Process Variables that Control Natural Fiber Welding

Abstract

Preliminary data are shown for a systematic study of the variables that control the fiber welding process. Cotton cloth samples are treated with various amounts of 1-ethyl-3-methylimidazolium acetate for a series of times and temperatures. Processed materials are characterized by scanning electron microscopy, infrared spectroscopy, x-ray diffraction, and mechanical (tensile) testing. Chemical and physical properties are shown to be controllably modified with careful management of process variables.

Lignocellulose Fiber- and Welded Fiber- Supports for Palladium-Based Catalytic Hydrogenation: A Natural Fiber Welding Application for Water Treatment

“…NFW is quite versatile, as any number of ILs can be applied to natural fiber materials including lignocellulose (e.g., cotton, linen, hemp, bamboo) and other biopolymers (e.g., silk, chitin). Additionally, studies have shown that NFW can maintain or improve the mechanical properties of the underlying natural fiber supports, ,− extending their use to more advanced engineering applications. In previous work, researchers at the U.S.…”

“…24 Padalkar et al developed nanofabrication techniques to control and optimize monometallic nanoparticle deposition onto cellulose nanocrystals. 25 A distinct advantage of lignocellulose over conventional catalyst supports is that it can be postprocessed through natural fiber welding (NFW) 26 into free-standing structures. In NFW, lignocellulose fibers are partially dissolved and mobilized upon exposure to controlled amounts of ionic liquid (IL), then reorganized upon IL removal.…”

“…For the NFW process, a tubular linen support was first prepared from partial dissolution and reconstitution of linen yarn in an IL, 1ethyl-3-methyl imidazolium acetate (EMI-Ac), based on previously reported methods. 26 Next, a certain amount of linen-supported Pd− Cu catalyst was dissolved with EMI-Ac and acetonitrile, and the resulting "catalytic ink" was fiber-welded onto the tubular linen support under vacuum at 60 °C.…”

Deconstruction and Reassembly of Renewable Polymers and Biocolloids into Next Generation Structured Materials

“…mobility to interact more intimately with adjacent fibers. 748 As far as cellulose fibers, while one may expect individual fibers to be weakened due to the conversion of highly crystalline cellulose I into less ordered cellulose II, the structural integrity of the fibrous network is likely to be improved through more extensive interactions, leading to reinforced materials. Indeed, ionic liquid-welded, hot-pressed CNF films were found to be surface patterned, more transparent, stiffer and tougher than the untreated film.…”

“…738 The welding extent is controlled primarily by the temperature (controls mostly swelling and dissolution rates), time (controls mainly penetration depth and net dissolution extent) and pressure plus the characteristics of the solvent itself, such as chemical nature and concentration. 748,750 Besides spinning or extruding biopolymeric dopes and inducing alignment, for example, into yarns, anisotropy is achievable by restricting the macromolecular rearrangement when drying stresses are developed upon solvent removal. This is the case of cellulose or alginate physical gels that are air-dried under confinement in the axial direction.…”