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In this study, reduced graphene oxide (rGO)/boron nitride (BN) anisotropic aerogels (CGAs) used as the heat conduction network were prepared by one-step heat flow method to improve the low thermal conductivity and low heat transfer efficiency of phase change materials. Composite phase change materials (CPCMs) were obtained after vacuum adsorption of paraffin. The structure and thermal properties of the samples were then characterized. The results showed that the anisotropic aerogel was successfully prepared and the corresponding CPCM axial thermal conductivity was 1.68 W/(m K) when the graphene oxide (GO)/BN used to prepare the CGA was 1:20, which was 504% higher than pure paraffin. After 50 cycles, the paraffin leakage rate was 3.1%, and the enthalpy loss rate was 2.7%. When simulating the actual temperature change, the paraffin phase change time could be advanced by approximately 1210 s, and the paraffin phase change efficiency could be improved by approximately 47%. CPCMs have high thermal conductivity, high heat transfer efficiency, and high thermal conduction network stability. They exhibit high heat transfer efficiency and can be used in the fields of thermal energy storage and solar energy conversion and so on.

In this paper, a novel composite is constructed as a non-enzymatic hydrogen peroxide (H 2 O 2 ) sensor by liquid-phase exfoliation method, which is composed of copper oxide, cuprous oxide and silver nanoparticles doped few-layer-graphene (Cu x O/Ag@FLG). Its surface morphology and composition were characterized by scanning electron microscopy (SEM) and X-ray photo spectroscopy (XPS), and its H 2 O 2 sensing performances include catalytic reduction and quantitative detection were studied with electrochemical methods. Our sensor had a high sensitivity of 174.5 μA mM −1  cm −2 (R 2  = 0.9978) in an extremely wide range of concentrations from 10 μM to 100 mM, a fast response (about 5 s) and a low limit of detection (S/N = 3) of 2.13 μM. The sensor exhibits outstanding selectivity in the presence of various biological interference, such as dopamine, ascorbic acid, uric acid, citric acid, etc. In addition, the constructed sensor continued 95% current responsiveness after 1 month of storage further points to its long-term stability. Last but not least, it has a good recovery rate (90.12–102.00%) in milk sold on the open market, indicating that it has broad application possibilities in the food industry and biological medicine.

In this study, feather keratin/polyvinyl alcohol/tris(hydroxymethyl)aminomethane (FK/PVA/Tris) bionanocomposite films containing graphene oxide (GO) (0.5, 1, 2, and 3 wt%) or graphene (0.5, 1, 2, and 3 wt%) were prepared using a solvent casting method. The scanning electron microscopy results indicated that the dispersion of GO throughout the film matrix was better than that of graphene. The successful formation of new hydrogen bonds between the film matrix and GO was confirmed through the use of Fourier-transform infrared spectroscopy. The tensile strength, elastic modulus, and initial degradation temperature of the films increased, whereas the total soluble mass, water vapor permeability, oxygen permeability, and light transmittance decreased following GO or graphene incorporation. In summary, nanoblending is an effective method to promote the application of FK/PVA/Tris-based blend films in the packaging field.

In this study, we investigated the directional heating of graphene oxide (GO) dispersion to generate a temperature gradient and form a simulated “ocean current” inside the dispersion so that GO sheets could be aligned in a directional manner and then reduced and self-assembled into anisotropic reduced graphene oxide (rGO) gel. After freeze-drying and varying degrees of vacuum microwave treatment, anisotropic chemically derived graphene aerogels (AGAs) were obtained. Through performance detection and the analysis of the results, it was verified that the AGAs with certain characteristics of “ocean current” were prepared in this experiment, and its axial direction has obvious directional arrangement. After being treated by vacuum microwave for a short time (1 min.), the axial thermal conductivity of the composite materials (AGA-adsorbed paraffin) was observed to be 1.074 W/mK, and the thermal conductivity enhancement efficiency was 995%; as compared with similar thermal conductivity enhancement composites that were found in previous studies, the proposed method in this paper has the advantages of simple processing, high efficiency, and energy conservation.

A novel superabsorbent polymer composite was synthesized by graft copolymerization of cottonseed protein and acrylic monomers in order to explore the new application of cottonseed protein in nonfood field. This composite was synthesized by solution based copolymerization, using partly neutralized acrylic acid, acrylamide and cottonseed protein as raw material, N,N‐methylene bisacrylamide as crosslinking agent, potassium persulphate and sodium sulfite as the initiators. The effects of the certain variables of the copolymerization on the water absorbency of the synthesized composite were measured. The chemical structure of the composite was characterized by means of Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetry analysis. The swelling properties of the composite were carried out under varying pH conditions. Further, the saline sensitivity, swelling kinetics and water retention ability of the composite was investigated. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

