Crystals
·
2022
·Vol. 12
·期 3
·351
·
IF 2.67
Wendi Yu,Lu Yang,Jing Zhao,Hongjie Luo
The transport and crystallization processes of chromogenic 5.0% CuSO4solution in the supporting body and coarse plaster of simulated wall painting samples were observed. A scanning electron microscope a and self-designed double-layer surface contact internal pressure method were used to test, respectively, the micro-morphologies of salt crystals in different regions and the micro-forces on the contact surfaces during the spread and crystallization of water and salt solution. The results demonstrate that the salt crystals formed by the CuSO4solution on the surface of the simulated wall painting showed two different shapes: a salt belt formed by clustered crystals, and a layer of salt crust. The difference was speculated to be related to the crystals’ growth conditions. The destructive effect of salt solution and salt crystals on wall paintings manifested itself by weakening the connectivity between different materials, and changing the volume and morphology of the wall paintings. Using the double-layer surface contact internal pressure method, the forces generated by the salt solution and salt crystals on the simulated wall paintings were demonstrated to be adsorption force, expansion force generated by the crystals’ precipitation and growth, and suction force resulting from water loss and the shrinkage of crystals. The expansion force and suction force were not in a stable state, resulting in the contact surfaces continuously bending and stretching. Compared with pure water, salt solution can aggravate damage to the stability of wall paintings. This analysis of the transport, crystallization and micro-forces of a chromogenic salt solution in simulated wall painting samples can provide a scientific basis for studying the general patterns of damage caused by soluble salt to wall paintings during its transport and crystallization, and provide insight that can further the protection of cultural relics.Keywords:chromogenic salt solution;simulated wall painting;transport and crystallization;micro-force
研究领域:
文物保护
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 13
·4549
·
IF 3.4
Chuiyuan Kong,Bin Zhou,Rongxin Guo,Feng Yan,Rui Wang,Changxi Tang
Based on the physical and chemical properties of red sandstone (RS), RS is used to produce composite cementitious materials. The flowability, mechanical strength, and micromechanics of a red sandstone–cement binary cementitious material (RS-OPC) were investigated as functions of the amount of RS replacing the cement (OPC). Additionally, the feasibility of producing red sandstone–phosphogypsum–cement composite materials (RS-PG-OPC) using the phosphogypsum (PG)- enhanced volcanic ash activity of RS was investigated. The products of hydration and microstructures of RS-OPC and RS-PG-OPC were analyzed by XRD, FTIR, TG-DTG, and SEM. RS enhanced the flowability of RS-OPC relative to the unmodified cement slurry but lowered its mechanical strength, according to the experiments. When the quantity of OPC replaced was greater than 25%, the compressive strength after 28 days was substantially reduced, with a maximum reduction of 78.8% (RS-60). The microscopic mechanism of RS-OPC suggested that the active SiO2in the RS can react with Ca(OH)2to produce C-S-H but can only utilize small quantities of Ca(OH)2, confirming the low volcanic ash activity of RS. RS was responsible for dilution and filling. The incorporation of 5% PG into RS-PG-OPC slowed the hydration process compared with RS-OPC without PG but also increased the flowability and aided in the later development of the mechanical strength. This was primarily because the addition of PG provided the system with sufficient Ca2+and SO42−to react with [Al(OH)6]3−to form ettringite (AFt), therefore accelerating the dissolution of Al3+in RS to generate more AFt and C-(A)-S-H gels. To some extent, this excites the volcanic ash of RS. Therefore, if there is an abundance of waste RS in the region and a lack of other auxiliary cementitious materials, a sufficient quantity of PG and a finely powdered waste RS component can be used to replace cementitious materials prepared with OPC to reduce the mining of raw OPC materials.Keywords:red sandstone;phosphogypsum;flowability;mechanical strength;micromechanics;volcanic ash activity
研究领域:
建筑材料学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
VIEW
·
2022
·Vol. 3
·期 5
·20220031
·
IF 0
Shenglong Wang,Boling Lan,Yuyu Gao,Yanting Xie,Hanyu He,Da Xiong,Guo Tian,Tao Yang,Junfeng Huang,Yong Ao,Yue Sun,Weiqing Yang,Weili Deng
MXenes have received tremendous attention for flexible electronics owing to their excellent conductivity, water dispersibility, and mechanical flexibility. However, the sediment from the MXene production process is usually discarded as trash, resulting in low utilization. Here, we present a flexible pressure sensor that enables micro-force sensing and efficient utilization of MXene by confining MXene trash among structured MXene electrodes. Benefiting from the synergistic effect of both the confined micro-conical structure and easily changeable space of MXene trash, the as-designed device can detect extremely subtle pressure of 2.9 Pa, deliver a high sensitivity over 4.08 kPa −1 , and exhibit a remarkably fast response time (7 ms). These properties make it suitable for monitoring weak force signals from human wrist pulse and even for detecting dynamic responses associated with acoustic waves. This work provides a reference for the versatile and efficient application of MXene in the same device, showing great potential for sustainable production of next-generation wearable smart electronics.
