Water Absorption Of Fibers Research Articles

Preparation and properties of pretreated jute fiber cement-based composites

In order to resolve the contradiction of poor compatibility between plant fiber and cement-based materials and improve the toughness and durability of cement-based composites, this paper takes jute fiber cement-based composites as the research object, and proposes the pretreatment method of jute fiber through mass loss rate and water absorption test. The influence of pretreated jute fiber on the properties of cement-based composites was investigated by means of mechanical properties and frost resistance tests. The strengthening mechanism of jute fiber in the pre-treatment of cement-based composite materials was revealed from a microscopic perspective using scanning electron microscopy and mercury porosimetry. The results indicate that the quality loss rate of jute fiber soaked in hot alkali solution ( 60 ℃, 4% NaOH solution) was the largest, which was 37.94%. After dipping in 10% chloroprene latex, the fiber water absorption was the smallest, which was 0.93%. Therefore, the jute fiber was pretreated by the combination of hot alkali solution soaking and chloroprene latex impregnation. The pretreatment of fibers will reduce the fluidity of the composites, but has little influence on the setting time of the composites. The flexural strength, splitting tensile strength, dry shrinkage and frost resistance of the composites are significantly improved by the pretreatment fiber, but the compressive strength is slightly insufficient. The jute fiber after pretreatment can achieve reinforcement, crack resistance and toughening, reduce the porosity of cement-based composites, and optimize the pore structure inside the cement-based composites.

Agarose fibers with glycerol and graphene oxide and functional properties for potential application in biomaterials

Agarose has numerous applications in biochemistry and medical textiles. This study aimed to produce agarose-graphene oxide-glycerol fibers and analyze their properties. The agarose gel was prepared by dissolving the polymer in 9:1 (v/v) dimethyl sulfoxide (DMSO): H2O, followed by spinning in an ethanol bath (1:1 (v/v) ethanol: H2O) at 20 °C. Fibers were obtained using 8 % (m/v) agarose, 2 % (m/v) glycerol, and 0.5 % and 1 % (m/v) graphene oxide (GO). The fibers had a titer of 18.32–32.49 tex and, a tenacity of 1.40–3.35 cN/tex. GO increased the thermal resistance by 79 %. The presence of glycerol and GO was confirmed and analyzed by FTIR and XPS. Fiber water absorption was decreased by 30 % with the GO addition. The weight loss increased by 55 % after glycerol addition, 51 % with GO addition, and 36 % with glycerol and GO simultaneous addition. Furthermore, GO exhibited 100 % inhibition for both S. aureus (gram-positive) and E. coli bacteria (gram-negative). Fiber F1, with only agarose, inhibited S. aureus by 34.93 %, F2 with 2 % glycerol by 48.72 %, F3 with 0.5 % GO by 63.42 %, and F4 with 2 % glycerol and 0.5 % GO by 30.65 %. However, the inhibition increased to 49.43 % with 1 % GO. The agarose fibers showed low inhibition for E. coli, ranging from 3.35 to 12.12 %.

Study on water absorption of hydrophobically modified ramie fiber and the reinforced polypropylene composites

AbstractTo study the effects of fiber surface hydrophobicity on water absorption of composites, ramie fiber was hydrophobically modified with polydopamine/octadecylamine and then used to reinforce polypropylene. The fiber modification was characterized by infrared spectroscopy, scanning electron microscopy, energy spectrometry, contact angle, and water absorption. The mechanical properties and water absorption of the composites were also characterized. The results indicated that polydopamine/octadecylamine was successfully grafted onto the fiber surface. With the increase of octadecylamine concentration, the fiber surface became more and more hydrophobic, and its contact angle achieved a maximum of 118 ± 2.97° when octadecylamine concentration was 8 g/L. However, the modified fiber remained a high level of saturated water absorption of 6.53% ± 0.09%. For composites, when the octadecylamine concentration was 0.5 g/L, its water absorption showed the lowest value of 1.81% ± 0.09%. With more octadecylamine was grafted onto the fiber, the water absorption did not decrease continuously but showed a small growth peak. It is concluded that water absorption of composites is greatly affected by water absorption of fiber. The surface hydrophobic modification on fiber is beneficial to improve its surface hydrophobicity and inhibit the interfacial water absorption between fiber and matrix. However, it fails to the improve internal hydrophobicity of the fiber, nor does it inhibit the fiber in composites from absorbing water.

