No abstract

Purpose The purpose of this paper is to study the influence of different factors on mud performance, find the best conditions and synthesize a new type of anti-collapse drilling polymer mud with higher stability. The anti-collapse mechanism of drilling polymer mud was also suggested. Design/methodology/approach Exploring the influence of different molecular weight thickeners, filtrate reducers, soda ash addition and film-forming components on the mud performance, so as to obtain the best ratio of anti-collapse drilling polymer mud. Findings The results show that the use of vegetable glue, sulfonate copolymer and vegetable fiber powder can synthesize a high-viscosity, high-stability, collapse-resistant mud. When the mass ratio of vegetable fiber powder: vegetable glue: sulfonate copolymer is 40:1:2, the mud viscosity is 21.2 s, the fluid loss in 30 min is only 12.5 mL, and the mud film thickness is 1.5 mm, which is one ideal anti-collapse polymer mud. Originality/value Compared with ordinary polymer mud and bentonite mud, this anti-collapse polymer mud not only uses vegetable glue instead of traditional tackifiers but also effectively uses vegetable fiber powder produced from waste wood, which is environmentally friendly and highly stable specialty. It can effectively improve the safety and quality of construction during drilling in water-sensitive geology.

No abstract

As an extremely promising new class of materials, MXenes (two-dimensional layered materials) have attracted much interest and become a research hotspot in many fields. Owing to the typical layered structure, excellent electronic performance, it can be used as co-catalysts to recombine other photocatalytic materials to enhance the separation of photo-generated charges, inhibit the rapid recombination of charges, and finally convert solar energy into chemical energy. MXenes, which exhibit extraordinary catalytic activity in photocatalytic reactions, are increasingly being widely used as co-catalysts. This article summarizes and discusses two photocatalytic reactions with MXenes as co-catalysts, the dehydrogenation reaction (HER) and the CO2 reduction reaction (CO2RR), as well as their physical and chemical properties, preparation and synthesis methods, and the latest research progress. Summarized related applications and photocatalysis principles. Finally, the prospects and expectations of MXenes in photocatalytic applications are presented.

The preparation of homogeneous polymer mud has an important role in the underground diaphragm wall engineering. A homogeneous polymer mud of underground diaphragm wall was synthesized by a simple compounding method in this work. The prepared samples analyzed by infrared spectroscopy. The effects of different film-forming auxiliaries, thickening components and pH on the homogeneity of the diaphragm wall were studied through the measurement of viscosity and specific gravity. The results showed that the prepared polymer mud of underground diaphragm wall had the best homogeneity and stable viscosity in the following conditions: in the pH range of 8-10, the addition of bentonite as a filming auxiliary with 5 kg of puffing agent per ton, and the dosage of vegetable gum was about 10-20 kg in every 100 m3 of mud. The possible reasons of affected homogeneity were suggested.