Showing papers by "Xiao-dong Qi published in 2019"
TL;DR: In this article, a composite phase change material (PCM) was fabricated based on commercial melamine foam (MF) incorporated by the graphene oxide (GO) and graphene nanoplatelets (GNPs).
166 citations
TL;DR: It is expected that the novel electrospun composite membrane with dual-scaled porous structure and nanoraised structure on each fiber can be used in oily wastewater treatment under various conditions through one-off adsorption or continuous oil/water separation, especially under low environmental temperature condition.
Abstract: Developing highly efficient and multifunctional membranes toward oil adsorption and oil/water separation is of significance in oily wastewater treatment. Herein, a novel electrospun composite membrane with dual-scaled porous structure and nanoraised structure on each fiber was fabricated through electrospinning using biodegradable polylactide (PLA) and magnetic γ-Fe2O3 nanoparticles. The PLA/γ-Fe2O3 composite membranes show high porosity (>90%), superhydrophobic and superlipophilic performances with CH2I2 contact angle of 0°, good water adhesion ability like water droplets on a petal surface, excellent anti-icing performance, and good mechanical properties with a tensile strength of 1.31 MPa and a tensile modulus of 11.65 MPa. The superlipophilicity and dual-scaled porous structure endow the composite membranes with ultrahigh oil adsorption capacity up to 268.6 g/g toward motor oil. Furthermore, the composite membranes also show high oil permeation flux up to 2925 L/m2 h under the force of gravity. Even for oil/water emulsion, the composite membranes have high separation efficiency. We expect that the PLA/γ-Fe2O3 composite membranes can be used in oily wastewater treatment under various conditions through one-off adsorption or continuous oil/water separation, especially under low environmental temperature condition.
102 citations
TL;DR: With high thermal energy storage capability, excellent shape memory properties, shape designability, and stable cycling reliability, this multifunctional MF/PW PCM shows a promising application in thermal energy management systems.
Abstract: Paraffin wax (PW) is widely used as a phase change material (PCM) in the thermal energy storage field, whereas the leakage and strong rigidity of PW have hindered its practical applications. In this work, binary melamine foam (MF)/PW blends with simultaneous thermal energy storage and shape memory properties were prepared through vacuum impregnation. Herein, PW performs as a latent heat storage material and as a switching phase for shape fixation and MF serves as a supporting material to prevent the leakage and as a permanent phase for shape recovery. Due to the light weight and super-elasticity of MF, the MF/PW PCMs possess not only good encapsulation ability and a high latent heat, but also excellent shape-fixing and recovery properties (shape-fixing and recovery ratios are about 100%). Besides, the MF/PW PCMs can be fabricated into arbitrary shapes using MF as a template, and they exhibit excellent shape memory cyclic performance and thermal reliability. A temperature-sensitive and temperature-controlled deployable panel is further established, which can be installed in the electronic device and used for temperature protection. With high thermal energy storage capability, excellent shape memory properties, shape designability, and stable cycling reliability, this multifunctional MF/PW PCM shows a promising application in thermal energy management systems.
101 citations
TL;DR: In this article, form-stable phase change materials (PCMs) are widely used for thermal management, however, the strong rigidity and the weak photoabsorption ability have hindered their practical applications.
Abstract: Form-stable phase change materials (PCMs) are widely used for thermal management. However, the strong rigidity and the weak photoabsorption ability have hindered their practical applications. Herei...
95 citations
TL;DR: In this article, a facile and novel method to prepare the composite phase change materials (PCMs) was proposed, which exhibited relatively high thermal conductivity (1.03 W/mK), high latent heat (182.6 W/g), excellent encapsulation ability and mechanical stability.
92 citations
TL;DR: A shape-adaptable FSPCM with the coinstantaneous light/electro-driven shape memory property and light/Electro-to-thermal energy storage performance and a light-sensitive, shape- Adaptable and thermal-insulating container is explored.
