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This study aims to evaluate the thermal performance of phase change materials (PCMs) microcapsules (MCs) attached using SiO₂ microspheres and investigate the thermal regulation effect on the coated denim fabric.

The PCM microcapsule was prepared by in situ polymerization using a mixture of solid paraffin and butyl stearate as core material (CM) and methyl methacrylate as a monomer. The SiO₂ microparticles were attached to the outer layer of the membrane to enhance the thermal performance of MCs. The morphology, chemical structure, latent heat storage and thermal resistance of MCs were characterized. PCM MCs were coated on the denim fabric and thermo-gravimetric analysis was conducted; thermal insulation and thermal infrared imaging performance of the coated fabrics were also investigated.

The diameters of SiO₂ particles and PCMs MCs were 300-500 nm and 1 μm, respectively. SiO₂ was wrapped on single-wall PCMs MCs with the mass ratio of 1:5. With the addition of SiO₂, the phase transition temperature range of MCs increased from 34°C to 39°C, and the endothermic and exothermic latent heat decreased by 5.35 J/g and 10.07 J/g, respectively. The degradation rate of MCs was significantly slowed down at high temperature. The denim fabric coated with MCs revealed thermal regulation property. After absorbing heat, the MCs slowed down the rate of heat loss and extended the heat release time.

The phase transition temperature of the composite CM was wide, and the latent heat storage was reduced. The addition of SiO₂ particles can significantly slow down the rate of heat loss, but it further reduces the latent heat storage performance.

The method developed provided a simple and practical solution to improve the thermal regulation performance of fabrics.

The method of adjusting the phase transition temperature range of the composite CM is novel and many applications could be found in preparation of PCMs and thermal management.

The present study provides a comprehensive review of the advancements in five active heating modes for cold-proof clothing as of 2021. It aims to evaluate the current state of research for each heating mode and identify their limitations. Further, the study provides insights into the optimization of intelligent temperature control algorithms and design considerations for intelligent cold-proof clothing.

This article presents a classification of active heating systems based on five different heating principles: electric heating system, solar heating system, phase-change material (PCM) heating system, chemical heating system and fluid/air heating system. The systems are analyzed and evaluated in terms of heating principle, research advancement, scientific challenges and application potential in the field of cold-proof clothing.

The rational utilization of active heating modes enhances the thermal efficiency of cold-proof clothing, resulting in enhanced cold-resistance and reduced volume and weight. Despite progress in the development of the five prevalent heating modes, particularly with regard to the improvement and advancement of heating materials, the current integration of heating systems with cold-proof clothing is limited to the torso and limbs, lacking consideration of the thermal physiological requirements of the human body. Additionally, the heating modes of each system tend to be uniform and lack differentiation to meet the varying cold protection needs of various body parts.

The effective application of multiple heating modes helps the human body to maintain a constant body temperature and thermal equilibrium in a cold environment. The research of heating mode is the basis for realizing the temperature control of cold-proof clothing and provides an effective guarantee for the future development of the intelligent algorithms for temperature control of non-uniform heating of body segments.

The integration of multiple heating modes ensures the maintenance of a constant body temperature and thermal balance for the wearer in cold environments. The research of heating modes forms the foundation for the temperature regulation of cold-proof clothing and lays the groundwork for the development of intelligent algorithms for non-uniform heating control of different body segments.

The present article systematically reviews five active heating modes suitable for use in cold-proof clothing and offers guidance for the selection of heating systems in future smart cold-proof clothing. Furthermore, the findings of this research provide a basis for future research on non-uniform heating modes that are aligned with the thermal physiological needs of the human body, thus contributing to the development of cold-proof clothing that is better suited to meet the thermal needs of the human body.

