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Surface Treatments Of Natural Fibres In Fibre Reinforced Composites: A Review

Seisa Keolebogile, Chinnasamy Vivekanandhan, Ude Albert U.

Fibres & Textiles in Eastern Europe

2022

Vol. 30, no. 2

82--89

The use of natural fibres in fibre-reinforced composites comes with drawbacks. They are highly hydrophilic, leading to high moisture absorption and poor interfacial adhesion in matrix-reinforcement bonds. This affects the fibres’ thermal stability as well as mechanical properties, hence limiting their wider application. This paper reviewed different ways in which natural fibres have been treated to improve hydrophobicity, reinforcement-matrix interfacial adhesion and thermal stability. It will investigate. among others, treatments like alkali, acetylation, bleaching, silane, benzoylation and plasma, which have been found to improve fibre hydrophobicity. The literature reviewed showed that these methods work to improve mechanical, chemical, and morphological properties of natural fibres by removing the amorphous surface, thus allowing for more efficient load transfer on the fibre-matrix surface. Studies in the literature found alkali treatment to be the most common surface modification treatment due to its simplicity and effectiveness. However, plasma treatment has emerged due to its lower processing time and chemical consumption. A comparative analysis of other improved properties was also investigated.

Physical and chemical mechanisms of hydrophobicity of nanoparticle membranes (Mg+Al2O3)

Wahyudi Wahyudi, Subagyo R., Gapsari F.

Journal of Achievements in Materials and Manufacturing Engineering

2019

Vol. 96, nr 2

57--68

Purpose: Investigate the hydrophobic, superhydrophobic and hydrophilic properties of Alumina (Al2O3) and Magnesium (Mg) nanoparticles. Design/methodology/approach: This research was conducted by SEM-EDX analysis of Magnesium and Alumina nanoparticles, observation of gas bubbles when droplets of water contact with membrane surfaces, measurement of surface roughness and detection of Hydrogen gas production using Gas Chromatography. There are eleven compositions (Al2O3:Mg) membranes used in this study, namely: (0:100; 10:90; 20:80; 30:70; 40:60; 50:50; 60:40; 70:30; 80:20; 90:10; and 100:0). Findings: Successfully found an alloy membrane between Alumina (Al2O3) and Magnesium (Mg) nanoparticles in the composition of Mg:Al2O3 (0:100%) having Hydrophobic properties; Mg:Al2O3 (50:50%) has Superhydrophobic properties and Mg:Al2O3 (100:0%) has hydrophilic properties. Three conditions occur when H2O droplets come in contact with the membrane layer, namely: hydrophobic conditions when the trapped gas pressure is smaller than the droplet pressure. Superhydrophobic conditions when the trapped gas pressure is equal to the droplet pressure. Hydrophilic conditions occur when the trapped gas pressure is greater than the droplet pressure. Research limitations/implications: This research is limited to the hydrophobic nature of Nano Alumina (Al2O3) and Magnesium (Mg) membrane particles. Practical implications: Superhydrophobic properties are very suitable to be applied to membranes that are useful for destiny. Originality/value: The novelty of this study is to find the right mixture of nanoparticles of Alumina and Magnesium in a composition that is capable of creating hydrophobic, superhydrophobic and hydrophilic properties.

The Mechanism of Formation of Finely Dispersed Minerals on the Surface of Diamonds and the Application of Electrolysis Products of Water Systems for their Destruction

Chanturiya Valentin, Dvoichenkova Galina, Morozov Valery, Podkamenny Yury, Kovalchuk Oleg

Inżynieria Mineralna

2019

R. 21, nr 1

53--57

The composition of the surface of natural diamonds in interaction with kimberlite minerals and the aqueous phase in the deposit and enriched ore is studied. The sequence and conditions for the formation of minerals on the surface of crystals under conditions of processing of kimberlites have been determined. Confirmed the mechanism of hydrophilization of diamonds comprising crystallization of hydroxides and oxides of iron as a mandatory initial stage. A method of destruction or subsequent dissolution of minerals aggregates by the impact of electrolysis products of aqueous systems has been proposed, which allows to restore the hydrophobicity of diamonds. The use of electrochemically treated water in the froth separation cycle with high diamond recovery made it possible to increase their recovery in the factory’s concentrate by 8.8%.

Zbadano skład powierzchni naturalnych diamentów w interakcji z minerałami kimberlitowymi i fazą wodną w złożu i wzbogaconej rudzie. Określono kolejność i warunki tworzenia minerałów na powierzchni kryształów w warunkach przetwarzania kimberlitów. Potwierdzono mechanizm hydrofilizacji diamentów obejmujący krystalizację wodorotlenków i tlenków żelaza jako stały etap początkowy. Zaproponowano sposób niszczenia lub późniejszego rozpuszczania agregatów minerałów przez wpływ produktów elektrolizy układów wodnych, co pozwala przywrócić hydrofobowość diamentów. Zastosowanie elektrochemicznie uzdatnionej wody w procesie separacji piany z wysokim odzyskiem diamentu umożliwiło zwiększenie odzysku w koncentracie o 8,8%.