Qiong Su

There are some drawbacks such as the propagation and spread of bacteria and viruses during the use of normal paper. Therefore, this work designed a starch styrene-acrylic antibacterial emulsion for improving the paper properties. The modified antimicrobial monomer was prepared by the subject-object recognition of β-cyclodextrin with hydrophobic modified titanium dioxide. The antibacterial performance of prepared emulsion was tested by Escherichia coli, Staphylococcus aureus. And the mechanical properties of the modified paper were measured according to the national standards. The results showed that the antibacterial emulsion has excellent comprehensive performance with the viscosity of 1750 mPa·s, the inhibition ring diameter of 11.82 mm, the good chemical stability and storage stability. Therefore, the proposed cationic starch styrene-acrylic antibacterial emulsion has promising applications in paper surface modification.

Glue-free wheat straw-based fiberboard has the advantages of excellent performance, such as no formaldehyde release, being renewable, and being degradable, which presents a novel approach to enhance the utilization value of straw and protect the environment.. In this study, wheat straw was first pre-treated to remove impurities such as wax and silica contained in wheat straw by a 2% sodium hydroxide solution, and further modified by carboxymethylation and acylation to obtain wheat straw fiberboard raw materials with different functional properties. Then, H2O2 was used as the initiator, and the wheat straw fiberboard raw materials were hot-pressed at 100 °C and 140 kg/cm² to prepare glue-free wheat strawbased fiberboard with the bending strength of 95.43 MPa, the impact toughness of 2.68 kJ/m², the tensile strength of 9.2 MPa, the elastic modulus of 1773.03 MPa, and the hardness of 81D. The performances of the prepared glue-free wheat straw-based fiberboard with zero formaldehyde have surpassed that of the general glue-free board and have the potential to replace wood board.

A Lewis acid-catalyzed phosphinoylation and halogenation of α,β-unsaturated ketones to synthesize γ-halo allylic phosphonates is described. This transformation consists of a phospha-Michael addition, unimolecular elimination dehydration cascade reaction for the introduction of versatile groups (–P(O)R₃R₄ and –X) in the resulting γ-substituted allylic phosphonates with high regio- and stereoselectivity.

It is very important to choose a suitable method and catalyst to treat coking wastewater. In this study, Fe–Ce–Al/MMT catalysts with different Fe/Ce molar ratios were prepared, characterized by XRD, SEM, and N₂ adsorption/desorption, and treated with coking wastewater. The results showed that the optimal Fe–Ce–Al/MMT catalyst with a molar ratio of Fe/Ce of 7/3 has larger interlayer spacing, specific surface area, and pore volume. Based on the composition analysis of real coking wastewater and the study of phenol simulated wastewater, the response surface test of the best catalyst for real coking wastewater was carried out, and the results are as follows: initial pH 3.46, H₂O₂ dosage 19.02 mL/L, Fe²⁺ dosage 5475.39 mL/L, reaction temperature 60 °C, and reaction time 248.14 min. Under these conditions, the COD removal rate was 86.23%.

Theoretical and experimental investigations have shown that biochar, following KOH activation, enhances the efficiency of NO removal. Similarly, NaOH activation also improves NO removal efficiency, although the underlying mechanism remains unclear. In this study, zigzag configurations were employed as biochar models. Density functional theory (DFT) was utilized to examine how Li and Na single adsorption and OH co-adsorption affect the reaction pathways of NO reduction on the biochar surface. The rate constants for all reaction-determining steps (RDSs) within a temperature range of 200 to 1000 K were calculated using conventional transition state theory (TST). The results indicate a decrease in the activation energy for NO reduction reactions on biochar when activated by Li and Na adsorption, thus highlighting their beneficial role in NO reduction. Compared to the case with Na activation, Li-activated biochar exhibited superior performance in terms of the NO elimination rate. Furthermore, upon the adsorption of the OH functional group onto the Li-decorated and Na-decorated biochar models (LiOH-decorated and NaOH-decorated chars), the RDS energy barriers were higher than those of Li and Na single adsorption but easily overcome, suggesting effective NO reduction. In conclusion, Li-decorated biochar showed the highest reactivity due to its low RDS barrier and exothermic reaction on the surface.

High-nitrogen stainless steels, which are developed by replacing nickel with nitrogen, have been widely applied in manufacturing wear parts in mechanical engineering. In this study, the tribocorrosion performance of a ferritic high-nitrogen bearing stainless steel (40Cr15Mo2VN) under acetic acid solution with a pH of 3.0 was investigated under different loads ranging from 25 N to 125 N. Quantitative calculations indicated that pure mechanical wear was the predominant cause of material degradation, while the corrosion-accelerated wear component also played a crucial role. The material loss induced by both tribocorrosion and mechanical wear increased with increasing load, leading to severe delamination at sliding surfaces and larger wear debris.

The interfacial mechanism has always been a concern for 3-aminopropyltriethoxysilane (APTES)-grafted palygorskite (PAL). In this research, the mechanism of graft modification for grafting of APTES to the surface of PAL (100) was studied using density functional theory (DFT) calculation. The results illustrated that different grafting states of the APTES influence the inter- and intramolecular interactions between APTES/PAL (100), which are reflected in the electronic structures. For single-, double-, and three-toothed state APTES-PAL (100), the charge transfer rates from the PAL (100) surface to APTES were 0.68, 1.02, and 0.77 e, respectively. The binding energy results show that PAL (100) modification performance in the double-tooth state is the best compared to the other states, with the lowest value of −181.91 kJ/mol. The double-toothed state has lower barrier energy (94.69, 63.11, and 153.67 kJ/mol) during the modification process. This study offers theoretical insights into the chemical modification of the PAL (100) surface using APTES coupling agents, and can provide a guide for practical applications.

A novel acylhydrazone-based self-assembled supramolecular gel for ultrasensitive alternating fluorescence detection of Fe³⁺ and H₂PO₄⁻.