ABSTRACT
In this report, a unique methodology/process steps were followed using Sol-gel-based concept to deposit thin flame-retardant coatings on cotton fabric. Surface microstructure and compositional analysis of the coated cotton were carried out using scanning electronic microscope (SEM), which explored significant coverage of the fabric. The obtained samples were further analyzed through rupturing mechanism test and color check. Compositional investigation of the coated samples was carried through Attenuated total reflection Fourier transform infrared (ATR-FTIR) and energy-dispersive X-rays spectroscopy (EDS) analysis. Thermal analyses were carried out through Thermogravimetric analysis (TGA) and Vertical flame tests (VFT), which suggested higher resistance of the coatings obtained for 5 h and zero heat-treatment time on the cotton fabric. A 28.86% char residue was obtained for the same sample (ET-5h-RT) coupled with higher degradation temperature and excellent combustion properties.
ABSTRACT
In this work, starch-clay-TiO2-based nanocomposites were deposited on cotton fabric through layer-by-layer (LBL) process and their effect on the flame retardancy, inhibition of pyrolysis and combustion processes were discussed in details. Polyelectrolyte solutions/suspensions of cationized starch and VMT (vermiculite)/TiO2 nanoparticles were used to deposit these nanocomposites in the form of multi-layered coatings (5, 7, 10 and 15 bilayers). Uniform fabric coverage and presence of electrolytes was imaged by scanning electron microcopy (LV-SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and EDX characterizations. The greatest pyrolysis reduction was found for the StVT-7 sample (7 bilayers); ~30% and 21%, based on microscale combustion calorimetry (MCC) and thermogravimetric analysis (TGA). When using MCC, the improved values of the PHRR ~ 193 W/g, THR ~ 10.7 kJ/g), HRC ~ 390 J/gâK and LOI ~ 22.2% were found for the StVT-7 sample which was strongly supported by the UL-94 test.
ABSTRACT
In the present work flower-like, α-Fe2O3 were synthesized by ethylene-glycol mediated polyol method. The synthesized flower-like, α-Fe2O3 were separated cadmium (Cd2+) chromium (Cr6+) and lead ions (Pb2+) from wastewater. XRD pattern and FESEM images show the obtained sample is pure hematite and flower-like nanostructures average particle sizes 4.0 µm. The BET specific surface area was 47.55 m²g-1. Adsorption experiments were investigated the adsorbent dose, influence pH of the metal ions, sorption times and initial concentrations of heavy metal ions. High efficiency of Cd2+, Cr6+ and Pb2+ removal occurred at pH 7.0, 3.0 and 5.5, respectively. The adsorption equilibrium study showed that the heavy metal ions adsorption of flowers like α-Fe2O3 followed a Langmuir and Freundlich isotherm model. The heavy metal ions adsorption equilibrium data were followed to the Langmuir model. The maximum adsorption capacities were 16.95, 22.22 and 25.64 mg g-1 for Cd2+, Cr6+ and Pb2+ ions respectively. This work determines that the synthesized flower-like α-Fe2O3 is proposed as an efficient nano-adsorbent for wastewater treatment.