The purpose of this paper is to investigate the thermo-physiological comfort of male business garments made of common textiles, as well as business clothing that contains phase change materials (PCMs) as a lining or outerwear material. In view of the fact that people wear business clothing throughout the whole day in different environmental conditions, this study investigate the effect of PCMs incorporated in male business clothing systems on the thermo-physiological comfort of the wearer under different cold environmental conditions.

The influence of particular business garments on the thermo-physiological comfort of the wearer during different physical activities and cold environmental temperatures was determined experimentally with the help of study participants, as a change of two physiological parameters: mean skin temperature and heart rate. A questionnaire and an assessment scale were also used in order to evaluate the wearer’s subjective feeling of comfort. In this investigation, all tests with study participants were performed under artificially created environmental conditions in a climate chamber at different cold environmental temperatures ranging from 10°C to −5°C with increments of 5°C, and different physical activities that simulate as closely as possible real life activities such as sitting and walking.

The results of the performed research work show that PCMs provide a small temporary thermal effect that is reflected in small increases or decreases in mean skin temperature during changes in activity. Furthermore, it was concluded that the small effect of PCMs in business clothing systems on the thermo-physiological comfort of the wearer in a cold environment, which is shown as a change of mean skin temperature when subjects walk on a treadmill and subsequently move to a sitting position, should not be ignored in a cold environment where low skin temperatures were measured.

The results of this study demonstrate that the physiological parameters of thermo-physiological comfort, in combination with subjective evaluation, provide valuable information for textile and clothing manufactures as well as scientists and engineers involved in the design and development of new products with thermal comfort as a quality criterion.

The investigation shows that different environmental conditions, activity levels and thermal properties of clothing systems have a considerable impact on the physiological parameters of the subjects and subjective assessment of thermal comfort in a cold environment, and that PCMs incorporated in business clothing systems provide a small temporary thermal effect that is reflected in small increases or decreases in mean skin temperature during changes in activity, such as when subjects walk on a treadmill and subsequently move to a sitting position.

The purpose of this paper is to investigate thermoregulation properties of different composite phase change materials (PCMs), which could be used in the high temperature environmental conditions to protect human body against the extra heat flow.

Three kinds of composite PCM samples were prepared using the selected pure PCMs, including n-hexadecane, n-octadecane and n-eicosane. The DSC experiment was performed to get the samples’ phase change temperature range and enthalpy. The simulated high temperature experiments were performed using human arms in three different high temperature conditions (40°C, 45°C, 50°C), and the skin temperature variation curves varying with time were obtained. Then a comprehensive index TGP was introduced from the curves and calculated to evaluate the thermoregulation properties of different composite PCM samples comprehensively.

Results show that the composite PCM samples could provide much help to the high temperature human body. It could decrease the skin temperature quickly in a short time and it will not cause the over-cooling phenomenon. Comparing with other two composite PCM samples, the thermoregulation properties of the n-hexadecane and n-eicosane composite PCM is the best.

Using the n-hexadecane and n-eicosane composite PCM may provide people with better protection against the high temperature conditions, which is significative for the manufacture of functional thermoregulating textiles, garments or equipments.

Fabrics with photothermal conversion functions were developed based on the introduction of shape stable composite phase change materials (CPCMs).

Acidified single-walled carbon nanotubes (SWCNTs) were selected as support material to prepare CPCMs with n-octadecane to improve the thermal conductivity and shape stability. The CPCMs were finished onto the surface of cotton fabric through the coating and screen-printing method. The chemical properties of CPCMs were characterized by Fourier transform infrared spectrometer, XRD and differential scanning calorimetry (DSC). The shape stability and thermal conductivity were also evaluated. In addition, the photothermal conversion and temperature-regulating performance of the finished fabrics were analyzed.

When the addition amount of acidified SWCNTs are 14% to the mass of n-octadecane, the best shape stability of CPCMs is obtained. DSC analysis shows that the latent heat energy storage of CPCMs is as high as 183.1 J/g. The thermal conductivity is increased by 84.4% compared with that of n-octadecane. The temperature-regulating fabrics coated with CPCMs have good photothermal conversion properties.

