Layer by Layer coatings assembled through dipping, vertical or horizontal spray for cotton flame retardancy

Area of Science:

• Materials Science
• Textile Engineering
• Nanotechnology

Background:

• Cotton fibers possess inherent flammability, limiting their use in applications requiring high safety standards.
• Developing effective flame retardant treatments for natural fibers like cotton is crucial for enhancing material safety and performance.

Purpose of the Study:

• To investigate the efficacy of silica-based assemblies deposited via the Layer-by-Layer technique for enhancing cotton's flame retardant properties.
• To compare the impact of different deposition methods (dipping, vertical spray, horizontal spray) on coating morphology and flame retardancy.

Main Methods:

• Layer-by-Layer (LbL) deposition of silica assemblies onto cotton fibers.
• Morphological characterization using Scanning Electron Microscopy (SEM) and elemental analysis.
• Flammability assessment through standard flammability tests and cone calorimetry.

Main Results:

• Horizontal spray deposition resulted in highly homogeneous silica coatings on cotton fibers, unlike dipping or vertical spray methods.
• Fabrics treated with horizontal spray exhibited significantly increased total burning time and final residue.
• Cone calorimetry revealed a notable increase in time to ignition and a substantial reduction in heat release rate and total heat release.

Conclusions:

• The horizontal spray method is optimal for achieving uniform silica coatings on cotton fibers using the LbL technique.
• Silica-based assemblies deposited via horizontal spray significantly enhance the flame retardant performance of cotton textiles.
• This approach offers a promising strategy for developing safer, flame-retardant cellulosic materials.