International Journal of Microstructure and Materials Properties (6 papers in press)

Special Issue on: Research Progress of Nanomaterials – the Structure and Properties of Nanomaterials

• Life prediction of steel fibre reinforced concrete structures under chloride corrosion  
  by Qunxing Bai 
  Abstract: The prediction error of the lifespan of concrete structures is relatively large, so a method for predicting the lifespan of steel fibre reinforced concrete structures under chloride salt corrosion is proposed. Analyse the mechanism of chloride ion intrusion into steel fibre reinforced concrete structures. Prepare steel fibre reinforced concrete structural specimens, and construct a life prediction function for steel fibre reinforced concrete structures by integrating initial corrosion time, mass loss rate, relative dynamic modulus of elasticity, and corrosion rate. The experimental results show that under low NaCl concentration conditions, the service life of concrete structures can reach 35 years; Quality loss rate of steel fibre reinforced concrete structure under chloride corrosion condition 1 > chloride corrosion condition 2 > chloride corrosion condition 3. The relative dynamic elastic modulus decreases with the increase of NaCl concentration and number of cycles, reaching a minimum of 40 GPa.
  Keywords: chloride corrosion; reinforced concrete structure; diffusion theory; life prediction; steel fibre.
  
  
• The dynamic mechanical properties of nano-SiO2 concrete after freezing and thawing  
  by Tong Shan 
  Abstract: The freeze-thaw cycle will have a significant impact on the mechanical properties of concrete, therefore, research on the dynamic mechanical properties of nano-SiO2 concrete after freeze-thaw is carried out. Firstly, select the materials for the concrete specimen and design the mix ratio for specimen preparation. Secondly, prepare nano-SiO2 concrete specimens and conduct freeze-thaw cycling tests. Finally, the dynamic mechanical properties of nano-SiO2 concrete were studied using mass loss rate, relative elastic modulus, frost resistance durability index, and compressive strength as indicators. The test results show that under the freeze-thaw cycle test of three types of concrete specimens, the mass loss rate of concrete is the lowest, the relative elastic modulus decreases the lowest, the frost resistance durability index is the highest, and the 56d compressive strength is the highest with a 6% nano-SiO2 content.
  Keywords: nano-SiO2 concrete; freeze-thaw cycle; dynamic mechanical properties; compressive strength.
  
  
• Preparation and photocatalytic performance of novel porous nano metal organic skeleton composite material  
  by Hexiang Chen, Chunbao Zhao, Jun Zhang 
  Abstract: In order to enhance the stability and scalability of porous nano metal organic skeleton composites, reduce synthesis costs and environmental impacts, and promote the development of multiple fields such as environmental pollution control and material science. This article mainly focuses on the preparation and photocatalytic performance of novel porous nano metal organic skeleton composite material. Reagents and instruments were selected, and the metal organic framework substrate and TiO2 nanoparticles were synthesised. The TiO2 nanoparticles were embedded into the pores of the metal-organic framework to achieve material preparation. The test results showed that TiO2 was uniformly dispersed on the surface of the composite material, exhibiting both the characteristic peaks of the metal-organic framework material and TiO2, with the highest excitation emission peak at 450 nm. The prepared composite material demonstrated strong adsorption capacity for MB, high photocatalytic efficiency, excellent photocatalytic degradation of RhB, a large amount of hydrogen production through water photolysis.
  Keywords: novel porous nano; metal organic framework; composite material; material preparation; photocatalytic performance.
  
  
• SOC estimation method of SiO2 aerogel power battery pack based on improved Kalman filter  
  by Xueke Li, Yanjie Wu, Yanfen Li 
  Abstract: In order to reduce the SOC estimation error of SiO2 aerogel power battery pack and shorten the estimation time, this study proposes a SOC estimation method of SiO2 aerogel power battery pack based on improved Kalman filter. This method first describes the working principle of SiO2 aerogel power battery pack, and analyses the factors that can affect the SOC estimation of the battery, such as charge discharge ratio, aging degree, self-discharge and operating temperature. Then, the first-order RC equivalent circuit is selected as the basic model, and FFRLS technology is used to identify the relevant parameters of the battery to establish a simulation model of battery dynamic changes. Finally, through the improved Kalman filter algorithm, the SOC state of SiO2 aerogel power battery can be accurately estimated. The experimental results show that this method has lower SOC estimation error, shorter estimation time, and good application performance.
  Keywords: Kalman filtering; SiO2 aerogel power battery pack; SOC estimation.
  
  
• The effect of nano SiO2 content on the application performance of modified recycled concrete  
  by Taotao Dong 
  Abstract: By studying the effect of nano SiO2 content on the application performance of modified recycled concrete, materials for preparing nano SiO2 and modified recycled concrete were selected, and corresponding proportioning schemes were designed to prepare concrete specimens. In the testing of application performance indicators such as compressive strength, splitting tensile strength, shear strength, total cracking area, and water seepage height, it is found that there were significant differences in the application performance of modified recycled concrete under the four nano SiO2 dosages of 0%, 0.5%, 1.0%, and 1.5%. Especially at the 1% nano SiO2 content, concrete specimens exhibit the highest compressive strength, splitting tensile strength, and shear strength, while the total cracking area and water seepage height are also the smallest, with the total cracking area per unit area decreasing to 203.1 mm2. Therefore, the appropriate addition of nano SiO2 can effectively improve the application performance of modified recycled concrete.
  Keywords: nano SiO2; modified recycled concrete; application performance; splitting tensile strength; cracking area.
  
  
• Preparation and mechanical properties of carbon nanotube cement-based composite materials for construction  
  by Shaowei Chen, Yanhua Li 
  Abstract: This study aims to investigate the preparation and mechanical properties of carbon nanotube cement-based composite materials for construction. Firstly, graphene nanosheets (GNP), multi walled carbon nanotubes (CNTs), polycarboxylic acid water reducing agents, and benchmark cement were selected to prepare carbon nanotube cement-based composite materials for construction. Then, the mechanical properties of the prepared specimens were verified. The test results show that when carbon nanotubes are 0.1% and silica fume is 5%, the composite material can achieve the maximum compressive strength (116.5 MPa), and the energy storage capacity of the composite material is increased by 12% compared to cement paste. When 0.1% carbon nanotubes and 10% silica fume are added, the composite material can achieve the maximum flexural strength (11.5 MPa), and the loss factor of the composite material is effectively improved, with a maximum increase of 22.59% compared to cement paste.
  Keywords: polycarboxylic acid water reducing agent; bending strength; mechanical properties; composite materials.