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Biodegradable oil absorbing materials have attracted extensive attention in dealing with oil spill pollution. To develop more excellent oleophilic oil sorbent, the combination of tannic acid and ferrous sulfate was employed to treat the renewable and biodegradable natural kapok fiber. The as-prepared kapok showed superhydrophobic characteristics with high water contact for the formation of tannic acid and ferrous ion complex on kapok surface, which was confirmed by scanning electron microscopy observation and infrared spectroscopy and X-ray diffraction analysis. The preparation process of the modified kapok fiber was optimized. When the sodium chlorite pretreated kapok fiber was firstly treated with 4.25 g/l tannic acid and subsequently immersed in 4.25 g/l tannic acid and 6.25 g/l ferrous sulfate mixture at 60 °C for 15 min, the asprepared kapok fiber presented the best oil absorption capacity and hydrophobicity (water contact angle 150.7 °). The treated kapok had good adsorption capacity for oils and organic solvents, 48.2, 41.6, 53.4, 52.8, 49.2, 41.2 g/g for vegetable oil, diesel oil, silicone oil, carbon tetrachloride, DMF and n-hexane, respectively. In addition, the tannic acid and ferrous sulfate treated kapok was recycled for six times through simple mechanical squeezing, and showed good oil-water separation performance oil, indicating its potential application in the removal of spilled oil on water. [ABSTRACT FROM AUTHOR]

A novel structural composite yarn was fabricated by periodically forcing filaments with harmonic migrations to enhance the cooperativity between filaments and staple fibers. The geometrical principle of yarn structure variations caused by harmonic migrations of filaments was theoretically analyzed, then demonstrated the influences of filament's positions on different shapes of the composite spinning-triangle zone. Further, the novel structural composite yarn structure was compared to the seven models of composite yarns which were established with different filament's positions, showing a varied filament helical structure to capture and then lock internal and external staple fibers, distinguishing that other composite yarns in literature. Then, a synergetic eccentric device was employed to oscillate two filaments to conduct confirmatory tests. The online observations of the dynamic spinning-triangle zone were technically applied to evaluate the filaments' harmonic migrations. Furthermore, the yarn structural variations were caused by various geometrical configurations. Experimental results exhibited that the novel structural composite yarn had relatively fewer hairiness, medium irregularity, and strength after comparisons with other composite yarns. Altogether, the cyclically harmonic migrations of filaments were promising as an efficient and novel method for control the configurations between filaments and staple fibers. [ABSTRACT FROM AUTHOR]

Bonding among fibers is critical to developing a high strength fabric. Chemical adhesive (polyvinyl butyral, abbreviated as PVB) can improve the bonding between fibers to improve yarn strength to the required level. However, retaining the fabric strength after abrasion and washing without the loss of chemical adhesive is challenging. In this study, a novel method has been applied to intra-layer PVB-paste spinning to improve yarn strength. The forming mechanism and PVB flow/fibers compaction model of PVB-paste spun yarn were analyzed. The optimum process parameters of intra-layer PVB-paste spinning combined with orthogonal experiments were established, which maximally increased the binding force between the filament and staple fibers to improve the yarn strength. Moreover, in comparison to original yarn, PVB-paste spun yarn strength can be increased up to 32.3 % in the best case. Therefore, the yarn strength could be improved via intra-layer PVB-paste spinning. Meanwhile, the tearing and breaking strength of PVB-paste fabric were approximately 27.8 % and 7.2 % more than those of cotton fabric, respectively. Additionally, the fabric made by that yarn also maintains good strength performance during abrasion and washing, while also having good hand-feel characteristics. Overall, the successful manufacture of these PVB-paste fabric should promote the development of high-performance fabric. [ABSTRACT FROM AUTHOR]

One substantial plant waste, lotus leave was fabricated into lotus leave powder with different diameters by ball milling. The surface morphology, chemical composition, particle size, porosity parameters, crystal structure, and wettability of lotus leaf powders (LLPs) were analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), laser particle size analysis, N2 adsorption/desorption, X-ray diffraction (XRD) analysis, and water contact angle (WCA) analysis, respectively. The results showed that the micro- and nanoscale waxy papilla structures on the surface of the lotus leaf were gradually destroyed by mechanical forces along with extended balling time. Accompanied re-exposing of -OH affluent cellulose nanocrystals (CNCs) was proved by HR-TEM, XRD, and FTIR. FTIR also revealed a hydroxyl to carboxyl transition on the surface of CNCs. Both the re-exposure of CNCs and thereof chemical structure transition after ball milling made the LLP a good candidate for pollutant adsorbent for dye, formaldehyde, and heavy metal ions. [ABSTRACT FROM AUTHOR]