Influence of mild alkaline treatment on the cellulosic surfaces active sites

Abstract

Agro-residues fibers are inexpensive environmentally friendly alternatives to synthetic fibers in fiberreinforced polymer composites. The natural fiber properties and bondability with adhesive can be modified by subjecting the fibers to a pre-treatment procedure. The knowledge of the modified fibers surface properties is essential to explain and predict their applications. The present study is focused on the effect of alkaline treatment on the surface characteristics of stalk fibers from rapeseed, tobacco, cotton, lemon balm and kiwi. The chemical composition of fibers and Fourier transform infrared spectroscopy show components extraction and the X-ray diffraction show improvement in the crystallinity index of the treated fibers. But only the IGC analysis allows us to know in detail the alterations on the fiber surface and the effect on the adhesion of the fibers. IGC shows that alkaline treatment produces changes in the nature and number of the active sites, responsible for the physico-chemical activity of the surface of the fibers. The fiber hydrophobicity was improved by the increase of more energetic and active sites in the surface. Also, the creation of new basic active sites and removal of acidic active sites from the fiber surface due to alkaline treatment has been clearly shown.

Effects of hot water pre-extraction on surface properties of bagasse soda pulp

“…As the lignin is less hydrophilic than cellulose and hemicelluloses [13], the decrease (from 46.00 to 43.90 mJ/m 2 ) in the γ S D was observed. In a previous work, a similar decrease was observed when the bagasse fiber was subjected to 1% of NaOH extraction [25]. Also, the same reduction in the γ S D values has been reported after steam explosion of bio-fibers [26], attributed to the protective coating formed by the moieties created by the partial depolymerization of lignin.…”

Towards plant protein refinery: Review on protein extraction using alkali and potential enzymatic assistance

“…Treatment of fibrous material at alkaline pH can also result in the disruption of cell wall surface properties. This involves a reduction in surface tension, partial removal of lignin, and complete removal of acetyl or uranic esters group of hemicellulose [38]. Also crystallinity of cellulose can be reduced following alkaline treatment [39].…”

Multifunctional finishing of cotton fabric based on in situ fabrication of polymer‐hybrid nanoparticles

“…Over the past few decades, modification of natural fibers and functional finishing of textiles have attracted tremendous attention because of increasing awareness of human beings toward environmental protection and healthy, safe, and comfortable life . They can impart desired functional properties to the fibers and textiles for their applications, such as ultraviolet (UV) resistance, antibacterial resistance, flame retardancy, antistatic, conductivity, hydrophobic, and hydrophilic surface .…”