Preparation of shrimp shell powder-PVDF filtration membrane and its application in oil-water separationFang, Xia; Xia, Mengsheng; Chen, Yan
doi: 10.1088/1742-6596/2783/1/012035pmid: N/A
In recent years, the problem of ship-related oily wastewater discharge has escalated due to the growing ship trade. Consequently, the hydrophobic modification of polyvinylidene fluoride (PVDF) membranes has gained significant traction within the oil-water separation technology domain as a potential solution. This study presents a new membrane composed of shrimp shell powder, tannic acid (TA), polyvinyl alcohol (PVA), and PVDF with excellent hydrophilicity and micro-nano porosity. The preparation method is simple, non-toxic, and environmentally friendly. Shrimp shell powder is beneficial to modify the hydrophobic PVDF membrane. The strongly adhesive TA-PVA complex helps to improve the durability of shrimp shell powder in TA-PVA-PVDF membranes. Shrimp shell powder was evenly coated on the PVDF (polyvinylidene difluoride) membrane by vacuum filtration to prepare the TA-PVA-PVDF filter membrane with superhydrophilic-underwater hydrophobicity. The initial efficiency of the emulsified oil-water mixture in the separation experiments reached 99.5%. Furthermore, even after conducting 10 repeated experiments, the separation efficiency remained consistently high at 96.1%.
In-situ growth of MoSe2 on N-doped Ti3C2Tx for electrocatalytic hydrogen evolution in alkaline mediaZhou, Xingliao; Liu, Jinhua; Chen, Jing
doi: 10.1088/1742-6596/2783/1/012033pmid: N/A
Serious environmental contamination and the energy crisis have heightened public desire for new renewable energy sources. Because of its high energy content and non-polluting qualities, hydrogen energy has emerged as a viable alternative to fossil fuels. Currently, high-purity hydrogen is typically produced through water electrolysis. The sensible use of electrocatalysts in this process can significantly minimize power usage in the electrolysis of water, which is of great significance to industrial production. However, the electrocatalyst that is inexpensive, has abundant reserves and performs well has yet to be discovered, severely restricting the promotion and application of hydrogen energy. In this paper, a MoSe2/N-doped Ti3C2TX heterostructure with notable electrocatalytic hydrogen evolution activity in an alkaline environment was fabricated via nitrogen doping and in-situ growth of molybdenum selenide. When the current density is 10 mA·cm-2, its overpotential and Tafel slope are 321.87 mV and 139.97 mV·dec-1, respectively. This work serves as a valuable experimental reference for the development of non-noble metal electrocatalysts based on two-dimensional materials.
Study on the effect of Mg and Ag trace elements on the properties of Al-Cu-Mn alloyZhang, Jiang; Hong, Mengli; Hong, Xiaolu; Lv, Jianjun; Liu, Yongqiang; Chen, Dahui; Peng, Yinjiang
doi: 10.1088/1742-6596/2783/1/012011pmid: N/A
This article introduces the addition of Mg, Ag trace elements, and AlTi5B refiners to the Al-Cu-Mn alloy furnace charge to regulate the size, morphology, and distribution of precipitates, as well as the distribution of particles, to form highly dispersed and thermally stable nanoparticles. A high strength and toughness Al-Cu-Mn-Mg-Ag alloy with fine microstructure and uniform grain distribution is obtained. The experimental results indicate that the addition of Mg, Ag trace elements, and AlTi5B in Al-Cu-Mn alloy can significantly refine α- Al dendrite, the grain size can be refined to 150 μ below m, and the microstructure is more uniform. When the Mg content is 0.2% and Ag content is 0.3%, the T (Al20Cu2Mn3) phase at the grain boundary is significantly increased, and the T phase is in a point-like and discontinuous distribution at the grain boundary. At this time, the comprehensive performance of the alloy is the best (Rm: 431 MPa; RP0.2: 251 MPa; A: 13.2%; hot crack ring width: 20 mm).
