Nanodiamond-Modified Microencapsulated Phase-Change Materials with Superhydrophobicity and High Light-to-Thermal Conversion Efficiency

Adsorption of Cu Nanoparticles on Polystyrene-Based Microspheres

Nanoparticle composite microspheres are a versatile material with unique features and wide-ranging applications, including catalysis, biological medicine, and electronic devices. The adsorption behavior of nanoparticles on the surface of microspheres plays a crucial role in determining the further application potentials. The understanding of nanoparticle adsorption behavior on microsphere surfaces is essential for guiding future applications in nanoparticle composite microspheres. In this work, the adsorption behavior of unstable copper nanoparticles (Cu NPs) on polystyrene-based (PS-based) microspheres was investigated. The influence of PS-based microspheres' surface properties and the oxidation degree of Cu NPs were determined. The adsorption mechanism of Cu NPs on PS-based microspheres was analyzed. Furthermore, the amounts and rates of adsorption were examined. It was found that the Cu NPs can be rapidly and firmly adsorbed on the surface of carboxyl-modified polystyrene microspheres. Additionally, precise control over the distribution of Cu NPs on the surface of PS-based microspheres can be achieved by manipulating the solvent's polarity.

Phase Change Composite Microcapsules with Low-Dimensional Thermally Conductive Nanofillers: Preparation, Performance, and Applications

Phase change materials (PCMs) have been extensively utilized in latent thermal energy storage (TES) and thermal management systems to bridge the gap between thermal energy supply and demand in time and space, which have received unprecedented attention in the past few years. To effectively address the undesirable inherent defects of pristine PCMs such as leakage, low thermal conductivity, supercooling, and corrosion, enormous efforts have been dedicated to developing various advanced microencapsulated PCMs (MEPCMs). In particular, the low-dimensional thermally conductive nanofillers with tailorable properties promise numerous opportunities for the preparation of high-performance MEPCMs. In this review, recent advances in this field are systematically summarized to deliver the readers a comprehensive understanding of the significant influence of low-dimensional nanofillers on the properties of various MEPCMs and thus provide meaningful enlightenment for the rational design and multifunction of advanced MEPCMs. The composition and preparation strategies of MEPCMs as well as their thermal management applications are also discussed. Finally, the future perspectives and challenges of low-dimensional thermally conductive nanofillers for constructing high performance MEPCMs are outlined.

Multifunctional Photothermal Phase-Change Superhydrophobic Film with Excellent Light-Thermal Conversion and Thermal-Energy Storage Capability for Anti-icing/De-icing Applications

The accumulation of ice may cause serious safety problems in numerous fields. A photothermal superhydrophobic surface is considered to be useful for preventing ice formation because of its environmentally friendly, energy-saving, and excellent anti-icing/de-icing properties. However, it easily fails to work in the absence of sunlight. To improve its anti-icing property without sunlight irradiation, a multifunctional photothermal phase-change superhydrophobic film (MPPSF) consisting of phase-change microcapsules (PCMs) and carbon nanotubes (CNTs) was fabricated using a facile spraying method. Benefitting from the excellent light-thermal conversion effect of CNTs, the surface temperature could increase from -20 to 130.1 °C within 180 s under 808 nm near-infrared laser irradiation of 1 W/cm², thus realizing high-efficiency de-icing. Meanwhile, a portion of the light-thermal energy was stored in the MPPSF because of the phase change of the PCMs. Without sunlight irradiation, the latent heat of the PCMs was released when the external temperature approached the phase-transition temperature. The synergistic effects of the phase-transition latent heat release and superhydrophobicity allowed the MPPSF to effectively hinder the formation of ice for 10.1 min at -20 °C. Therefore, this MPPSF with outstanding anti-icing and de-icing performances is expected to achieve ice prevention and removal in all-days.

Phase-Change Composites Composed of Silicone Rubber and Pa@SiO2@PDA Double-Shelled Microcapsules with Low Leakage Rate and Improved Mechanical Strength

A kind of silicone rubber (SR)/paraffin (Pa)@silicon dioxide (SiO₂)@polydopamine (PDA) phase-change composite was prepared in this work. The double-shelled Pa@SiO₂@PDA phase-change microcapsules were constructed by oxidative self-polymerization of dopamine (DA) in Tris-HCl buffer solution. The effect of the DA content on the properties of Pa@SiO₂@PDA microcapsules and SR/Pa@SiO₂@PDA composites was researched. Due to the protective effect of SiO₂, PDA layer, and SR matrix, the SR/Pa@SiO₂@PDA composites have good leak-proofing performance, and the leakage rate of SR/Pa@SiO₂@PDA-2 is as low as 0.45%. Phase-change enthalpies of the Pa@SiO₂@PDA microcapsules and SR/Pa@SiO₂@PDA composites are reduced slightly with increasing DA content. Meanwhile, the composites displayed improved mechanical strength. The tensile strength of SR/Pa@SiO₂@PDA-2 can be up to 0.560 MPa, which is 1.85 times higher than the tensile strength of pure SR/Pa@SiO₂ because the interface compatibility between Pa@SiO₂ microcapsules and SR is improved through hydrogen bonding between the abundant groups on the PDA surface and the matrix. Moreover, the rough surface of the PDA-modified microcapsules also enhances the interface interaction through physical "interlocking". The new kind of SR/Pa@SiO₂@PDA composite can be used for thermal management.