Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties

Abstract

Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

Flexible Phase Change Material Fiber: A Simple Route to Thermal Energy Control Textiles

“…In our case of PEG1000-filled fibers, the PCM formed a continuous phase, giving the material the chance to crystalize as a whole, and thus to form a perfect crystal, which results in higher enthalpy of melting and crystallization. However, the phase change process is also influenced by intermolecular incidents like physical entanglement, as has been observed in fibers melt-electro spun from mixtures of polyurethane (PU) PCM and polymethyl methacrylate (PMMA) [ 54 ]. Here, the actual phase-change enthalpies of the mixtures were considerably lower than the corresponding theoretical values, most likely because the PU-PCM molecules did not have enough time to form well-defined crystallites upon cooling, since the surrounding PMMA molecules limited their movement during the crystallization process [ 54 ].…”

Reaction-Spun Transparent Silica Aerogel Fibers

“…Thermal protection in harsh environments is of fundamental importance for human beings, and materials have been developed from hides, bark and leaves in ancient times to natural fibers which are obtainable from animal, vegetable, or mineral sources for centuries, and now to various synthetic fibers and fabrics. , Recent achievements on synthetic fibers provide more exciting opportunities toward better thermal protection and management. For example, hollow fibers, − biomimetic porous fibers, , and ultrafine fibers have shown advantages in thermal insulation over natural fibers, whereas the demand for more efficient thermal insulation fibers is still growing fast. For such a purpose, the forthcoming fibers should be as porous as possible, with an ultralow mass density and large porosity.…”

Photoluminescent Composites of Lanthanide-Based Nanocrystal-Functionalized Cellulose Fibers for Anticounterfeiting Applications

“…Anticounterfeiting materials containing trivalent lanthanide rare earth ions have been extensively applied in anticounterfeiting for its excellent luminescence intensity and free from harmful radiation. − The functional matrix was made of the rare earth luminescent materials and film-forming polymers, combined with functional additives by a melt-spinning process. − The film-forming polymers used such as nylon, polypropylene, polyethylene, polyvinyl chloride, and polyester had ostensibly led to higher resource exhausting and environmental pollution caused by petroleum waste . Moreover, the poor thermal stability of rare earth-doped nanocrystals largely restricted their application when melt-spinning with polymers at high temperatures. , …”