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HighlightsThis review delves into the intricate relationship between thermal models, function-oriented design principles, and practical applications in personal radiative thermal management (PRTM).It provides an in-depth discussion on design strategies for radiative cooling, heating, and dual-mode modulating textiles, offering practical insights for application.It offers a thorough examination of the prospects and challenges of PRTM textiles, proposing potential solutions and future directions for the field.Maintaining thermal comfort within the human body is crucial for optimal health and overall well-being. By merely broadening the set-point of indoor temperatures, we could significantly slash energy usage in building heating, ventilation, and air-conditioning systems. In recent years, there has been a surge in advancements in personal thermal management (PTM), aiming to regulate heat and moisture transfer within our immediate surroundings, clothing, and skin. The advent of PTM is driven by the rapid development in nano/micro-materials and energy science and engineering. An emerging research area in PTM is personal radiative thermal management (PRTM), which demonstrates immense potential with its high radiative heat transfer efficiency and ease of regulation. However, it is less taken into account in traditional textiles, and there currently lies a gap in our knowledge and understanding of PRTM. In this review, we aim to present a thorough analysis of advanced textile materials and technologies for PRTM. Specifically, we will introduce and discuss the underlying radiation heat transfer mechanisms, fabrication methods of textiles, and various indoor/outdoor applications in light of their different regulation functionalities, including radiative cooling, radiative heating, and dual-mode thermoregulation. Furthermore, we will shine a light on the current hurdles, propose potential strategies, and delve into future technology trends for PRTM with an emphasis on functionalities and applications.

Artificial recapitulation of the hierarchy of natural protein fibers is crucial to providing strategies for developing advanced fibrous materials. However, it is challenging due to the complexity of the natural environment. Inspired by the liquid crystalline spinning of spiders, we report the development of natural silk-like hierarchical fibers, with bundles of nanofibrils aligned in their long-axis direction, by self-assembly of crystallized silk fibroin (SF) droplets. The formation of self-assembled SF fibers is a process of coalesced droplets sprouting to form a branched fibrous network, which is similar to the development of capillaries in our body. The as-assembled hierarchical SF fibers are highly bioactive and can significantly enhance the spreading and growth of human umbilical vein endothelial cells compared to the natural SF fibers. This work could help to understand the natural silk spinning process of spiders and provides a strategy for design and development of advanced fibrous biomaterials for various applications. The creation of silk fibres using bioinspired approaches is of interest for biomaterials development. Here, the authors report on the creation of mimetic hierarchical silk fibres by the rotational self-assembly of silk fibroin droplets and demonstrate the creation of bioactive silk materials.

In this article, we have demonstrated a novel needleless electrospinning of PVA nanofibers by using a conical metal wire‐coil as spinneret. Multiple polymer jets were observed to generate on the coil surface. Up to 70 kV electric voltage can be applied to this needleless electrospinning nozzle without causing “corona discharge.” Compared with conventional needle electrospinning, this needleless electrospinning system produced finer nanofibers on a much larger scale, and the fiber processing ability showed a much greater dependence on the applied voltage. Finite element calculation indicates that the electric field intensity profiles for the two systems are also quite different. This novel concept of using wire coil as the electrospinning nozzle will contribute to the further development of new large‐scale needleless electrospinning system for nanofiber production. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

The inorganic and organic nanocomposites have enticed wide interest in the field of polymer-based composite systems to augment their physiochemical properties like mechanical strength and electrical conductivity. Achieving interfacial interaction between inorganic filler and polymer matrix is a recurring challenge, which has significant implications for mechanical properties of nanocomposites. In this context, the effect of “interfacial zone” on structural and thermal attributes of the melt blended pristine polycarbonate and polycarbonate (PC) decorated fumed silica nanocomposite have been examined from ambient temperature to the glass transition temperature. Thermomechanical characterization and in-situ temperature assisted small angle X-ray scattering technique (SAXS) were used for contemplating quantitative and qualitative molecular dynamics of developed nanocomposites. Though, the FT-IR spectra have demonstrated some extent of interaction between inorganic and organic groups of composite, the reduced glass transition temperature and storage modulus was ascertained in DMA as well as in DSC, which has been further confirmed by in-situ temperature assisted SAXS. It is envisioned that the utilization of in-situ SAXS in addition to the thermomechanical analysis will render the qualitative and quantitative details about the interfacial zone and its effect on thermal and mechanical properties of nanocomposite at varying temperature conditions.

Polypropylene (PP) nanofibres have been electrospun from molten PP using a needleless melt-electrospinning setup containing a rotary metal disc spinneret. The influence of the disc spinneret (e.g., disc material and diameter), operating parameters (e.g., applied voltage, spinning distance), and a cationic surfactant on the fibre formation and average fibre diameter were examined. It was shown that the metal material used for making the disc spinneret had a significant effect on the fibre formation. Although the applied voltage had little effect on the fibre diameter, the spinning distance affected the fibre diameter considerably, with shorter spinning distance resulting in finer fibres. When a small amount of cationic surfactant (dodecyl trimethyl ammonium bromide) was added to the PP melt for melt-electrospinning, the fibre diameter was reduced considerably. The finest fibres produced from this system were 400±290 nm. This novel melt-electrospinning setup may provide a continuous and efficient method to produce PP nanofibres.

