Porous thermal insulation materials (PTIMs) are a class of materials characterized by low thermal conductivity, low bulk density and high porosity. The low thermal conductivity of the gas enclosed in their pores allows them to achieve efficient thermal insulation, and are they among the most widely used and effective materials in thermal insulation material systems. Among the PTIMs, polyurethane foam (PUF) stands out as particularly promising. Its appeal comes from its multiple beneficial features, such as low density, low thermal conductivity and superior mechanical properties. Such attributes have propelled its broad application across domains encompassing construction, heterogeneous chemical equipment, water conservation and hydropower, and the aviation and aerospace fields. First, this article outlines the structure and properties of porous thermal insulation PUF materials. Next, it explores the methods of preparing porous thermal insulation PUF materials, evaluating the associated advantages and disadvantages of each technique. Following this, the mechanical properties, thermal conductivity, thermal stability, and flame-retardant characteristics of porous thermal insulation PUF materials are characterized. Lastly, the article provides insight into the prospective development trends pertaining to porous thermal insulation PUF materials.
Thermal conductivity and latent heat are crucial performance parameters for phase change materials (PCMs) in thermal energy storage. To enhance the thermal performance of PCMs, with the help of graphene oxide (GO) acting as a dispersing agent, well-defined hybrid graphene aerogels (HGAs) with a three-dimensional (3D) porous structure were successfully synthesized by hydrothermal reaction of GO and graphene nanoplatelets (GNPs). GNPs, dispersing uniformly along the interconnecting graphene network, acted as thermal conductive fillers and supporting materials. Palmitic acid (PA) was impregnated into the HGA by vacuum forces. It was found that the thermal conductivity of the PA/HGA was enhanced without compromising heat storage capacity. Compared with PA, the PA/HGA with 4.2 wt% GNPs exhibited enhanced thermal conductivity of 2.1 W/mK and high latent heat of 206.2 J/g simultaneously. The PA/HGA with good thermal performance has potential applications in thermal energy storage.
Antifouling substances play a crucial role in inhibiting fouling and adhesion due to their broad-spectrum and non-toxic advantages. Nevertheless, the excessive release of the antifouling agents shortens the service life of the antifouling coating. In this study, we investigated the antifouling performance of an ethanol extract from the root of Stellera chamaejasme (Sc) through algal adhesion experiments. The interaction between Sc and algae (Chlorella and Dunaliella tertiolecta) was further studied by using a UV spectrophotometer. Then, Sc was encapsulated with polydopamine (PDA) microcapsules to prepare Sc@SiO2@PDA microcapsules by the template method. The release behavior of Sc@SiO2@PDA under different pH conditions was investigated. The result demonstrates that the interaction between Sc and algae belongs to single static quenching, and the Sc@SiO2@PDA microcapsules exhibit good antifouling performance against Chlorella and Dunaliella tertiolecta. This work will provide guiding significance for the development of eco-friendly marine antifouling coatings.