Infrared radiation suppression and mechanical properties characterization of aluminum/glass/polysiloxane coatingsQi, Lun; Yuan, Le; Chen, Sixuan; Zhu, Qiyun; Wu, Xueyu
doi: 10.1088/1742-6596/2783/1/012058pmid: N/A
The coatings (polysiloxane, flake aluminum, and glass powder) mechanical and infrared properties were analyzed in detail. The hardness, adhesion, surface roughness, SEM, and infrared thermal imager were used to evaluate the infrared radiation suppression and mechanical performance. The influences of coatings structure (pigment/adhesive ratio, function filler, and solvent content) on infrared emissivity were analyzed through theory and experiment. The coating hardness increased as the temperature increased due to the decomposition of the adhesive. The adhesion analysis showed an “M” type trend due to the functional powder and structure of the coating. Moreover, the coating infrared radiation suppression was also analyzed after thermal and chilling shock resistance.
Significantly improved electrical conductivity and cycling stability of manganese dioxide by poly (3,4-ethylene-dioxythiophene) coatingChai, Penghao; Nie, Yuelin; Bao, Lixia; Peng, Jiong; Li, Xin
doi: 10.1088/1742-6596/2783/1/012046pmid: N/A
Manganese dioxide (MnO2) is widely acknowledged as a prospective pseudocapacitive material aimed at alleviating the issue of low energy density in supercapacitors. Nevertheless, hampered by its intrinsic low conductivity and poor structural stability, MnO2-based energy storage materials often exhibit lower practical capacity in practical applications. During this investigation, the synthesis of MnO2@PEDOT (poly(3,4-ethylenedioxythiophene)) composite materials involved an in-situ oxidative polymerization approach, whereby PEDOT nanowires were integrated onto the MnO2 nanoparticle surface. Notably, the internal configuration of the MnO2@PEDOT composite material demonstrated a high surface area morphology, while the externally entwined PEDOT nanowire layer further expanded the material’s specific surface area. As a result, the MnO2@PEDOT composite material demonstrated a specific capacitance reaching 214 F g-1, a 91% improvement compared to unmodified MnO2. Furthermore, the winding of PEDOT nanowires effectively suppressed the structural disintegration of MnO2. The MnO2@PEDOT composite material exhibited a remarkable improvement in cycling stability, maintaining 81% of its initial capacity after 5000 cycles. The electron-rich PEDOT not only improved the conductivity of the inner MnO2 through electron migration but also prevented MnO2 structural degradation by tightly enveloping it. The outcomes of our study propose a method for constructing MnO2 featuring a structurally stable configuration and a prolonged cycling lifespan, offering valuable insights for designing electrode materials with high cycling stability in supercapacitors.
Numerical simulation research of winding tension system based on hoop residual stress of thick-walled compositeMiao, Yanan; Liu, Xingpeng; Geng, Yuru; Zhang, Min
doi: 10.1088/1742-6596/2783/1/012048pmid: N/A
The forming quality of the composite shell is closely related to the tension system. Nowadays, although there are many studies on the tension system, most of them take the thin-walled composite material forming process derived by the deflection equation as the research object, which is relatively simple. Therefore, due to the limitation of the traditional two-step forming process of winding and curing or the in-situ forming process of winding followed by curing, the product forming efficiency and quality is not high. Moreover, the tension system establishment method based on the existing forming process cannot reflect the variation trend of the temperature field and the coupling law of the temperature-curing degree field during winding. It is difficult to reflect the influence of thermal parameters on winding tension in real-time, resulting in the mismatch between the actual winding tension and the established tension system. Therefore, this paper adopts the heated-mandrel winding process based on winding with curing to establish a tension system model to solve the above problems. The original tension calculation equations are re-derived to establish a winding tension system that considers the variation of stress caused by the temperature field. Finally, the hoop residual stress distribution is simulated to verify the applicability of the established tension system based on the heated-mandrel winding process.