研究领域:
材料科学
·
柔性电子
·
传感器技术
✓ 已验证
产品关联
DOI
COMPOSITES SCIENCE AND TECHNOLOGY
·
2017
·
IF 4.873
Hao-hao Ren,Dong-xia Xu,Guang-ming Yan,Gang Zhang,Xiao-jun Wang,Sheng-ru Long,Jie Yang
The aim of this study was synthesis of the polyphenylene sulfide (PPS) containing carboxyl unit and investigation of the effect of modified PPS used as compatibilizer on the interfacial micromechanical properties of carbon fiber (CF) reinforced PPS composites. A series of copoly(1,4-phenylene sulfide)-poly(2,5-phenylene sulfide acid) (PPS-COOH)s containing different proportions of carboxyl units in the side chain were synthesized by the reaction of dihalogenated monomer and sodium sulfide via nucleophilic substitution polymerization under high pressure. According to the results of FT-IR, DSC , TGA , mechanical test and contact angle test , all of the copolymers were found to have analogous structure and improved hydrophilic property comparing with neat PPS. There was a good physical compatibility between the modified PPS and the pure PPS. The microbond test (measuring apparent interfacial shear strength (τ app ) of the composite) and scanning electron microscopy (SEM) also showed that the optimized PPS-COOH (7.5) can be used to improve the micro-mechanical properties and interfacial bonding between CF and PPS matrix. The maximum τ app of 10%PPS-COOH (7.5)/PPS/CF composite was 49.1 MPa, which had increased 36.0% comparing with that of the pure PPS/CF composite (36.1 MPa).
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·Vol. 45
·期 10
·9196-9208
·
IF 4.8
Ningmin Duan,Yong Li,Zhenyu Shi,Jilai Wang,Chengpeng Zhang,Xuefeng Tang,Guilong Wang
Nowadays, it is still a huge challenge to predict the interlaminar shear strength (ILSS) of three-phase carbon fiber reinforced polymer (CFRP). Herein, the three-phase micromechanical model is innovatively constructed to predict the ILSS of CFRP, and the conception of new matrix is proposed by establishing a connection between the third phase and the matrix, which effectively solves the problem of uneven distribution of the third phase. To verify the accuracy of the micromechanical model, the Ti 3 C 2 T x MXene/CFf/epoxy composites were fabricated by the co-blending, layer-by-layer assembly and hot-pressing technology, and the finite element simulation analysis was also performed based on the micromechanical model. The results show that the micromechanical model possesses high accuracy. Specifically, the experimental value of ILSS of the composite with 1 wt% Ti 3 C 2 T x MXene content is 52.12 MPa, and the errors of simulation value (56.64 MPa) and theoretical prediction value (58.69 MPa) are 8.67% and 12.61% MPa, respectively. Besides, the detailed fracture mechanism of the composite is presented based on the fracture morphology and simulation results. It is believed that this work will provide more possibilities for the prediction of the interlaminar shear performance of three-phase composites. Highlights A novel micromechanical model is used to predict the ILSS of three-phase composite. The accuracy of the micromechanical model is verified by simulation and experiment. The main failure form of the Ti 3 C 2 T x MXene/CFf/epoxy composite is matrix broken. The micromechanical model of the three-phase composites has high accuracy.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Mingyuan Yan,Xudong Cheng,Lunlun Gong,Zhiyi Lun,Pan He,Long Shi,Chenjie Liu,Yuelei Pan
Owing to excellent high temperature resistance, high porosity and light weight, SiC aerogels possess great application prospects in thermal insulation and adsorption. However, poor mechanical properties of SiC aerogels, such as brittleness and non-bendability, hinder its application; it is still a challenge to improve and regulate the mechanical properties of SiC aerogels. Here, for the first time, we propose a micromechanical design strategy to prepare flexible SiC nanowire/mullite fiber composite aerogels (SMCAs). By optimizing the aspect ratio of the skeleton fibers to regulate the stress state of microstructures, the maximum compressive stress of that SMCAs could bear can be tuned systematically from 1.2 kPa to 1254.8 kPa, spanning 3 orders of magnitude. More importantly, thanks to its micromechanical design, SMCAs can withstand up to 80% compression deformation and up to 90° bending deformation. The present work provides a new idea for the regulation of mechanical properties of ceramic aerogels.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）