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De-Yi, Wang

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Wang

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De-Yi

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Escuela Politécnica Superior

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2021 - 202426
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Now showing 1 - 10 of 26
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    MXene multi-functionalization of polyrotaxane based PCMs and the applications in electronic devices thermal management.
    (Nano Materials Science, 2024) Yin, Guang-Zhong; López, Alba Marta; Collado, Ignacio; Vázquez López, Antonio; Ao, Xiang; Hobson, Jose; Prolongo, Silvia G.; De-Yi, Wang
    The aim of this work was to improve the thermal conductivity and electromagnetic shielding of the leakage proof phase change materials (PCMs), in which a polyrotaxane (PLR) was used as a support material to encapsulate PEG 1k or PEG 6k and MXene as multi-functional filler. The PCMs can be processed conveniently by a hot press and the PEG 1k containing samples showed excellent flexibility. We conducted a systematic evaluation of the phase transition behavior of the material, thermal conductivity and electromagnetic shielding performance tests. Notably, the PCMs achieved a high enthalpy values (123.9–159.6 ​J/g). The PCMs exhibited an increase of 44.3 ​%, and 137.5 ​% in thermal conductivity values with higher MXene content (5 ​wt%) for PLR-PEG6k and PLR-PEG1k, respectively, and show high shape stability and no leakage during and after phase transition. The introduction of MXene can significantly improve the electromagnetic shielding performance of PCM composites. Typically, higher conductive samples (samples which contain high MXene contents) offer a higher EMI SE shielding, reaching a maximum of 4.67 ​dB at 5.6 ​GHz for PLR-1K-MX5. These improvements solve the main problems of organic PEG based PCMs, thus making PLR-PEG-MXene based PCMs good candidates for thermoregulators of both solid-state disks and smart phone. It is worth pointing out that the sample PLR-1k-MX5 can decrease 4.3 ​°C of the reference temperature during cellphone running. Moreover, the temperature of the protecting sheet in the simulated solid state disk with PCM was significantly lower (showing a decreasing of 7.9 ​°C) compared with the blank sample.
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    Sodium alginate and Chitosan aided design of form-stable Polyrotaxane based phase change materials with ultra-high latent heat.
    (International Journal of Biological Macromolecules, 2022) Yin, Guang-Zhong; Yang, Xiao-Mei; López, Alba Marta; Wang, Mei-Ting; Ye, Wen; Xu, Baoyun; De-Yi, Wang
    We prepared a series of highly porous Polyrotaxane/sodium alginate, and Polyrotaxane/Chitosan foam alloys according to a sustainable pathway by using water as the only solvent. The foam alloys were further used as supporter materials for poly (ethylene glycol) (PEG) encapsulation, to fabricate shape-stable bio-based phase change materials (PCMs). The pore morphology and the internal interface between PEG and foam alloys were characterized by scanning electron microscope (SEM). Due to the good compatibility between foam alloys and PEG, the PCM performed perfect anti-leakage properties. The introduction of sodium alginate or Chitosan ensures the shape stability of the PCMs during the phase transition. The PCMs performed good cycle stability and showed ultra-high latent heat (171.6 J g−1–189.5 J g−1). Finally, we compared the typical indicators of this work with those reported in the literature, and the comparison highlighted that the present PCMs have the significant advantages: high melting enthalpy, convenient preparation and outstanding sustainability. Notably, the work provided a sustainable idea for the design of anti-leakage and shape-stable PEG-based PCMs.
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    Bio-based poly (glycerol-itaconic acid)/PEG/APP as form stable and flame-retardant phase change materials
    (Composites Communications, 2022) Yin, Guang-Zhong; Yang, Xiao-Mei; Hobson, Jose; Marta López, Alba; De-Yi, Wang
    With the improvement of people's living level, smart home and comfortable life put forward novel and highly scientific requirements for building materials and home environment. Environmental protection, renewability, processing convenience and use safety (non-toxic/fire safety) are all core indicators that need to be considered in an all-round way in the process of material design. In this work, we used a simple and efficient green process by blending ammonium polyphosphate (APP) and poly (glycerol-itaconic acid) loaded polyethylene glycol (PEG) to prepare fire safe phase change materials (PCMs). The flame retardancy, phase change performance and thermal response behavior (including form stability, thermal conductivity, cycle stability, and latent heat etc.) were systematically characterized. The results showed that limiting oxygen index (LOI) increased significantly with the increase of APP content. Typically, when the filling amount of APP reached 15 wt%, the LOI value increased from 21.6% to 28.7%, vertical testing reached UL-94 V0 rating and the pHRR decreased by 36.15%. The as-prepared PCMs show excellent form stability, and the enthalpy of phase change keeps higher than 70 J g−1, which is at the high level as that of same kinds of PCMs. Notably, due to its high preparation efficiency for PCM fabrication and the profiles of all bio-based supporting matrix, solvent-free pathway, mild curing temperature, and fire safety, it is expected to be effectively applied in building for the thermal regulation.