CPCMs with high latent heat properties are applied to the fabric surface through screen printing technology, which not only gives the fabric the photothermal conversion performance but also reflects the design of personalized patterns.

CPCMs and polydimethylsiloxane (PDMS) are mixed to make printing paste and printed cotton fabric with temperature-regulating functional is developed.

SWCNTs and n-octadecane are composited to prepare CPCMs with excellent thermal properties, which can be mixed with PDMS to make printing paste without adding other pastes. The fabric is screen-printed to obtain a personalized pattern and can be given a thermoregulatory function.

The purpose of this paper is to prepare microencapsulated phase change materials (PCMs) and apply them to cotton and wool fabrics for developing thermo-regulating fabrics.

Microencapsulated n-hexadecane and n-octadecane with poly(methylmethacrylate-co-2-hydroxy ethyl methacrylate) shell was prepared. Microcapsules were fabricated using oil-in-water emulsion polymerization method. Their chemical structure, microstructure, thermal energy storage properties and thermal stability were analyzed by Fourier-transform infrared spectroscopy, polarized light microscope, differential scanning calorimeter and thermogravimetric analyzer, respectively. The mean particle size was tested by a particle sized instrument. The microcapsules were applied to the wool and cotton fabrics using pad-dry-cure method. The thermo-regulating property of the fabrics was evaluated using the T-History test. The distribution and durability of the microcapsules on the fabrics was investigated with scanning electron microscopy.

Spherical microcapsules with p(MMA-co-HEMA) shell and n-alkane core have been produced successfully. n-hexadecane in microcapsule solidifies at 14.8−15.6°C with the latent heat of 65.6−129.8 J/g and melts at 16.7−16.9°C with the latent heat of 67.6−136.9 J/g. Microencapsulated n-octadecane solidifies at 25.8−26.3°C with the latent heat of 74.1−106.2 J/g and melts at 26.8−27.4°C with the latent heat of 80.3−113.4 J/g. The microcapsules have enough thermal stability to the temperature of 150°C that was applied during the fixation of microcapsules on the fabric. The thermo-regulating effect of the microcapsule-incorporated fabrics has been proved by the T-history test.

PCM microcapsules with p(MMA-co-HEMA) shell and n-hexadecane and n-octadecane core have been produced and their usage to produce thermo-regulating textiles have been proved. To determine the thermo-regulating property of the fabrics treated with these new PCM microcapsules, a T-History system has been designed.

The paper aims to provide an overview of the area of smart textiles.

The paper describes and discusses new and developing materials and technologies used in the textile industries.

Significant progress has been achieved in the area of technical textiles. Fibres, yarns, fabrics and other structures with added‐value functionality have been successfully developed for technical and/or high performance end‐uses. The basic building blocks are already in place in the field of smart textiles and clothing.

As progress in science and engineering research advances, and as the gap between designers and scientists narrows, the area of smart clothing is likely to keep on expanding for the foreseeable future. Growth is predicted to occur in two distinct directions: performance‐driven smart clothing and fashion‐driven smart clothing. There are challenges that have to be addressed.

The paper provides information of value to those interested in the future directions of the textile industry.

In order to characterize the temperature regulating ability of fabrics containing phase change material (PCM), the test instrument has been designed and built.

To assess temperature regulating ability, temperature regulating factor (TRF) is determined. TRF is defined by Hittle as a quotient of the amplitude of the temperature variation of the hot plate and the amplitude of the heat flux variation divided by the steady state heat resistance of the fabric.

The test instrument presented here is intended to be used for testing steady state and transient state characteristics of the apparel fabrics containing the PCMs.

This test instrument can be used in quality control during the manufacture of fabrics containing PCMs. TRF can be used in clothing industry to establish the criteria for comfort parameters of textiles.

