (NaCl) at an SDS concentration below the critical micelle concentration (CMC). Addition of NaCl decreased bubble size and improved bubble preparation to a certain extent. The addition of salt at low concentrations did not affect the surface tension; however, the surface tension was reduced as salt concentration was increased and reached a constant value for NaCl concentrations above 0.25%. The presence of NaCl resulted in a significant decrease in zeta-potential, implying a reduction in the surface charge of SDS micelles. This result suggests that the presence of NaCl may improve the generation and stability of bubbles by enhancing the structures of the adsorption monolayer and interfacial film.
随着对微泡应用的兴趣日益增长，为了有效地产生微泡，了解影响其形成和性质的因素变得越来越重要。本文研究了表面活性剂浓度和添加电解质对微泡尺寸分布和稳定性的影响。使用阴离子表面活性剂十二烷基硫酸钠（SDS）作为表面活性剂。在表面活性剂浓度高于临界胶束浓度（CMC）时，可实现最小气泡直径和最大稳定性。通过在低于临界胶束浓度（CMC）的SDS浓度下添加氯化钠（NaCl）来研究添加电解质的影响。添加NaCl会减小气泡尺寸，并在一定程度上改善气泡制备。低浓度盐的添加不会影响表面张力；然而，随着盐浓度的增加，表面张力会降低，并且当NaCl浓度高于0.25%时达到恒定值。NaCl的存在导致ζ电位显著降低，这意味着SDS胶束的表面电荷减少。该结果表明，NaCl的存在可能通过增强吸附单层和界面膜的结构来改善气泡的产生和稳定性。