Characterization and resistance against the combined effect of chloride erosion and freeze–thaw cycling of sticky rice lime paste enhanced by cellulose fiber and fly ash

The primary objective of this paper is to research the characterization and durability enhancement of traditional sticky rice air lime paste mixed with cellulose fiber and fly ash. The changes in the physical and mechanical properties, pore structure and microstructure and the deterioration mechanism of the durability under the combined action of chloride erosion and freeze–thaw cycling of modified sticky rice air lime paste are studied by means of macro test, NMR, XRD, FTIR and SEM. The results show that cellulose fibers can effectively reduce the drying shrinkage, improve the compressive and flexural strength, and resist the expansion of cracks caused by freeze–thaw cycles. However, when the fiber is added alone, the water absorption of the fiber will delay the carbonization rate and adversely affect the frost resistance of the paste. The mixture of fly ash and fiber can be used to fill the pores, solidify chloride ions, reduce the adverse effects on frost resistance caused by the fiber's water absorption, and enhance the strength and durability of the paste. The modified paste mixed with 1% fiber and 25% fly ash has favorable strength and resistance to the combined effect of chloride erosion and freeze–thaw cycling, which has a certain reference significance for the design and application of ancient masonry building repair materials in complex environments.

Green-reinforced Sedimentary Silt with Natural Curaua Fiber

ABSTRACT Lime and cement as traditional binders need to be reduced in soil stabilization to avoid carbon dioxide emissions. Infrastructure development like paved structures, buildings, foundations, and dams involves exhaustive use of natural resources and serious concern for the environment. Using natural fibers as reinforced soil is a green-novel technique that improves soil properties such as strength, deformation, and expansion. Thus, this paper advances the performance of soil reinforcement using natural fiber. Natural Curauá fiber was used to improve unconfined compressive strength (qu), splitting tensile strength (qt), shear direct, and deformation of sedimentary silt in southern Brazil. By studying strength properties, 0.50% fiber and a length of 6 mm were selected as an optimum percentage and optimum length, respectively. For direct shear tests, the increase in strength at low confining stresses is proportional to the increase in fiber content and fiber length. By natural biodegradation of fiber, expanded polystyrene (EPS)-based treatment was employed, influencing a reduction of 10% in water absorption of fiber and increasing fiber’s tensile strength by 5%. Finally, the results demonstrate that natural fiber is a friendly-environmental alternative to enhance soil properties by applying rammed earth and some short-use earthworks in green constructions.

Analysis of Water Absorption of Different Natural Fibers

The demand for natural fibers has always been high due to their unique characteristics like strength, lightweight, availability, bio-degradability, etc. In every phase of life, from clothing to technical textiles, natural fibers are used. Water absorption of fibers is considered really important in many aspects, e.g., Sportech, Medtech, Geotech, etc. This work analyses water absorption of raw and alkali-treated cotton, arecas, pineapple leaves, and banana fibers. Fibers were scoured with different concentrations of alkali (2, 4, 6 gm/L NaOH), washed and neutralized with the dilute acetic acid solution, then dried. Later on, the fiber samples were immersed into distilled water, and water absorption percentages of the fibers were determined every 10 minutes within 1 hour in total. It appeared that at untreated conditions, the areca fiber has the highest water absorption capacity compared to the other fibers. Alkali-treated cotton shows the highest water absorption, and areca fibers show approximately 60% water absorption of cotton.

Surface Modifications of Oil Palm Mesocarp Fiber by Superheated Steam, Alkali, and Superheated Steam-Alkali for Biocomposite Applications

In this work, surface modifications of oil palm mesocarp fiber were carried out by using superheated steam, alkali, and consecutive superheated steam-alkali treatments, aiming at modification of fiber’s surface for biocomposite applications. The chemical compositions of fiber were modified after treatments as validated by chemical analysis and Fourier transform infrared spectroscopy. The treated fibers under microscopy observation showed relatively clean, rough, and textured surfaces due to the elimination of impurities and hemicellulose. The crystallinity index and thermal stability of treated fibers were relatively higher than that of untreated fiber as determined by X-ray diffraction and thermogravimetric analyses, respectively. A reduction in water absorption of fiber after treatments was also noted. These results indicated those treatments were effective in modifying the chemical compositions and microstructure of fiber. The treatments also increased the crystallinity and thermal stability, as well as reduced the hygroscopicity of fiber. Those treatments could increase the suitability of fiber to be used in the development of biocomposites.

Investigating the efficiency of textile fog-collectors on the basis of fiber parameters

The increasing demand of water in mankind necessitates the need to consider supplementary sources of water. Fortunately, under favorable topographical and atmospheric conditions, water can be collected from fog. Small water droplets appear on the surface of solid objects when fog precipitates on them. So, to some extent, fog can be utilized for relieving water shortage by employing water-collecting systems known as fog collectors that collect water from fog and the moisture present in air. Most of the fog collectors that have been used around the world are made up of polymers and textile materials. The main purpose of this study is, therefore, to investigate some physical fiber parameters influencing the efficiency of textile fog collectors. Consequently, several kinds of fibrous materials in the forms of yarn and/or fabric were investigated. Thus, it was statistically found that water collection efficiency is affected by parameters like fiber–water absorption, specific heat capacity of the material, and the existence of sites for holding moisture on the surface of the materials. In this respect, the effect of contact angle between threads within a fabric structure was investigated on the performance of textile fog collectors. This concept was performed using Eriksson’s model, which is a mathematical model.