Chanwattanakit Jarussri, Chavadej Sumaeth
The Petroleum and Petrochemical College, Chulalongkorn University.
Center of Excellence on Petrochemical and Materials Technology.
J Oleo Sci. 2018 Feb 1;67(2):187-198. doi: 10.5650/jos.ess17135. Epub 2018 Jan 23.
Laundry detergency of solid non-particulate soil on polyester and cotton was investigated using a microemulsion-based formulation, consisting of an anionic extended surfactant (C-4PO-SONa) and sodium mono-and di-methyl naphthalene sulfonate (SMDNS) as the hydrophilic linker, to provide a Winsor Type III microemulsion with an ultralow interfacial tension (IFT). In this work, methyl palmitate (palmitic acid methyl ester) having a melting point around 30°C, was used as a model solid non-particulate (waxy) soil. A total surfactant concentration of 0.35 wt% of the selected formulation (4:0.65 weight ratio of C-4PO-SONa:SMDNS) with 5.3 wt% NaCl was able to form a middle phase microemulsion at a high temperature (40°C),which provided the highest oil removal level with the lowest oil redeposition and the lowest IFT, and was much higher than that with a commercial detergent or de-ionized water. Most of the detached oil, whether in liquid or solid state, was in an unsolubilized form. Hence, the dispersion stability of the detached oil droplets or solidified oil particles that resulted from the surfactant adsorption played an important role in the oil redeposition. For an oily detergency, the lower the system IFT, the higher the oil removal whereas for a waxy (non-particulate) soil detergency, the lower the contact angle, the higher the solidified oil removal. For a liquefied oil, the detergency mechanism was roll up and emulsification with dispersion stability, while that for the waxy soil (solid oil) was the detachment by wettability with dispersion stability.
使用一种基于微乳液的配方研究了聚酯和棉织物上固体非颗粒污垢的洗涤去污力，该配方由一种阴离子型扩展表面活性剂（C-4PO-SONa）和单甲基萘磺酸钠与二甲基萘磺酸钠（SMDNS）作为亲水性连接剂组成，以提供具有超低界面张力（IFT）的Winsor III型微乳液。在这项工作中，熔点约为30°C的棕榈酸甲酯（棕榈酸甲酯）被用作模型固体非颗粒（蜡状）污垢。所选配方（C-4PO-SONa与SMDNS的重量比为4:0.65）的总表面活性剂浓度为0.35 wt%，并添加5.3 wt%的NaCl，能够在高温（40°C）下形成中间相微乳液，该微乳液具有最高的除油水平、最低的油污再沉积和最低的界面张力，且远高于市售洗涤剂或去离子水的相应水平。大部分分离出的油，无论处于液态还是固态，均呈未溶解状态。因此，由表面活性剂吸附导致的分离出油滴或固化油颗粒的分散稳定性在油污再沉积中起着重要作用。对于油性去污，体系的界面张力越低，除油率越高；而对于蜡状（非颗粒）污垢去污，接触角越低，固化油的去除率越高。对于液化油，去污机理是通过分散稳定性进行卷吸和乳化，而对于蜡状污垢（固体油），去污机理是通过具有分散稳定性的润湿性进行分离。