Enhancing anticorrosive properties of low-zinc composite epoxy coatings with graphenePan, Kai; Lin, Yijun; Xi, Zhiwei; Wang, Lijie; Huang, Chunfang; Zhang, Guangzhao
doi: 10.1088/1742-6596/2783/1/012055pmid: N/A
Traditional zinc-rich coatings face challenges such as high zinc powder content, brittle film formation, poor adhesion, high porosity, and low zinc powder utilization. In this study, graphene was introduced into an epoxy coating with a 30% zinc powder content to develop a graphene-modified low-zinc coating with exceptional corrosion resistance and mechanical properties. The primary objective was to determine the optimal graphene addition for enhanced corrosion resistance and mechanical performance. Characterization of the coating included assessing pull-off adhesion, flexibility, impact resistance, saltwater resistance, and resistance to acids and alkalis. Concurrently, the corrosion resistance of coatings was thoroughly examined through electrochemical testing and salt spray experiments. Our findings indicate that the coating demonstrated optimal overall performance with a graphene content of 1%, achieving superior corrosion resistance as well as enhanced physical and mechanical properties.
Synthesized robust and thermal stable zirconia aerogel by using N, N-dimethylformamide as a drying inhibitorHou, Sifan; Sun, Yinjie; Zhang, Kai; Li, Guoqi; Fan, Jinpeng
doi: 10.1088/1742-6596/2783/1/012030pmid: N/A
N, N-dimethylformamide (DMF) is used as a drying inhibitor to prepare ZrO2 aerogels. The properties were investigated and the result reflected that adding DMF can get bulk aerogels with better mechanical strength (0.51 MPa), lower density (0.38 g/cm3), lower thermal conductivity (0.024 W·m-1·K-1), and higher specific surface area (123.46 m2/g) after heat treatment. Its performance as a drying inhibitor is better than that of formamide (FA). It indicates that DMF can be used as a drying inhibitor to prepare zirconia aerogel with excellent thermal stability and mechanical strength.
The penetrating restoration mechanism of reactive polymer on slight crack of asphalt pavementWang, Jie; Yuan, Bo; Yang, Bo; Dang, Jing; Tang, Shutong; Li, Yuanyuan; Chen, Yaohui
doi: 10.1088/1742-6596/2783/1/012063pmid: N/A
To explore the penetrating restoration mechanism of reactive polymer on slight crack (<3 mm) of asphalt pavement, based on the self-developed reactive MMA material, through the combination of viscosity control and micro-analysis methods, the penetration depth of different viscosities of binding materials to micro-crack and microstructure of the preventive maintenance interface were studied. The results show that the penetration depth of the binding material to the micro-crack is positively correlated with the viscosity of the material, and the restoration effect of the micro-crack depends on the fullness of the filling and curing state of the material in the crack. When the filler content is 20%, the penetration depth of the binding material to the micro-crack can reach 1 mm. The penetration depth can be changed through viscosity control, and a full-continuous restoration structure can be obtained. The microstructure of the micro-crack restoration area shows that the penetration enhancement of the polymer seal material to the micro-crack in the pavement includes three processes: penetration, filling, and curing.
Ternary particle composite synergistically enhances the fluidity and dielectric properties of filled thermal conductive epoxy resinLv, Yang; Qiao, Jian; He, Jianfei; Yang, Wei; Wang, Kun; Huang, Shilei; Ma, Huan
doi: 10.1088/1742-6596/2783/1/012013pmid: N/A
Particle-packed epoxy materials are widely used to improve the thermal conductivity of insulation materials. However, the addition of fillers increases the viscosity of the composite which reduces its operability, and is not conducive to the packaging of power electronic equipment such as electric transformers and reactors. Multi-scale particle compounding is one of the effective methods to enhance the co-processing performance of materials by reducing the friction between particles and epoxy matrix while forming an effective thermal conductivity network. Three types of spherical alumina sized around 4 μm, 38 μm, and 125 μm were used as fillers to study the fluidity, thermal conductivity, and dielectric properties of single-filled and ternary compounds. The results showed that the ternary particle composite reduced the viscosity of the precursor by up to 68.8%, achieving a synergistic improvement in operability, thermal conductivity, and electrical performance.