Assembly And Property Of Durable Nanohybrid Superhydrophobic Fabric Coating

In recent years,bionic superhydrophobic fabrics due to its excellent waterproof,anti-fouling and self-cleaning properties,which were widely used in civilian,military,medical and industrial fields.Therefore,it has a wide application value and development prospects on studying superhydrophobic fabrics with environment-friendly and durability.Organic-inorganic hybrid materials have a unique structure and can endow novel properties to the material,and widely used in the biomimetic superhydrophobic fields.Polysilsesquioxane(PSQ)nanohybrid material is a kind of organic-inorganic hybrid material with excellent property.Among them,the inorganic skeleton structure composed of Si-O bonds can endow the material excellent nanosize effect,thermal stability,physiological inertness,and mechanical strength;at the same time,its surface or interior is easily chemically modified and functionalized,which provides convenience for fabrication of high-performance superhydrophobic fabric surface.Therefore,on basis of the "Lotus effect" principle,this paper designed and synthesized two functional PSQ nanohybrids under aqueous system firstly,and then the reacted silanes,the functional PSQ nanohybrids and cross-linked aminosilicone(JASO)were sequentially assembled on the surface of the cotton fabric through layer-by-layer self-assembly(LBL)technology,thereby superhydrophobic fabric with the properties of softness,breathability and durability was constructed.The main research contents of this paper are listed as followings:(1)Assembly and property of polycarboxymethyl/methylsilsesquioxane(PCMSQ)nanohybrid superhydrophobic fabric coatingFirstly,at room temperature,the monodispersed polycarboxyl/methylsilsesquioxane(PCMSQ)nanohybrid materials were prepared via hydrolytic condensation method of sodium hydroxyl as the catalyst,methyltriethoxysilane(MTES)and carboxylated triethoxysilane(CTES)as silicon source,and primary alcobol ethoxylate(AE03/AE09)as mixed emulsifiers in water system.Secondly,the superhydrophobic fabric with the properties of softness,breathability and durability was constructed via LBL technology of y-glycidoxypropyltrimethoxysilane(KH560)monomer silane,functional PCMSQ nanohybrid material,and cross-linked aminosilicone(JASO)emulsion as three building blocks,cotton fiber as a matrix.Finally,the preparation and application process were optimized by single factor experiment.The chemical structure,crystal form,average particle size,micromorphology,and thermal stability of PCMSQ were confirmed by FT-IR,XPS,XRD,DLS,FESEM,AFM,and TGA;the chemical composition and microscopic morphology of superhydrophobicity coating on cotton fabric surface was analyzed by XPS and FESEM;the hydrophobicity,washing durability,softness,air permeability and whiteness of the assembled cotton fabric were measured by OCA,computerized measurement and control softness meter,digital fabric breathability meter,and colorimeter whiteness meter,respectively.Studies have shown that PCMSQ had an expected chemical structure,amorphous form,and good thermal stability;when the mass fraction of AE03/AE09 was 0.36%?0.54%,the concentration of NaOH was 25?50 mmol.L-1 and the ratio of oil to water at 1/12?1/10,a series of PCMSQ NPs with average particle sizes ranged from 100 to 200 nm,uniform size,good sphericity,and smooth surface can be prepared.When the mass fraction of KH560 ethanol hydrolyzate was 0.7%,the solid content of PCMSQ NPs was 1%,and the solid content of JASO emulsion was 1%,the fabric sample is soaked for 1 min,dried at 100 ? for 10 min,and finally set at 160 ? for 1 min.the obtained cotton fabric had superhydrophobic property,and WCA of its surface were up to 156.5°,and the coating had little effect on the air permeability of the cotton fabric,and had good softness and whiteness.In addition,the superhydrophobic fabric had a good washing durability,which WCA still reached 141.2° after 25 cycles of soaping.It should be that the chemical bonding of C-OH in the KH560 hydrolyzate and C-OH on the fabric fiber,Si-OH in the KH560 hydrolyzate and Si-OH in the PCMSQ molecule,and Si-OH and-COOH on the PCMSQ surface and-NH-in the JASO had improved its durability.What's more,the FESEM observation of the superhydrophobic coating on the cotton fabric surface revealed that the PCMSQ nanopatch was absorbed on the cotton fabric fiber surface as monolayers,it formed a micro/nano coarse structure with a micron-sized weaving structure of the cotton fabric fiber itself,and then construction of superhydrophobic fabric was realized.(2)Assembly and property of polydodecyl/methylsilsesquioxane(PDMSQ)nanohybrid superhydrophobic fabric coatingFirstly,an aqueous polydodecyl/methylsilsesquioxane(PDMSQ)nanohybrids were prepared via hydrolytic condensation reaction of sodium hydroxyl as the catalyst,MTES and DTMS as raw materials,sodium dodecyl sulfate(SDS)and polyoxyethylene sorbitan monooleate(T80)as compound emulsifiers at room temperature.Secondly,multi-functional superhydrophobic fabric was obtained via the same method.Finally,the preparation and application processes were optimized by single factor experiment.Analysis by FTIR and XPS showed that PDMSQ had the expected chemical structure.XRD analysis showed that the PDMSQ NPs were of an amorphous structure,and TGA indicated that PDMSQ had good thermal stability.DLS,FESEM and AFM measurements demonstrated that the PDMSQ NPs with uniform size,regularly spherical shape,smooth surface,average particle size of less than 80 nm and narrow particle size distribution were prepared,when w(SDS/T80)was 0.71%,NaOH concentration was 50?100 mmol·L-1,and oil/water ratio was 1:4?6.The optimization of the finishing process conditions revealed that when the mass fraction of KH560 ethanol hydrolyzate was 1%,the solid content of PDMSQ emulsion was 2%,and the solid content of JASO latex was 1%,the fabric after assembly was obtained that had best comprehensive properties.WCA were up to 160.8°,which it had superhydrophobic properties;and WCA could still retain 144.6°after 25 cycles of soaping,which it also had good washing durability.Compared with the above system,the presence of long-chain alkyl groups in PDMSQ was more conducive to reducing the surface energy of the fabric,so it was more hydrophobic.In addition,the superhydrophobic coating had little effect on the breathability of the fabric,and the air permeability was only reduced 0.85 L/m2 ·s.FESEM showed that there was a layer of dense JASO film on the surface of the cotton fabric after assembly,and the PDMSQ NPs were evenly dispersed on the surface of fabric fibers and monolayer-adsorbed.This unique micro-morphology was the key to build a superhydrophobic fabric coating.