Abstract: Strong rigidity, low thermal conductivity, and short of multi-driven capabilities of form-stable phase change materials (FSPCMs) have limited their practical utilization. Herein, we report a shape-adaptable FSPCM with the coinstantaneous light/electro-driven shape memory properties and light/electro-to-thermal energy storage performance. The FSPCM is fabricated by incorporating the poly(ethylene glycol) (PEG) into the cellulose nanofiber/graphene nanoplatelet (GNP) hybrid-coated melamine foam (CG@MF). The CG@MF/PEG FSPCMs show a good encapsulation effect, enhanced thermal conductivity, and large melting enthalpy (178.9 J g-1). Due to the high elasticity of MF and the excellent photothermal conversion and electrical conductivity of the GNP network, the CG@MF/PEG FSPCMs exhibit a remarkable light/electro-driven shape memory effect by activating the phase change process of PEG. Meanwhile, the CG@MF/PEG FSPCMs can effectively convert light or electric energy into heat energy and reposit the converted energy during the phase change process. Furthermore, the CG@MF/PEG FSPCMs possess excellent multiresponsive self-adhesion properties. A light-sensitive, shape-adaptable, and thermal-insulating container is further explored. This study provides routes toward the development of multiresponsive shape-adaptable FSPCMs for energy storage applications.
90 citations
TL;DR: In this article, an insulated polyimide interlayer with nanoscale thickness was coated on the surface of barium titanate (BaTiO3, BT) through the in-situ polymerization and subsequent thermal imidization treatment.
73 citations
TL;DR: Results clearly showed that the composite PCMs had excellent light-to-heat energy transition ability and could be used as a thermal management component to suppress the overheating of devices during the operation process, or to supply energy for thermoelectric devices under emergency conditions to ensure a continuous power supply sustained for a certain time until the safeguard procedures are adopted.
Abstract: Phase change materials (PCMs) exhibit wide application prospects in many fields related to energy utilization and management and attract increasing interest. In this work, through the graphene oxide (GO)-assisted dispersion technology, GO/boron nitride (BN) nanosheets were incorporated into melamine foam and successfully deposited on the surface of the foam framework after hydrothermal reaction. Through the following freeze-drying and carbonization treatment, the composite MF/rGO/BN aerogels were obtained with integrated hybrid rGO/BN frameworks. The composite PCMs were prepared through encapsulating polyethylene glycol (PEG) within the hybrid aerogels. The encapsulation stability and thermal properties of the composite PCMs were systematically investigated. The composite PCM sample containing the highest content of rGO/BN exhibited excellent encapsulation stability, high thermal conductivity (up to 0.79 W m-1 K-1), high phase change enthalpy (160.7 J g-1) with the retention of 90.8% of the pure PEG, and excellent chemical and thermal stability. Further results clearly showed that the composite PCMs had excellent light-to-heat energy transition ability and could be used as a thermal management component to suppress the overheating of devices during the operation process, or to supply energy for thermoelectric devices under emergency conditions to ensure a continuous power supply sustained for a certain time until the safeguard procedures are adopted.
72 citations
TL;DR: In this article, the flexible and light-responsive phase change materials (PCM composites) consisting of paraffin and olefin block copolymer (OBC) filled with carbon nanotubes (CNTs) were prepared.
67 citations
TL;DR: In this article, two kinds of poly(vinylidene fluoride) (PVDF)-based composites, including PVDF/BaTiO3@PPy and PVDF-Ba TiO3-PPy-GO, were fabricated.
45 citations
TL;DR: In this article, ZnO nanoparticles and graphene oxide (GO) nanosheets are self-assembled to form the hybrid ZnOs@GO nanoparticles through the simple solution compounding processing with the aid of ultrasonic treatment.