The instrument can provide information for the fabric and garment designers and be useful in quality control during the manufacture of fabrics with the microPCMs. The TRF can be used in the clothing industry to establish the criteria for the comfort parameters of textiles.

This study aims to manufacture cotton fabric with thermal regulation performance by using the composite phase change material (CPCM) prepared by coating paraffin doped with expanded graphite (EG), and the thermal effect of the fabric material was evaluated and characterized.

EG/paraffin CPCM with shape stability and enhanced thermal conductivity were prepared by the impregnation method and then finished on the surface of cotton fabric with coating technology. The microstructure, crystal structure, chemical composition, latent heat property and thermal conductivity were analyzed by scanning electron microscope, x-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimeter and thermal constant analyzer. The photo-thermal effect of the coated fabric was studied by a thermal infrared imager.

CPCM prepared with a mass ratio of EG to paraffin of 1:8 showed excellent shape stability and low paraffin leakage rate. The latent heat of the CPCM was 51.6201 J/g and the thermal conductivity coefficient was increased by 11.4 times compared with the mixed paraffin. After the CPCM was coated on the surface of the cotton fabric, the light-to-heat conversion rate of the C-EG/PA3 sample was improved by 86.32% compared with the original fabric. In addition, the coated fabric showed excellent thermal stability and heat storage performance in the thermal cycling test.

EG can improve the shape stability and thermal conductivity of paraffin but will reduce the latent heat energy.

The method developed provided a simple and practical solution to improving the thermal regulation performance of fabrics.

Combining paraffin wax with fabrics in a composite way is innovative and has certain applicability in improving the thermal properties of fabrics.

The purpose of this work was to express a facile method to fabricate microcapsules containing linseed oil with melamine-urea-formaldehyde (MUF) shell in the presence of polyvinylpyrrolidone (PVP) as an emulsifier. These microcapsules may be used in self-healing coating formulations.

In this work, different types of PVP (i.e., PVP with different molecular weights or K values) were used as emulsifiers and colloid protectors to encapsulate linseed oil in an MUF shell. Moreover, the effect of agitation rate on the morphology of the microcapsules was investigated. Microcapsule morphology and particle size distribution were evaluated using optical microscopy and scanning electron microscopy. Thermal studies were performed using a thermo-gravimetric analysis technique and chemical structure of materials was characterized by using Fourier transform infrared analysis.

In this work, microcapsules with a regular spherical shape and a shell thickness of about 330 nm were fabricated. The results revealed that the use of PVP in the fabrication of MUF could facilitate the synthesis process by eliminating the necessity of pH control during the reaction. In fact, the pH of the reaction media must be precisely controlled in conventional processes. The yield of microencapsulation was found to be 86.5 per cent when a high molecular weight of PVP (PVP K-90) was used. It was also found that the surface morphology of microcapsules became smoother when PVP K-90 was used. The results showed that the surface roughness and the average particle size decreased with an increase in stirring intensity. Mean diameter of the prepared microcapsules ranged from 34 to 346 μmin for various synthesis conditions.

This work is limited to the encapsulation of a hydrophobic liquid (such as linseed oil) by an in situ polymerisation of amino resins.

The presented results can be used by researchers (in academia and industry) who are working in the field of fabrication microcapsules, in various applications such as pharmaceuticals, electrophoretic displays, textiles, carbonless copy papers, cosmetics, printing and self-healing materials.

PVP is considered as an environmentally friendly emulsifier. Therefore, this process is less harmful to the environment. In addition, the prepared microcapsules may be used in self-healing coatings, which helps in reducing maintenance costs for buildings and steel structures.

Ethylene maleic anhydride and styrene maleic anhydride are usually used as emulsifiers in conventional methods for the preparation of amino resin microcapsules. These methods require an intensive and precise pH control to obtain favourable microcapsules, while in the present research, a facile method was used to fabricate MUF microcapsules containing linseed oil without needing any pH control during the reaction.