In this study, anisotropic graphene/graphene oxide (GO) aerogels (AGAs) were obtained by freeze-drying after direct participation of pristine graphene in the self-assembly of anisotropic gel by the heat flow method. After vacuum microwave treatment, the physical, chemical and structural characteristics of the AGAs were investigated. The results show that AGAs, in which the internal graphene sheets are parallel to the heat flow direction, are successfully prepared. After microwave treatment, the amount of oxygen and nitrogen reduces significantly and the sp2 domain increases. However, at the same time, many fragments and holes are generated in the graphene sheets. The effects of AGAs on the phase transition of paraffin is studied, and the results show that the melting enthalpy, solidification enthalpy and initial melting temperature of AGA/paraffin composites decreases as the GO content in the AGAs increases, whereas the melting range, solidifying range and subcooling degree increases. The highest axial thermal conductivity of the AGA/paraffin composite is 1.45 W/(mK), and the thermal conductivity enhancement efficiency is 884% (AGA content was 0.53 vol %). Compared with previously investigated, similar AGA/paraffin composites, the aerogels fabricated in this study have the obvious advantages of a simple fabrication process, a low cost and a high thermal conductivity enhancement efficiency. These aerogels possess the potential for application in phase-change energy storage (PES), thermal energy management and other fields.

The interpenetrating polymer network of fast temperature-responsive hydrogels based on soy protein and poly(N-isopropylacrylamide) were successfully prepared using the sodium bicarbonate (NaHCO3) solutions as the reaction medium. The structure and properties of the hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and thermal gravimetric analysis. The swelling and deswelling kinetics were also investigated in detail. The results have shown that the proposed hydrogels had high porous structure, good miscibility and thermal stability, and fast temperature responsivity. The presence of NaHCO3 had little effect on the volume phase transition temperature (VPTT) of the hydrogels, and the VPTTs were at about 32?C. Compared with the traditional hydrogels, the proposed hydrogels had much faster swelling and deswelling rate. The swelling mechanism of the hydrogels was the non-Fickian diffusion. This fast temperature-responsive hydrogels may have potential applications in the field of biomedical materials. nema

The development of plant adhesive with good bonding strength, water resistance and thermal stability remains challenging to replace formaldehyde-based adhesive resins that usually release toxic formaldehyde. Herein, an environmentally friendly bioadhesive derived from cottonseed meal waste and cellulose sawdust was successfully prepared, verified by FTIR and X-ray photoelectron spectroscopy detailed analysis. Pretreatment of cottonseed meal and sawdust at mild conditions was made to obtain cottonseed protein, purified and oxidized cellulose. Structure of these treated samples was characterized by particle size distribution, FTIR and wide angle X-ray diffraction. When adding 15% of the oxidized cellulose into cottonseed protein, the dry bonding strength of the resulting adhesive reached 2.4 MPa on average; and the highest wet bonding strength of 1.1 MPa was found when 10% dialdehyde starch was used. The improvements of bonding strength as well as thermal stability of the prepared oxidized cellulose/cottonseed protein adhesives are largely ascribed to the formation of strong chemical bonds and their mechanical interlocking with plywood substrates. Both protein-oxidized cellulose and protein-oxidized starch cross-linking networks are formed in the adhesive system, combining tightly the adhesive components. The biodegradable adhesive fabricated in work provides a new approach for the development of all-biomass derived adhesives with properties comparable to the state-of-the-art protein derived bioadhesives, thus holding great potential as an alternative to formaldehyde-based resins in wood board and indoor panel bonding industries. Graphical abstract

Feathers, which contain >90% keratin, are valuable natural protein resources. The aim of this study is to prepare antimicrobial feather keratin (FK)-based nanofibers by incorporating silver nanoparticles (AgNPs). A series of AgNPs-embedded feather keratin/poly(vinyl alcohol)/poly(ethylene oxide) (FK/PVA/PEO) composite nanofibers with varying amounts of AgNPs content were fabricated by electrospinning. Their morphology, crystallinity, thermal stability, tensile property, and antibacterial activity were systematically investigated. The average diameters of composite nanofibers gradually decreased with increases in the amount of AgNPs. The crystallinity, thermal stability, and antibacterial activity of FK/PVA/PEO nanofibers were enhanced by embedding AgNPs. When embedded with 1.2% AgNPs, both the tensile strength and elongation-at-break reached the highest level. This work has the potential to expand the application of FK-based nanofibers in the biomaterial field.

The development of edible films based on the natural biopolymer feather keratin (FK) from poultry feathers is of great interest to food packaging. Edible dialdehyde carboxymethyl cellulose (DCMC) crosslinked FK films plasticized with glycerol were prepared by a casting method. The effect of DCMC crosslinking on the microstructure, light transmission, aggregate structure, tensile properties, water resistance and water vapor barrier were investigated. The results indicated the formation of both covalent and hydrogen bonding between FK and DCMC to form amorphous FK/DCMC films with good UV-barrier properties and transmittance. However, with increasing DCMC content, a decrease in tensile strength of the FK films indicated that plasticization, induced by hydrophilic properties of the DCMC, partly offset the crosslinking effect. Reduction in the moisture content, solubility and water vapor permeability indicated that DCMC crosslinking slightly reduced the moisture sensitivity of the FK films. Thus, DCMC crosslinking increased the potential viability of the FK films for food packaging applications, offering a value-added product.