Abstract: Zinc oxide (ZnO) nanoparticles and graphene oxide (GO) nanosheets are self-assembled to form the hybrid ZnO@GO nanoparticles through the simple solution compounding processing with the aid of ultrasonic treatment. There is a good interaction between ZnO and GO, which promotes the deposition of ZnO nanoparticles on the surface of GO nanosheets and the exfoliation of GO nanosheets. Microstructure and morphology characterizations of the poly(vinylidene fluoride) (PVDF)-based composites show that the PVDF/ZnO@GO composites exhibit largely improved dispersion of fillers compared with the PVDF/GO composites. At high filler content, ZnO@GO nanoparticles also induce the change of α-form to β-form PVDF. The hybrid ZnO@GO nanoparticles endow the composites with high relative permittivity, low dielectric loss and high breakdown strength. Furthermore, the composite samples also show good flexibility. This work confirms that incorporating the hybrid nanoparticles that are composed of semi-conductive fillers is an efficient way to prepare the dielectric composites with promising properties.
TL;DR: This SMP composites with enhanced light responsivity and mechanical properties are believed to have great potential in many fields such as light energy harvesting and remote-controlled actuators.
TL;DR: In this article, three kinds of boron nitride (BN) particles with different sizes were combined with carbon nanotubes (CNTs) to prepare the polyvinylidene fluoride (PVDF) composites.
TL;DR: In this paper, a ternary polystyrene (PS) composites containing graphene nanoplatelets (GNPs) and carbon nanofibers (CNFs) were prepared through solution compounding processing.
Abstract: Polystyrene (PS) composites containing graphene nanoplatelets (GNPs) and carbon nanofibers (CNFs) were prepared through solution compounding processing. The results showed that more compact network structure was formed in the ternary PS/GNP/CNF composites, and the composites exhibited apparently enhanced heat resistance compared with the pure PS sample. Conductive properties measurements showed that largely reduced percolation threshold was achieved for the ternary PS/GNP/CNF composites. Furthermore, the PS/GNP/CNF composites had good thermal conductivity. At GNP content of 2 vol% and CNF content of 5.5 vol%, the thermal conductivity was enhanced to 1.12 W/mK, which was 522% higher than that of the pure PS sample. The potential application of the PS composites as the material of heat radiator was also evaluated, and the results showed that the composites exhibited excellent heat transferring ability. This work indicates that the PS/GNP/CNF composites may be used in the field relating to high temperature and load conditions.
TL;DR: In this paper, a few carbon nanotubes (CNTs) and 1,2,3,4-bis(3, 4-dimethylbenzylidene sorbitol) were incorporated into polypropylene/ethylene-propylene-diene terpolymer (PP/EPDM) (85/15, wt/wt) blends.
TL;DR: PPy@BTOH composite particles with a ‘mulberry-like’ structure are fabricated to prepare dielectric composites with excellent comprehensive dielectrics properties.
Abstract: Polymer dielectric composites have widespread applications in many fields ranging from energy storage, microelectronic devices, and sensors to power driven systems, etc. and attract much attention of researchers. However, it is still challenging to prepare advanced polymer dielectric composites with a high dielectric constant (e′), low dielectric loss (tan δ) and simultaneously high breakdown strength (Ebd). In this work, conductive polypyrrole (PPy) nanoparticles were in situ synthesized in a reaction system containing the common barium titanate (BaTiO3, BT) or hydroxylated BaTiO3 (BTOH) particles, and then the PPy@BT and PPy@BTOH composite particles were incorporated into poly(vinylidene fluoride) (PVDF) to prepare the composites. The morphologies and microstructures of the PPy@BT and PPy@BTOH composite particles and the corresponding PVDF composites were comparatively investigated. The results showed that the PPy@BTOH composite particles had a ‘mulberry’-like morphology with a rough surface and the self-assembled structure could be maintained in the PVDF composites, which was apparently different from the PVDF/PPy@BT composites, in which most of the PPy nanoparticles dissociatively dispersed in the PVDF matrix. Electrical conductivity measurements showed that at high particle content (≥20 wt%), the PPy@BTOH composite particles endowed the composites with lower electrical conductivity compared with the PPy@BT composite particles. Dielectric property measurements showed that the ‘mulberry’-like PPy@BTOH composite particles endowed the PVDF composites with extremely high e′, ultralow tan δ and high Ebd compared with the PVDF/PPy@BT composites with dissociatively dispersed PPy nanoparticles and BaTiO3 particles. The polarization and loss mechanisms of the composites were then proposed based on the morphologies and the microstructures of the composites. This work provides an alternative way to fabricate functional dielectric particles through trace functional groups inducing in situ polymerization of conductive polymers, and these particles can be used to fabricate advanced dielectric composites.
