Search

The increasing demand for sustainable alternatives to fossil-based products has prompted research into the valorization of agricultural residues. This study investigated the production of high-quality dissolving pulp from wheat straw using an organosolv process. The primary objectives were to evaluate the feasibility of using organic acids for pulping, optimize the process conditions, and assess the quality of the resulting dissolving pulp. Wheat straw was treated using mixtures of formic acid (FA) and acetic acid (AA) at various ratios (35:65 and 65:35 FA:AA), employing both steaming and immersion methods. The pulp underwent alkaline extraction, followed by a two-stage bleaching process consisting of chlorine dioxide (ClO2) treatment and catalytic hydrogen peroxide (H2O2) bleaching with CuSO4 as an activator. The resulting alpha-cellulose samples were characterized using various analytical techniques, including viscosity measurement, FTIR spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results demonstrated that high-quality dissolving pulp could be successfully produced from wheat straw using the organosolv process. The highest alpha-cellulose content (92%) and yield (58.16%) were achieved using a formic acid to acetic acid ratio of 35:65 v/v. The steaming method generally produced pulp with superior properties compared to the immersion method. FTIR and XRD analyses confirmed the high purity of the obtained dissolving pulp, while FESEM revealed well-defined, individual cellulose fibers with a high degree of defibrillation. Thermal analysis showed good thermal stability of the produced dissolving pulp. This study highlights the potential of wheat straw as a viable raw material for producing high-quality dissolving pulp using an organosolv process. [ABSTRACT FROM AUTHOR]

Materials with stimulus-responsive wettability are attracting increasing attention because of their potential applications in oil/water separation and oil spill remediation. Herein, a pH-responsive filter paper was rapidly fabricated by initially forming a complex between TiO2 and octadecylamine, followed by immersion in an ethanolic solution of SiO2 nanoparticles. The resultant filter paper exhibited superhydrophobicity and superoleophilicity in air when the solution pH was greater than 6.0, whereas it became superhydrophilic and superoleophobic when the solution pH was less than 2.0. The treated filter paper was used for the controllable separation of complex oil/water/oil ternary mixtures, demonstrating its strong response to pH changes. The pH-responsive filter paper effectively separated both immiscible oil/water mixtures and different kinds of oil-in-water emulsions with separation efficiencies exceeding 99%. The durability of the pH-responsive filter paper was demonstrated by its ability to maintain a separation efficiency of around 99%, even after 25 cycles of separating a typical emulsion of tetrachloromethane in water. The developed approach has the potential to provide innovative smart materials for the treatment of oil-contaminated wastewater. [ABSTRACT FROM AUTHOR]

Superhydrophobic cotton fabrics have received much attention in recent years. They have been constructed usually by lowering surface energy and increasing surface roughness. Because of the significant environmental harm caused by fluorine-containing reagents, difficult preparation techniques, and low wear resistance, finding a simple approach to prepare a fluorine-free, wear-resistant, strongly sticky superhydrophobic cotton fabric remains a challenge. In this study, we describe a fluorine-free superhydrophobic cotton fabric using the simple preparation approach of immersion, which creates nanoscale siloxane aggregates dispersible in organic solvents. The modified cotton fabrics are characterized by scanning electron microscopy, fourier-transform infrared, and energy dispersive spectroscopy. Excellent superhydrophobicity (ultrahigh water contact angle is 165.2° and sliding angle is 7.2° as well as excellent self-cleaning properties) has been easily applied to cotton fabrics. Superhydrophobic cotton fabrics also have good anti-fouling properties for many common types of liquids, such as milk, coffee, cola, etc. It has been established that these waterproof coatings exhibit outstanding mechanical endurance against water impact, abrasion, and laundering. Superhydrophobic fabrics have a wide range of possible uses due to their readily available coating materials, simple application technique, and strong mechanical endurance. [ABSTRACT FROM AUTHOR]