University of Batna 2
Discussion
Started 22 July 2024
What happens to hydrophilicity and water absorption of natural fibers after NaOH treatment ?
As far as my understanding goes, the intention of alkali treatment is to remove non-cellulosic hemicellulose, lignin, wax and other impurities and enhance the surface roughness and crystallinity. The molecular chains of cellulose rearrange themselves into closely packed long chain, thereby increasing the crystallinity. When non-cellulosic components that seal the gap between the microfibrils are removed the surface roughness increase.
However, when non-cellulosic components like hemicellulose and wax are removed, that exposes more hydrophilic cellulose to water. Also, lignin is hydrophobic, when it is removed all we have a hydrophilic cellulose.
All replies (3)
Slope is an important indicator of soil erosion susceptibility, but relying solely on it is insufficient due to various limitations. The effectiveness of slope as an indicator varies by geographical region and soil type, necessitating the inclusion of complementary factors such as soil composition, vegetation cover, and rainfall patterns. Research shows that integrating these variables leads to more accurate erosion predictions. Current erosion models, like RUSLE, enhance predictive power by considering multiple factors alongside slope.
University of Batna 2
NaOH treatment of natural fibers reduces hydrophilicity and water absorption by removing non-cellulosic components like hemicellulose and lignin, which enhance cellulose content. This treatment increases surface roughness and crystallinity, leading to a more closely packed cellulose structure. Although more hydrophilic cellulose is exposed, the overall effect is a decrease in hydrophilicity due to increased crystallinity. Consequently, these changes improve the compatibility and mechanical properties of composite materials made with natural fibers.
South-West State University
You asked the question and answered it yourself. Since the fibers are hydrophilic, they interact better with water, water spreads better along the fibers. They are better wetted by water. They interact better with a hydrophilic matrix. To interact with a hydrophobic matrix, they must be hydrophobized. Copper nanoparticles are well distributed in them.
Biocidal cotton material with copper nanoparticles was prepared by treating cloth surface with copper hydroxide in ammonia solution and by coagulation of surface gel and evening of the fiber surface followed by reduction of copper complexes to the atoms and nanoparticles.
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