TL;DR: In this paper, the grafting ratio of functional groups on f-CNFs was about 13.09% and after being grafted by polyethylene glycol (PEG), the grafted ratio was further enhanced up to 50.95% by using PEG-grafted CNFs.
TL;DR: In this article, carbon nanofibers (CNFs) and elastomer (styrene-ethylene/butylene-styrene, SEBS) were simultaneously incorporated into polystyrene (PS) through melt-compounding method.
Patent•
26 Mar 2019
TL;DR: The cellulose-graphene nanosheet composite phase change material can be produced into heating elements and has many advantages that the electric control and over-distance light control can be realized, the secondary machining is easy, the energy is saved, the contenttemperature time is long after a control circuit is cut off, and the like as discussed by the authors.
Abstract: The invention discloses cellulose-graphene nanosheet composite aerogel, a preparation method thereof, a phase change material as well as a preparation method and application of the phase change material, relating to the technical field of heating materials. According to the cellulose-graphene nanosheet composite aerogel and the preparation method, hydrogel is formed by cellulose and graphene, andthe composite aerogel is a brick net-similar structure with high orientation armament from top to bottom and is formed by the mutual stacking of cellulose and graphene nanosheets. According to the cellulose-graphene nanosheet composite phase change material and the preparation method, the cellulose-graphene nanosheet composite phase change material is prepared by the steps of filling the cellulose-graphene nanosheet composite aerogel with a fused filling material, cooling, and drying. The cellulose-graphene nanosheet composite phase change material can be produced into heating elements and hasmany advantages that the electric control and over-distance light control can be realized, the secondary machining is easy, the energy is saved, the content-temperature time is long after a control circuit is cut off, and the like.
Patent•
03 May 2019
TL;DR: In this paper, a multifunctional flexible phase change material, which comprises a light absorption medium, a phase change energy storage substance and an elastic substrate with a porous structure, is presented.
Abstract: The invention relates to the field of materials, and particularly relates to a multifunctional flexible phase-change material, a preparation method thereof and a building material. The multifunctionalflexible phase change material comprises a light absorption medium, a phase change energy storage substance and an elastic substrate with a porous structure, wherein the light absorption medium is supported on the elastic substrate, and the phase-change energy storage substance is distributed on the elastic substrate. According to the multi-functional flexible phase change material, phase changeenergy storage, shape memory and photo-thermal conversion functions are integrated, flexibility is achieved, and the multifunctional flexible phase change material is convenient to install and can beused circularly.
Patent•
21 May 2019
TL;DR: In this article, a composite material with both high toughness and high thermal conductivity is prepared from a fiber made of a fiber-forming polymer, carbon nanofibers and an ethylene copolymer.
Abstract: The invention relates to the field of materials, in particular to a composite material with both high toughness and high thermal conductivity as well as a preparation method and application thereof and an electronic packaging material. The composite material with both high toughness and high thermal conductivity is prepared from a fiber made of a fiber-forming polymer, carbon nanofibers and an ethylene copolymer, wherein the mass ratio of the fiber made of the fiber-forming polymer to the ethylene copolymer is (1-9):1; the mass of the carbon nanofibers accounts for 5 to 30 percent of the totalmass of the fiber made of the fiber-forming polymer and the ethylene copolymer. The composite material not only has good thermal conductivity, but also has good toughness.
Patent•
27 Sep 2019
TL;DR: In this paper, an organic photo-thermoelectric composite material, a preparation method and application thereof, a phototherm-means battery and an optical delay control system, and relates to the technical field of battery materials.
