Carbon nanofiber (CNF), as one of the most important members of carbon fibers, has been investigated in both fundamental scientific research and practical applications. CNF composites are able to be applied as promising materials in many fields, such as electrical devices, electrode materials for batteries and supercapacitors and as sensors. In these applications, the electrical conductivity is always the first priority need to be considered. In fact, the electrical property of CNF composites largely counts on the dispersion and percolation status of CNFs in matrix materials. In this review, the electrical transport phenomenon of CNF composites is systematically summarized based on percolation theory. The effects of the aspect ratio, percolation backbone structure and fractal characteristics of CNFs and the non-universality of the percolation critical exponents on the electrical properties are systematically reviewed. Apart from the electrical property, the thermal conductivity and mechanical properties of CNF composites are briefly reviewed, as well. In addition, the preparation methods of CNFs, including catalytic chemical vapor deposition growth and electrospinning, and the preparation methods of CNF composites, including the melt mixing and solution process, are briefly introduced. Finally, their applications as sensors and electrode materials are described in this review article.

The most recent studies on the applications of nanostructured carbon materials, including carbon nanotubes, carbon nanofibers, and graphene oxides, in constructions are presented. First, the preparation of nanostructured carbon/infrastructure material composites is summarized. This part is mainly focused on how the nanostructured carbon materials were mixed with cementitious or asphalt matrix to realize a good dispersion condition. Several methods, including high speed melting mixing, surface treatment, and aqueous solution with surfactants and sonication, were introduced. Second, the applications of the carbon nanostructured materials in constructions such as mechanical reinforcement, self‐sensing detectors, self‐heating element for deicing, and electromagnetic shielding component were systematically reviewed. This paper not only helps the readers understand the preparation process of the carbon nanostructured materials/infrastructure material composites but also sheds some light on the state‐of‐the‐art applications of carbon nanostructured materials in constructions.

The urban heat island (UHI) effect has a significantly negative impact on the living environment in urban areas. Asphalt pavement is one of the most widely used infrastructures that absorbs solar energy, which leads to the UHI effect and premature failure. As a result, cool pavement technology has been rapidly developed in recent years to mitigate the UHI effect originating from asphalt pavement. Although several outstanding review articles have analyzed previous studies on cool pavement technologies, very few review articles have focused on how to design and expand cool pavement technology from a materials perspective. In this mini-review article, the theoretical and practical factors of the solar reflective coatings and phase-change materials, which are significantly dependent on the design of new materials, have been summarized. The main challenges and potential problem-solving ideas have been presented. In a cool pavement, the solar reflective coatings are composed of epoxy resin or acrylic polymer matrix filled with solar reflective nanoparticles, such as TiO₂, SiO₂, ZnO, Al₂O₃, or Fe₂O₃. The main challenges of the solar reflective coatings are the spalling of the coating polymers from the asphalt pavement surface and the dispersion of the solar reflective nanoparticle in the polymer matrix. Most importantly, it is critical to harmonize the balance between the bonding strength, aging rate, solar reflectance, curing requirements, mechanical properties, and durability of the solar reflective coating. For the nanofillers, the cost of the filler materials, the balance between UV, visible light, and near-infrared reflectance and the dispersion status of the nanofillers in the polymer matrix are the primary factors that must be concerned. For the phase-change materials (PCMs), the interaction between the asphalt and the PCMs, the decomposition of the PCMs, the toxicity of the PCMs, the distribution status of the PCMs in the asphalt matrix, and the cost are the main factors that have to be considered in constructions. This review article can not only provide basic knowledge for the development of new solar reflective pavement materials but also serve as a guide for practical applications of cool pavement in the field.

The phenomenon of rutting is one of the most serious problems on asphalt pavements. Decreasing the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, a nano-sized-particles-filled polymer composite was developed as an overlay to reflect solar energy and decrease the surface temperature of asphalt pavements. The overlay was composed of acrylic or epoxy resin filled with nano TiO₂ or nano TiNO₂. The solar reflection of the nanoparticle-filled polymers was tested, and the results showed that solar reflection effectiveness of the TiO₂/acrylic composite reached the highest value. The results of outdoor temperature tests indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements by about 10°C when the pavement temperature is about 60°C.