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    Fully bio-based Poly (Glycerol-Itaconic acid) as supporter for PEG based form stable phase change materials.
    (Composites Communications, 2021) Yin, Guang-Zhong; Díaz Palencia, José Luis; De-Yi, Wang
    A novel fully bio-based Poly (Glycerol-Itaconic acid) (PGI) was designed and highly efficiently synthesized by solvent-free polycondensation. The Poly (ethylene glycol) (PEG) was used as the phase change material (PCM) working substance and encapsulated by the sustainable PGI supporter. PEG chains were tightly encapsulated with the PGI supporting material mainly under hydrogen bonds due to the structural compatibility between PGI and PEG. The PCMs can achieve high form stability and high phase change enthalpies in the same kinds of PCMs. Furthermore, the phase change temperatures and enthalpies of the PCMs can be adjusted conveniently by regulating the PEG content and molecular weight. Notably, this process extremely facilitates the realization of efficient mass production due to the eco-friendly nature, high efficiency and low cost.
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    Polyrotaxane: New generation of sustainable, ultra-flexible, form-stable and smart phase change materials.
    (Energy Storage Materials, 2021) Yin, Guang-Zhong; Hobson, Jose; Duan, Yanyan; De-Yi, Wang
    The development of thermal energy storage materials is the most attractive strategy to harvest the solar energy and increase the energy utilization efficiency. Phase change materials (PCMs) have received much attention in this research field for several decades. Herein, we reported a new kind of PCM micro topological structure, design direction, and the ultra-flexible, form-stable and smart PCMs, polyrotaxane. The structure of polyrotaxane was fully confirmed by 1H nuclear magnetic resonance, attenuated total reflection-fourier transform infrared and X-ray diffraction. Then the tensile properties, thermal stability in the air, phase change energy storage and shape memory properties of the films were systematically analyzed. The results showed that all the mechanical performance, thermal stability in air and shape memory properties of polyrotaxanes were enhanced significantly compared to those of polyethylene oxide (PEO). The form stability at temperatures above the melting point of PEO significantly increased with the α-CD addition. Further with the high phase transition enthalpy and excellent cycle performance, the polyrotaxane films are therefore promising sustainable and advanced form-stable phase change materials for thermal energy storage. Notably, its ultra-high flexibility, remolding ability and excellent shape memory properties provide a convenient way for the intelligent heat treatment packaging of complex and flexible electronic devices. In addition, this is a totally novel insight for polyrotaxane application and new design method for form-stable PCMs.
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    Polyrotaxane based leakage-proof and injectable phase change materials with high melting enthalpy and adjustable transition temperature.
    (Chemical Engineering Journal, 2022) Yin, Guang-Zhong; López, Alba Marta; Yang, Xiao-Mei; Ao, Xiang; Hobson, Jose; De-Yi, Wang
    In this work, a series of advanced phase change materials (PCMs) were fabricated by using polyrotaxane (PLR) as supports for encapsulating poly (ethylene glycol) (PEG). Phase-change enthalpy is mainly regulated by the PEG contents, whereas phase change temperature is controlled by PEG molecular weight. All PCMs have good form stabilities due to the good compatibility between PLR and PEG, and supporting ability of PLR. Given that the PLR support itself has phase-transition properties, the resulting composites have high phase change enthalpies (116.1–162.2 J g -1) and very high enthalpy efficiency (>100%). It is a green and efficient preparation method because the whole preparation process did not involve organic solvents, and the material was prepared at room temperature. In addition, the obtained PCMs can be easily extruded and re-molded, which provides technical premise and convenience for the large-scale applications. As a typical application example, the PCMs showed its significant advantages in simulated solid-state disk model temperature regulation, which fully demonstrates the practical and superior application value of the PCMs in the field of thermal management for electronic devices.
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    Synergistic Effect of Cerium Oxide for Improving the Fire-Retardant, Mechanical and Ultraviolet-Blocking Properties of EVA/Magnesium Hydroxide Composites.
