The Study Of Surfactants In Increasing Cotton Fabrics Dehydration Efficiency

Improving the efficiency of cotton fabric dehydration can reduce both the energyconsumption of the fabric dehydration process, and the time required to dry the fabric.But the ways to increase dehydration efficiency are overall from the fields which arerestricted to physical, mechanical, thermodynamic (such as the improvement ofdrying machine, development of fiber materials and drying process optimization), buttheir theoretical researches have been studied systematically and the further studyspace will be very limited. In this research, relying on the theory of surface chemistry,the influence of liquid surface tension, fabric in-situ surface energy, or the synergybetween them to the fabric dehydration efficiency were studied. In order to obtainhigher dehydration efficiency, a better surfactant system was received by the way ofsurfactant compound. Finally, a series of quaternary ammonium salt cationic Geminisurfactants with ester spacer were synthesized to provide a direction of synthesizingnovel specialized surfactants for dehydration.The major work can be summarized as follows:(1) A series of fluorosurfactantswith clear structures were selected as additives to investigate the dehydrationefficiency of cotton fabrics. The impact of in-situ fabric surface energy under liquidsolution which is measured by captive octane droplet method on residual moisturecontent (RMC) of fabrics in dehydration processes was investigated. The theoreticalresearch to increase the cotton fabric dehydration efficiency from surface chemistryfield was enriched by the above studies.(2) A cationic surfactant(N,N,N-trimethyl-3-(perfluorooctylsulfonamido)propan-1-aminiumiodide, I) is mixedwith other types of surfactants in order to study the influences of the mixing on liquidsurface tension and cotton fabric surface energy in aqueous solution, and theapplication of surfactant mixture systems in dehydration of cotton fabrics.(3) A seriesof quaternary ammonium Gemini surfactants (differing in their spacer group and hydrophobic chain) with ester-based in the spacer were synthesized. They werestructurally characterized by NMR (1H and19F), ES-MS and elemental analysis. Theequilibrium surface tension properties and Synergistic Properties of FluorocarbonGemini surfactants with SDBS were investigated.The main results are as follows:(1) The liquid surface tension and RMC can beefficiently decreased when fluorocarbon surfactants are used. In addition to the liquidsurface tension, the in-situ surface energy of fabric under water is also an importantfactor in dehydration efficiency. Notably, cationic fluorocarbon surfactant displayssimilar surface tension but distinct dehydration efficiency.(2) By the way of mixingthe surfactants can not only reduce the liquid surface tension, but also can reduce thein-situ surface energy of the cotton fabrics under water. The mixed system is moreeffective than both single surfactant components in reducing the surface energy ofcotton fabrics in aqueous solution due to synergistic effects, and can be used toeffectively improve the dehydration efficiency of cotton fabrics.(3) The synthesizedGemini surfactants exhibited excellent surface activity in the lower CMC andremarkable synergistic property with SDBS. It is possibly since the overlongspacer,this kind of Gemini surfactants synthesized show a bad solubility, and finallylead to a high level surface tension. The synergistic system of fluorocarbon Geminisurfactants (5a or5b) and SDBS can lower the liquid surface tension from30mN/mto17mN/m due to their superior synergistic effect.