Construction of hierarchical layered double hydroxide/poly(dimethylsiloxane) composite coatings on ramie fabric surfaces for oil/water separation and flame retardancy

摘要

Nano/micro composite coating is an important method to fabricate the multifunctional ramie fabrics. Here, layered double hydroxides with different morphologies and poly(dimethylsiloxane) (PDMS) are grown on ramie fabric surfaces to endow ramie fabrics with superhydrophobic and flame retardant abilities. The superhydrophobic and superoleophilic ramie fabric is a very promising material for oil spill cleanup in an environmentally friendly way. The experiment shows that the as-fabricated ramie fabrics with superhydrophobic surface can not only exhibit high separation efficiency in oil/water separation tests, but also present good heat-resistance, mechanical and chemical stabilities in extreme environments. Moreover, to evaluate the environmental adaptability of superhydrophobic and superoleophilic ramie fabrics in a combustion environment, the thermal stability and flame retardant performance were investigated through thermosgravimetric analysis, and vertical burning test (UL-94). Also, the flame retardant mechanism was further studied by char residue analysis with scanning electron microscope and X-ray diffraction. Thus, this work offers a feasible way to design and prepare nano/micro composites coated renewable cellulosic fabric for wearable devices, oily wastewater treatment and flame retardancy.