Abstract: The invention discloses an organic photo-thermoelectric composite material, a preparation method and application thereof, a photo-thermoelectric battery and an optical delay control system, and relates to the technical field of battery materials. The organic photo-thermoelectric composite material comprises a carbon nano tube and an organic polymer loaded on the carbon nano tube, wherein the organic polymer is doped with a dopant. The preparation method of the organic photo-thermoelectric composite material comprises the following steps: mixing the carbon nano tube, the dopant solution and a polymerization monomer to form a reaction mixed solution; and mixing the reaction mixed solution with an initiator, and performing polymerizing. The composite material has good photo-thermal and thermoelectric conversion performances, and compared with a traditional photo-thermal-thermoelectric conversion system, the photo-thermal-thermoelectric conversion capability and efficiency are greatly improved. The photo-thermoelectric battery is prepared from the composite material, and the conversion of photo-thermoelectricity can be more efficiently realized. A control system is formed by utilizing the photo-thermoelectric battery, the delay control is realized by controlling illumination, and the control system has the characteristics of short history list, stable operation, high sensitivity and the like.
Patent•
18 Jan 2019
TL;DR: In this paper, a cellulose-based porous aerogel with photocatalysis degradation activity and a preparation method for cellulose powder by a lithium bromide water solution under the temperature conditions of 110 to 140 DEG C was provided.
Abstract: The invention provides cellulose-based porous aerogel with photocatalysis degradation activity and a preparation method thereof, and relates to the technical field of aerogel The preparation method of the cellulose-based porous aerogel comprises the following steps of dissolving microcrystalline cellulose powder by a lithium bromide water solution under the temperature conditions of 110 to 140 DEG C; after the dissolution, mixing the materials mixture with graphene oxide and Cu2O to obtain a mixed solution; cooling the mixed solution to obtain an aquogel precursor; displacing lithium bromidein the aquogel precursor by usingwith a water solvent; after freezing drying, obtaining the cellulose-based porous aerogel The preparation method is simple; the prepared cellulose-based porous aerogel can realize the synchronous proceeding of adsorption and photocatalysis; the difficult direct decomposition ofproblem that organic matters are difficult to be directly decomposed is solved; the dyepost treatment work procedures are simplified
Patent•
01 Oct 2019
TL;DR: In this article, a thermoelectric material performance parameter testing device, system and method for bearing and testing of thermoceramic materials is presented. But, the performance parameters of the thermocorlectric materials to be tested can be acquired by arranging the first sample table and the second sample table on thenon-sharp planes.
Abstract: The embodiment of the invention provides a thermoelectric material performance parameter testing device, system and method. The thermoelectric material performance parameter testing device comprises afirst sample table, a second sample table and a containing structure, wherein one surface of the first sample stage and the second sample stage which is used for bearing the thermoelectric material to be tested is a non-sharp platform; the first sample table and the second sample table are oppositely arranged in an accommodating structure; and the first sample table and the second sample table are used for bearing and heating the thermoelectric material to be tested and acquiring performance parameters of the thermoelectric material to be tested. According to the thermoelectric material performance parameter testing device, system and method, the thermoelectric material to be tested can be borne and tested by arranging the first sample table and the second sample table which comprise thenon-sharp planes, so that the thermoelectric material to be tested is not damaged in the performance parameter testing process.
Patent•
15 Feb 2019
TL;DR: In this paper, a preparation method of a hydroxylated barium titanate and polypyrrole hybrid material, hybrid filler, a polymer composite material and an application of the composite material is described.
Abstract: The invention relates to the field of materials, in particular to a preparation method of a hydroxylated barium titanate and PPy (polypyrrole) hybrid material, hybrid filler, a polymer composite material and an application of the polymer composite material. The h-MBT@PPy hybrid filler is prepared from MBT particles by hydroxylation treatment and introduced into a PVDF (polyvinylidene fluoride) substrate, and the PVDF/h-MBT@PPy composite material is prepared. By means of the hydroxylation treatment process, content of hydroxyl on the surfaces of the MBT particles is increased, and a better assembling form is obtained. The contact area between the hybrid filler and the substrate is larger, so that dielectric property of the composite material is improved; the h-MBT particles are dispersed quite uniformly, accordingly, dielectric constant of the composite material is increased, and dielectric loss also keeps in a range equivalent to that of pure PVDF.