Experimental investigation of nano/microencapsulated phase change material emulsion based building wall paint for solar thermal energy storage

Polyurethane/n-Octadecane Phase-Change Microcapsules via Emulsion Interfacial Polymerization: The Effect of Paraffin Loading on Capsule Shell Formation and Latent Heat Storage Properties

Organic phase-change materials (PCMs) hold promise in developing advanced thermoregulation and responsive energy systems owing to their high latent heat capacity and thermal reliability. However, organic PCMs are prone to leakages in the liquid state and, thus, are hardly applicable in their pristine form. Herein, we encapsulated organic PCM n-Octadecane into polyurethane capsules via polymerization of commercially available polymethylene polyphenylene isocyanate and polyethylene glycol at the interface oil-in-water emulsion and studied how various n-Octadecane feeding affected the shell formation, capsule structure, and latent heat storage properties. The successful shell polymerization and encapsulation of n-Octadecane dissolved in the oil core was verified by confocal microscopy and Fourier-transform infrared spectroscopy. The mean capsule size varied from 9.4 to 16.7 µm while the shell was found to reduce in thickness from 460 to 220 nm as the n-Octadecane feeding increased. Conversely, the latent heat storage capacity increased from 50 to 132 J/g corresponding to the growth in actual n-Octadecane content from 25% to 67% as revealed by differential scanning calorimetry. The actual n-Octadecane content increased non-linearly along with the n-Octadecane feeding and reached a plateau at 66-67% corresponded to 3.44-3.69 core-to-monomer ratio. Finally, the capsules with the reasonable combination of structural and thermal properties were evaluated as a thermoregulating additive to a commercially available paint.

Microencapsulation of polymeric phase change materials (MPCM) for thermal energy storage in industrial coating applications

In recent years, energy has become an important factor in overall development. Most of the energy comes from fossil fuels which are nonrenewable and harmful to our environment. It has become important to develop new application technologies that utilize thermal energy storage (TES) technology. Energy storage technology based on PCMs is a cutting-edge research area with a wide range of potential applications. But the biggest problem of phase change material is its leakage problem, for that the researchers have set up a solution i.e., the microencapsulation techniques. This paper gives an overview of the synthesis of (MPCM) microencapsulated phase change material by using different methodologies and their applications in industrial coatings. Corrosion is the biggest problem in industrial coatings which reduces the working time span and overall performance of the coatings. The incorporation of the micro-PCMs in industrial coatings increases workability as well as the overall performance of the coatings. This review covers the use of MPCM in various industrial coating applications, challenges, and their future directions are also discussed.

Controllable Fabrication and Oil-Water Separation Properties of Polyethylene Terephthaloyl-Ethylenediamine-IPN-poly(N-Isopropylacrylamide) Microcapsules

In this paper, we report a microcapsule embedded PNIPAN in P (TPC-EDA) shell and it can be regarded as an interpenetrating polymer network (IPN) structure, which can accelerate the penetration of oily substances at a certain temperature, and the microcapsules are highly monodisperse and dimensionally reproducible. The proposed microcapsules were fabricated in a three-step process. The first step was the optimization of the conditions for preparing oil in water emulsions by microfluidic device. In the second step, monodisperse polyethylene terephthaloyl-ethylenediamine (P(TPC-EDA)) microcapsules were prepared by interfacial polymerization. In the third step, the final microcapsules with poly(N-isopropylacrylamide) (PNIPAM)-based interpenetrating polymer network (IPN) structure in P(TPC-EDA) shells were finished by free radical polymerization. We conducted careful data analysis on the size of the emulsion prepared by microfluidic technology and used a very intuitive functional relationship to show the production characteristics of microfluidics, which is rarely seen in other literatures. The results show that when the IPN-structured system swelled for 6 h, the adsorption capacity of kerosene was the largest, which was promising for water-oil separation or extraction and separation of hydrophobic drugs. Because we used microfluidic technology, the products obtained have good monodispersity and are expected to be produced in large quantities in industry.