Polydopamine‐Graphene Oxide Flame Retardant Nanocoatings Applied via an Aqueous Liquid Crystalline Scaffold

Abstract

A highly effective flame retardant (FR) nanocoating was developed by conducting oxidative polymerization of dopamine monomer within an aqueous liquid crystalline (LC) graphene oxide (GO) scaffold coating. Due to its high water content, the LC scaffold coating approach facilitated fast transport and polymerization of dopamine precursors into polydopamine (PDA) within the water swollen interlayer galleries. Uniform and periodically stacked (14.5 Å d-spacing) PDA/GO nanocoatings could be universally applied on different surfaces, including macroporous flexible polyurethane (PU) foam and flat substrates such as silicon wafers. Remarkably, PDA/GO coated PU foam exhibited highly efficient flame retardant performance reflected by a 65% reduction in peak heat release rate at 5 wt% PDA/GO loading in an 80 nm thick coating. While many physically mixed flame retardants are usually detrimental to the mechanical properties of the foam, the PDA/GO coating did not affect mechanical properties substantially. In addition, the PDA/GO coatings were stable in water due to the intrinsic adhesion capability of PDA and the transformation of GO to the more hydrophobic reduced GO form. Given that PDA is produced from dopamine, a molecule prevalent in nature, these findings suggest that significant opportunities exist for new polymeric FRs derived from other natural catechols.

Perspectives in Liquid-Crystal-Aided Nanotechnology and Nanoscience

“…Very recently, a systematic analysis of the electro-optical response of GO LCs under alternating fields was presented by Guerrero et al [378] and a shear-induced stripe assembly was reported by Hong et al [379]. Due to these intriguing physical properties, various potential applications based on GO LCs (Figure 15c-e), such as GO LC gels with "shape memory" effect [380], photoluminescence imaging [381], nanocomposites [382][383][384], sensitive strain sensors [385], transparent electrodes [386], conductive fibres [387][388][389][390], multifunctional yarns [391] and membranes [392], flame-retardant nanocoatings [393], optical devices [394] and biomedical applications [395], have been anticipated and some of them have been realized. More relevant information can be found in a recent review published by Sasikala et al [396].…”

Montmorillonite-Synergized Water-Based Intumescent Flame Retardant Coating for Plywood

“…The FTIR spectra of materials are presented in Figure 3b and their wavelength ranges including 3380 cm −1 , between 1500 and 1600 cm −1 , between 1000 and 1200 cm −1 , 790 cm −1 and 670 cm −1 . The 3380 cm −1 absorption band is responding to stretching vibration of N-H (νN-H) [27][28][29][30]. The characterized absorption peaks are observed in all samples.…”

Two in One: Modified Polyurethane Foams by Dip‐Coating of Halloysite Nanotubes with Acceptable Flame Retardancy and Absorbency

“…Among them, polyurethane foam (PUF) is the most used PU product, which is widely used in modern home decoration in soft furniture . Generally, PUF has merits including low density, high adsorption, good air permeability, low compression deformation, resistance to organic solvents, ventilation, sound insulation, and heat preservation . The common application of PUF is filling materials in furniture mats, vehicle seat mats, and various soft padded laminate composite .…”

“…[3,4] Generally, PUF has merits including low density, high adsorption, good air permeability, low compression deformation, resistance to organic solvents, ventilation, sound insulation, and heat preservation. [5][6][7] The In recent years, as a natural 1D nanomaterial with abundant resources, halloysite nanotubes (HNTs) have attracted a lot of attention in the application of functional materials. [29] HNTs come from natural silicate clay mineral, which exists mainly in the form of nanotubes.…”