Research Of Functional Cotton Fabric Surface Fabircated Via Mist Polymerization

Recently, superhydrophobic surfaces have received widespread attention due toits self-cleaning performances. Cotton fabrics are widely applied in various industrialand daily-life fields, which makes the hydrophobic modification of cotton fabricpractically important. Main methods for fabrication super-hydrophobic cotton fabricsare sol-gel, solution-immersion, dip-coating, one-pot and many others. They have acommon in the dip-dry-cure finishing process. Nevertheless, the impregnation inchemical reagents will affect the good cotton properties such as the softness,absorbent, breathable and non-irritating properties. Therefore, the improved wettingproperty of cotton surface hardly use to practical applications.To solve above problems, we proposed a mist polymerization method for surfacemodification. A monomer solution was atomized into fine droplets first, delivered toan activated cotton surface, and grafted on surface by the free radical polymerization.The activated cotton surface was obtained by atomizing the aqueous solution ofammonium ceric nitrate on the cotton fabrics. The trifluoroethyl methacrylate(TFEMA) and lauryl methacrylate (LMA), divinylbenzene (DVB) and ethylene glycoldimethacrylate (EGD) were used as monomer and cross-linking agent, respectively.Surface morphology, wetting property, stability of hydrophobicity, water absorptionand permeability of cotton fabrics were characterized. The effect of monomerconcentration, treatment time, cross-linking agent concentration and solvent type wereinvestigated.When2.12mol/L TFEMA-DVB solution was used, XPS spectrum of themodified cotton surface exhibited two new distinctive signals attribute to Ce3d andF1s peaks. In FTIR-ATR spectra, peaks at1716cm-1and in1500-1600cm-1appeared,they are correspond to the C=O and benzene ring, respectively. These data suggestthat TFEMA has been grafted to cotton fiber surfaces. After this finishing process, thesurface contact angle exceed to151°and a good hydrophobic stability was observed. The modified cotton fabrics still have excellent water absorbability and airpermeability, about90%and96%of the original cotton fabrics, respectively.When0.17mol/L LMA-EGD solution was used, the XPS spectra indicated thatcarbon content increased from59.3%to74.3%, while O/C ratio decreased from0.686to0.297by the modification. Peaks at2850cm-1and1720cm-1in FTIR-ATRspectra are attributed to–CH2and C=O structure, respectively. Besides, SEM imagesshowed that cotton fiber surfaces after finishing by monomer solution and by puresolvent are quite different, indicating that surface roughness increased due to theLMA mist polymerization. By changing the cross-linker concentration or solvent,nano-structured particles appeared. When the monomer/cross-linker=10:1in molarratio, and n-octanol solvent, the surface contact angle came up to160°. While78%and95%of water absorbability and air permeability of the original cotton fabricswere remained, respectively.Mist polymerization applied to cotton fabric surfaces modification revealed itsvarious advantages including less monomer dosage, simple operation, controllablereaction, maintain the original properties of materials and so on. It shows greatpotential application in surface modification of other textile materials.