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.

Highly Anisotropic Corncob as an Efficient Solar Steam-Generation Device with Heat Localization and Rapid Water Transportation

“…The chemical compositions of the corncob and C-corncob were identified by FTIR and XPS analyses. In the FTIR spectra, the peaks around 1592 and 1069 cm –1 are the characteristic peaks of N–H and C–N, respectively (Figure c). ,,, As shown in Figure d, the corncob and C-corncob show the same peaks around 284.6, 532.7, and 399.9 eV, which are ascribed to the C 1s, O 1s, and N 1s signal, respectively. In the N 1s spectra, the strong peak of C–N/N–H around 399.9 eV is clearly presented, confirming the existence of nitrogen functional groups in the C-corncob (Figure e).…”

Assembly of Graphene Oxide Nanosheets on Diamine-Treated PVDF Hollow Fiber as Nanofiltration Membranes

“…However, considering the high reactivity between amine and oxygen groups (such as the nucleophilic attack of nitrogen to carbonyl group), there could be amide bond formation of GO-COOH groups or ring-opening reaction of the GO-epoxide group . Besides, because alkaline amines can reduce GO at elevated temperatures (70 °C in our case), enhanced π–π interaction between graphene sheets could contribute to the high film stability …”

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.…”