    (Materials, 2022) Hobson, Jose; Yin, Guang-Zhong; Yu, Xiaoli; Zhou, Xiaodong; Gonzalez Prolongo, Silvia; Ao, Xiang; De-Yi, Wang
    Rare earth oxide particles have received important attention in recent years, and due to the wide diversity of promising applications, the need for this kind of material is predicted to expand as the requirements to use the current resources become more demanding. In this work, cerium oxide (CeO2) was introduced into ethylene-vinyl acetate (EVA)/magnesium hydroxide (MDH) composites for enhancing the flame retardancy, mechanical properties and anti-ultraviolet aging performance. The target EVA/MDH/CeO2 composites were prepared by extrusion and injection molding, and the effects of the addition of the CeO2 were explored by thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), limiting oxygen index (LOI), UL-94, cone calorimetry test, and anti-ultraviolet aging test. Typically, the incorporation of the CeO2 allows a significant increase of the elongation at break and Young’s modulus compared with EVA/MDH by 52.25% and 6.85%, respectively. The pHRR remarkably decreased from 490.6 kW/m2 for EVA/MDH to 354.4 kW/m2 for EVA/MDH/CeO2 composite. It was found that the CeO2 presents excellent synergism with MDH in the composites for the anti-UV properties in terms of mechanical properties preservation. Notably, the combination of CeO2 with MDH is a novel and simple method to improve the filler–polymer interaction and dispersion, which resulted in the improvement of the mechanical properties, flame retardancy and the anti-ultraviolet aging performance of the composites.
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    Recent Progress on Multifunctional Thermally Conductive Epoxy Composite.
    (Polymers, 2023) Zhou, Mei-Hui; Yin, Guang-Zhong; González Prolongo, Silvia; De-Yi, Wang
    In last years, the requirements for materials and devices have increased exponentially. Greater competitiveness; cost and weight reduction for structural materials; greater power density for electronic devices; higher design versatility; materials customizing and tailoring; lower energy consumption during the manufacturing, transport, and use; among others, are some of the most common market demands. A higher operational efficiency together with long service life claimed. Particularly, high thermally conductive in epoxy resins is an important requirement for numerous applications, including energy and electrical and electronic industry. Over time, these materials have evolved from traditional single-function to multifunctional materials to satisfy the increasing demands of applications. Considering the complex application contexts, this review aims to provide insight into the present state of the art and future challenges of thermally conductive epoxy composites with various functionalities. Firstly, the basic theory of thermally conductive epoxy composites is summarized. Secondly, the review provides a comprehensive description of five types of multifunctional thermally conductive epoxy composites, including their fabrication methods and specific behavior. Furthermore, the key technical problems are proposed, and the major challenges to developing multifunctional thermally conductive epoxy composites are presented. Ultimately, the purpose of this review is to provide guidance and inspiration for the development of multifunctional thermally conductive epoxy composites to meet the increasing demands of the next generation of materials.
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    PLA aerogel as a universal support for the typical organic phase change energy storage materials.
    (Journal of Energy Storage, 2023) Yin, Guang-Zhong; Yang, Xiao-Mei; López, Alba Marta; Ao, Xiang; Wang, Mei-Ting; García Molleja, Javier; De-Yi, Wang
    We first prepared Polylactic acid (PLA) aerogels with high porosity based on a facile and efficient thermal induced phase separation technique. In view of the excellent internal nano structure of PLA aerogel, high porosity and suitable interfacial affinity, it was selected as a support material to encapsulate four common organic phase change materials (PCMs), thereby preparing anti-leakage, shape-stable and sustainable PCMs with ultra-high latent heat (178.9–224.9 J g−1). PLA aerogel encapsulated PCMs perform high enthalpy efficiency (>92 %), which may benefit from the highly internal compatible nanostructure of PLA. Thermally conductive fillers (Boron nitride and Graphene nanoplatelet) were introduced to improve thermal conductivity. An important factor of PLA aerogel as a universal encapsulation matrix is analyzed based on the solubility parameters and Flory-Huggins parameters. The application cases of smart container and thermal regulation in confined spaces further prove the practical application value in the thermal regulation and energy saving area.
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    Nanocarbon-Based Flame Retardant Polymer Nanocomposites.
    (Molecules, 2021) Yang, Yuan; Díaz Palencia, José Luis; Wang, Na; Jiang, Yan; De-Yi, Wang
    In recent years, nanocarbon materials have attracted the interest of researchers due to their excellent properties. Nanocarbon-based flame retardant polymer composites have enhanced thermal stability and mechanical properties compared with traditional flame retardant composites. In this article, the unique structural features of nanocarbon-based materials and their use in flame retardant polymeric materials are initially introduced. Afterwards, the flame retardant mechanism of nanocarbon materials is described. The main discussions include material components such as graphene, carbon nanotubes, fullerene (in preparing resins), elastomers, plastics, foams, fabrics, and film–matrix materials. Furthermore, the flame retardant properties of carbon nanomaterials and their modified products are summarized. Carbon nanomaterials not only play the role of a flame retardant in composites, but also play an important role in many aspects such as mechanical reinforcement. Finally, the opportunities and challenges for future development of carbon nanomaterials in flame-retardant polymeric materials are briefly discussed.