A Facile Approach for the Fabrication of Highly Stable Superhydrophobic Cotton Fabric with Multi-Walled Carbon Nanotubes−Azide Polymer Composites

Abstract

Homogeneous dispersion and functionalization of pristine multiwalled carbon nanotubes (MWNTs) in various organic solvents was achieved by a simple ultrasonic process in the presence of an azide copolymer, poly(4-azidophenyl methacrylate-co-methyl acrylate)(P(APM-co-MA)). The copolymes were noncovalently attached to the surface of the MWNTs via pi-pi interactions to form MWNT-P(APM-co-MA) composites. The composites were characterized by transmission electron microscopy, thermogravimetric analysis, Raman spectra and UV-vis spectra. The solution dispersion of the MWNT-P(APM-co-MA) composites were used to prepare superhydrophobic cotton fabric by a facile dip-coating approach. MWNTs were covalently attached to the surface of the cotton fabric through the chemical reactions between the azide groups of P(APM-co-MA) with both MWNTs and cotton fibers. The reactions are based on UV-activated nitrene chemistry. Owing to the nanoscale roughness introduced by the attachment of MWNTs, the cotton fabric surface was transformed from hydrophilic to superhydrophobic with an apparent water contact angle of 154 degrees . Since MWNTs were covalently attached on the surface of the cotton fabric, the superhydrophobicity possesses high stability and chemical durability.

The superhydrophobicity of polymer surfaces: Recent developments

“…49 An interesting variation on this has been to coat cotton fibers with carbon nanofibers with a polymer linkage. 50 This has shown good properties against washing and similar surfaces have resisted hot water, 51 factors often causing problems for superhydrophobic textiles. This extreme resistance is probably due to the multiple length scale overhanging fiber structure for reasons described later.…”

Functionalization of textiles with multi-walled carbon nanotubes by a novel dyeing-like process

“…The same authors also deposited unmodified MWCNTs onto cotton by ultrasonic irradiation followed by the dipping method; however, in this case, although the CNTs imparted some hydrophobicity to the fabric, this property was not durable [21]. In a distinct approach, MWCNTs previously oxidized and sequentially functionalized with pending dihydroxyphenyl groups and a perfluoroalkoxysilane were impregnated in cotton, endowing superhydrophobicity to the fabric [25]. Very recently, a superhydrophobic cotton was fabricated by dip coating with a MWCNT-poly(4-azidophenyl methacrylate-co-methyl acrylate) composite followed by UV irradiation [25].…”

“…In a distinct approach, MWCNTs previously oxidized and sequentially functionalized with pending dihydroxyphenyl groups and a perfluoroalkoxysilane were impregnated in cotton, endowing superhydrophobicity to the fabric [25]. Very recently, a superhydrophobic cotton was fabricated by dip coating with a MWCNT-poly(4-azidophenyl methacrylate-co-methyl acrylate) composite followed by UV irradiation [25]. In another study, MWCNTs were noncovalently functionalized with an organic-inorganic hybrid composed of silica and an amphiphilic copolymer of styrene and maleic anhydride and then coated with tetraethylorthosilicate and a fluoroalkoxysilane [23]; cotton cloths were coated with this composite, presenting superhydrophobicity and improved conductivity.…”

Turning polysaccharides into hydrophobic materials: a critical review. Part 1. Cellulose

“…Consequently, the original hydrophilic character of all these surfaces disappeared after the treatment and, in the case of the cellulose substrate, the water contact angle increased from 30°to more than 120°, for the most fluorinated surfaces. The non-covalent attachment of different polymers onto the surface of cellulose fibers can be carried out using several techniques, such as by pickering emulsions (Bayer et al 2009), layer-by-layer or multi-layer deposition (LbL) (Gonçalves et al 2008(Gonçalves et al , 2009Ogawa et al 2007;Yang and Deng 2008), dipcoating or immersion in the polymer solution (Daoud et al 2004;Li et al 2008Li et al , 2010bTang et al 2010;Vilčnik et al 2009;Xu et al 2010;Xue et al 2008), impregnation (Vince et al 2006), physical deposition (Li et al 2010a;Zhang et al 2003), electro-spraying (Sarkar et al 2010) or simply heating (Vilčnik et al 2009). …”