Process variables that control natural fiber welding: time, temperature, and amount of ionic liquid

Abstract

A systematic study of variables that affect the fiber welding process is presented. Cotton cloth samples are treated with controlled amounts of 1-ethyl-3-methylimidazolium acetate for a series of times and temperatures. Diluting the ionic liquid with a volatile molecular co-solvent allows temporal and spatial control of the welding process not possible with neat ionic liquids. Materials are characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, and mechanical (tensile) testing. Results suggest careful management of process variables permits controlled, reproducible manipulation of chemical and physical properties.

Engineering Lignocellulose Fibers with Higher Thermal Stability through Natural Fiber Welding

“…Upon IL removal, neighboring fibers re‐establish their hydrogen bond networks, delivering a fortified biocomposite which retains much of the polymer's native structure. Previous work in our lab demonstrated how careful control of NFW process variables (i.e., time, temperature, solvent) can significantly improve the tensile strength (in‐line and 45°) of nonwoven cotton cloth . We have also shown how NFW can improve the bulk mechanical strength of biopolymer yarns (i.e., cotton, linen, and bamboo) by more than 30% while incorporating activated carbons to fabricate high performance supercapacitor yarns for knittable textiles, or while integrating Pd‐based nanoparticle catalysts for wastewater treatment .…”

“…The SEM images in Figure show how NFW can change the morphology of yarn. Our early NFW studies focused on how these physical changes impacted material bulk mechanical properties (i.e., modulus, energy to break, etc.) after adjacent fibers mobilized and reformed during welding.…”

Gelation of cellulose-NaOH solutions in the presence of cellulose fibers

“…As all-cellulose composites based on nanocellulose are out of the scope of this thesis, they are not discussed here. Pathway 1 has gained more attention so far; it is based on partially dissolving the surfaces of either aligned cellulose fibers or fabrics, which leads to fibers being "glued" together during coagulation, as illustrated in Figure 3.5 (Soykeabkaew et al 2008;Gindl-Altmutter et al 2012;Haverhals et al 2012;Huber et al 2013;Dormanns et al 2016). Additionally, this approach can be utilised for short fiber "networks" such as isotropic pulp sheets (Gindl et al 2006;Piltonen et al 2016;Hildebrandt et al 2017;Sirviö et al 2017), filterpapers (Nishino & Arimoto 2007; a b…”

Ionic liquids assisted processing of renewable resources for the fabrication of biodegradable composite materials

“…Afterwards, a systematic study of variables that affect the fiber welding process (IL quantity, temperature, time) was presented by Haverhals and co-workers. 182 It was shown that the quantity of IL introduced was the most influential parameter to control the amount and location of biopolymer modification. In addition to material reorganization, natural fiber welding opens biopolymers to possible chemical functionalization at…”