Halloysite nanotubes as a stabilizer: fabrication of thermally expandable microcapsules via Pickering suspension polymerization

Modification of Hollow Expanded Microspheres with Superior Thermal Insulation Properties and Their Applications

Thermally expandable microspheres (TEMs) are hollow polymeric particles in which a blowing gas has been encapsulated. This property makes them excellent for thermal insulation applications, such as lightweight fillers. This study has developed a viable technology for further improving thermal insulation properties in the field that needs excellent thermal insulation of textile fabrics. The ATO/TEMs composites were designed and prepared to reduce sunlight radiation by the charge gravity method. The test results showed that the ATO-coated TEMs effectively block thermal radiation from sunlight. The temperature difference between ATO/TEMs treated cotton and the uncoated cotton fabric was 9 °C, and the thermal conductivity coatings were 0.0432 W/m⋅K. The UPF value of ATO/TEMs (ILs) coated cotton fabric is 440, significantly higher than pure cotton. This approach can provide insight into the design of high-performance solar insulation composite structures.

Synthesis of high-temperature thermally expandable microcapsules and their effects on foaming quality and surface quality of foamed ABS materials

In this paper, acrylonitrile and hydroxypropyl acrylate are used as the binary polymerization monomers, and isooctane is used as the foaming agent to prepare high-temperature thermally expandable microcapsules. Analysis of the effect of blowing agent and crosslinking agent on the expansion properties of high-temperature thermally expandable microcapsules, the effects of foaming agent azodicarbonamide (ADCA) and micro-expansion capsule on the surface quality and foaming quality of foamed acrylonitrile–butadiene–styrene (ABS) products were investigated. The foamed product prepared by the high-temperature microcapsule has a good surface quality, the gloss is 52.3, the cell is not easily deformed, and the volume fraction is 4%; the foamed ABS/ADCA material has poor cell uniformity, the cell is easily deformed, the volume fraction is 6.5%, the surface quality is poor, and the gloss is only 8.7.

Surface-Coated Thermally Expandable Microspheres with a Composite of Polydisperse Graphene Oxide Sheets

Surface-modified thermally expandable microcapsules (TEMs) hold potential for applications in various fields. In this work, we discussed the possible surface coating mechanism and reported the properties of TEMs coated with polyaniline (PANI) and polydisperse graphene oxide sheets (ionic liquid-graphene oxide hybrid nanomaterial (ILs-GO)). The surface coating of PANI/ ILs-GO increased the corresponding particle size and its distribution range. The morphologies analyzed by scanning electron microscopy indicated that no interfacial gap was observed between the microspheres ink and substrate layer during the substrate application. The thermal properties were determined by thermogravimetric and differential thermal analyses. The addition of ILs-GO to the polyaniline coating significantly improved the thermal expansion and thermal conductivity of the microcapsules. The evaporation of hexane present in the core of TEMs was not prevented by the coating of PANI/ ILs-GO. The printing application of TEMs showed excellent adaptability to various flexible substrates with great 3D appearance. By incorporating a flame retardant agent into TEMs coated by PANI/ILs-GO, finally, these TEMs also demonstrated a great flame retardant ability. We expect that these TEM-coated PANI/ ILs-GO are likely to have the potential to improve the functional properties for various applications.

Formation mechanism of thermally expandable microspheres of PMMA encapsulating NaHCO3 and ethanol via thermally induced phase separation

The formation mechanism of TEMs via TIPS was investigated. It was supported by calculation, the effect of quench rate and stirring speed.