Four different cellulose nanofibers samples were prepared from northern bleached softwood kraft fibers. Fiber diameter distributions were measured from SEM images. Fiber aspect ratios ranging from 84 to 146 were estimated from fiber suspension sedimentation measurements. Three samples had heterogeneous distributions of fiber diameters, while one sample was more homogeneous. Sheet forming experiments using filters with pores ranging from 150 to 5 μm showed that the samples with a heterogeneous distribution of fiber dimensions could be easily formed into sheets at 0.2% initial solids concentration with all filter openings. On the other hand, sheets could only be formed from the homogenous sample by using 0.5% or more initial solids content and a lower applied vacuum and smaller filter openings. The forming data and estimated aspect ratios show reasonable agreement with the predictions of the crowding number and percolation theories for the connectivity and rigidity thresholds for fiber suspensions.

Inorganic/organic nanofillers have been extensively exploited to impart thermal stability to polymer nanocomposite via various strategies that can endure structural changes when exposed a wide range of thermal environment during their application. In this abstraction, we have utilized temperature assisted in-situ small angle X-ray scattering (SAXS) to examine the structural orientation distribution of inorganic/organic nanofiller octa phenyl substituted polyhedral oligomeric silsesquioxane (Ph-POSS) in Polycarbonate (PC) matrix from ambient temperature to 180 °C. A constant interval of 30 °C with the heating rate of 3 °C/min was utilized to guise the temperature below and above the glass transition temperature of PC followed by thermal gravimetric, HRTEM, FESEM and hydrophobic analysis at ambient temperature. The HRTEM images of Ph-POSS nano unit demonstrated hyperrectangular structure, while FESEM image of the developed nano composite rendered separated phase containing flocculated and overlapped stacking of POSS units in the PC matrix. The phase separation in polymer nanocomposite was further substantiated by thermodynamic interaction parameter (χ) and mixing energy (E mix ) gleaned via Accelrys Materials studio. The SAXS spectra has demonstrated duplex peak at higher scattering vector region, postulated as a primary and secondary segregated POSS domain and followed by abundance of secondary peak with temperature augmentation.

A facile and original method was developed to fabricate flexible conductive yarns using cotton roving and carbon nanotubes (CNTs). The CNTs were assembled to cotton roving and then wrapped around by fibers through twisting during ring spinning. The obtained CNT treated cotton yarns (CNT-CYs) showed great electrical conductivity and durability properties. The CNT-CYs were analyzed using scanning electron microscopy and Raman scattering spectroscopy. The electrical conductivity, mechanical property and flexibility of CNT-CYs were investigated. The results show that electrical resistance of roving, twist and linear density of yarn affect the electrical conductivity of CNT-CYs. Combination with CNTs increased the breaking strength of cotton yarns. The electrical resistance of CNT-CYs was relatively stable during stretching and human motions. Moreover, no obvious changes in electrical resistance were found after CNT-CYs were bent 100 times. The CNT-CYs possessed good durability to repeated washing and abrasion.

In this work, high efficiency and multifunctional poly(vinyl alcohol‐co‐ethylene) nanofiber, Ag particle, and polypropylene (PP) meltblown nonwoven substrate composite (NF@Ag) air filters by a simple spray coating method and subsequent UV irradiation treatment are demonstrated. The water vapor transmission rate of the NF@Ag‐4 air filter is 4753.36 ± 316.75 g/(m2 d), which is higher than that of commercial PP nonwoven (4240.71 ± 354.36 g/(m2 d)). It is can be explained that the NF@Ag‐4 air filter is a Janus structure with asymmetric wettability, which enhances moisture permeability, thereby improving comfort while wearing. The NF@Ag‐2 air filter exhibits high filtration efficiency (95.80 ± 0.89%) and relatively low pressure drop (122.00 ± 1.73 Pa) without relying on the electrostatic adsorption effect. The resulting NF@Ag air filters display excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, photothermal disinfection, and thermal insulation performance. Furthermore, the as‐prepared NF@Ag air filters can be simply patterned and designed as respiration monitoring sensors to precisely detect the respiratory activity and health of the human being. Therefore, it is believed that these multifunctional air filters will have good potential for applications in the removal of particular matters and breathable wearable electronic devices. The multifunctional poly(vinyl alcohol‐co‐ethylene) nanofiber, Ag particle, and polypropylene (PP) nonwoven composite (NF@Ag) air filters prepared by a spray coating method followed by UV irradiation treatment. The obtained NF@Ag air filters have excellent filtration performance, moisture permeability, antibacterial properties, photothermal and insulation performance, and can be patterned as respiratory sensor to monitor the respiratory activity.

Graphene, multi-wall carbon nanotube (MWCNT) and fine boron nitride (BN) particles were separately applied with a resin onto a cotton fabric, and the effect of the thin composite coatings on the thermal conductive property, air permeability, wettability and color appearance of the cotton fabric was examined. The existence of the fillers within the coating layer increased the thermal conductivity of the coated cotton fabric. At the same coating content, the increase in fabric thermal conductivity was in the order of graphene > BN > MWCNT, ranging from 132 % to 842 % (based on pure cotton fabric). The coating led to 73 %, 69 % and 64 % reduction in air permeability when it respectively contained 50.0 wt% graphene, BN and MWCNTs. The graphene and MWCNT treated fabrics had a black appearance, but the coating had almost no influence on the fabric hydrophilicity. The BN coating made cotton fabric surface hydrophobic, with little change in fabric color.