Layered double hydroxide interfaced stearic acid – Cellulose fibres: A new class of super-hydrophobic hybrid materials

Technical composite materials derived from renewable sources are always of high importance due to cost-effectiveness and environmental concern. Cellulose, a renewable biopolymer stays constantly at the high realm in terms of valorization for functional materials, chemicals and other raw-materials. Cellulose based moisture-repellent materials have challenged the chemists in recent decade as the inherent hydrophilic nature of cellulose should be overcome by chemical modification or hydrophobic insulation. In the present study, cellulose is hydrophobized by eco-friendly stearic acid (SA) through inorganic linker/interface/sandwich material namely layered double hydroxides (LDH) for the first time as the layers have affinity to both cellulose and stearic acid at molecular level. The novel idea of utilizing the charge centres on LDH has been effectively materialized to make conjugation with hydrophobic SA and hydrophilic cellulose simultaneously. This produces an entirely new kind of hybrid material which offers not only hydrophobicity but super-hydrophobicity to cellulose network. This novel SA-LDH-CEL interfaced composite material surpasses all other materials that have been reported in the literature in terms of its water-repellency which is a mandatory requirement for water-proof packaging, thin films, paper, sorbent and sanitary materials.