3D copper nanowires-thermally annealed graphene aerogel (CuNWs-TAGA) framework is firstly prepared by freeze-drying followed by thermal annealing from CuNWs, graphene oxide (GO) and L-ascorbic acid. Epoxy resin is then poured back into the above 3D CuNWs-TAGA framework to fabricate the CuNWs-TAGA/epoxy nanocomposites. CuNWs with average diameter of about 120 nm and length of approximate 10 μm are successfully prepared. When the mass fraction of CuNWs-TAGA is 7.2 wt% (6.0–1.2 wt% CuNWs-TAGA), the thermal conductivity coefficient (λ) value of the CuNWs-TAGA/epoxy nanocomposites reaches the maximum of 0.51 W/mK. Meantime, the CuNWs-TAGA/epoxy nanocomposites exhibit the maximum electromagnetic interference shielding effectiveness (EMI SE) value of 47 dB and electrical conductivity (σ) of 120.8 S/m, ascribed to perfect 3D CuNWs-TAGA conductive network structures. Meanwhile, the corresponding elasticity modulus, hardness, glass transition temperature (Tg) and heat-resistance index (THRI) of the CuNWs-TAGA/epoxy nanocomposites increase to 4.69 GPa, 0.33 GPa, 126.3 °C and 181.7 °C, respectively.

Synchronously improved electromagnetic interference shielding and thermal conductivity for epoxy nanocomposites by constructing 3D copper nanowires/thermally annealed graphene aerogel framework

Over the past few years, nanocellulose (NC), cellulose in the form of nanostructures, has been proved to be one of the most prominent green materials of modern times. NC materials have gained growing interests owing to their attractive and excellent characteristics such as abundance, high aspect ratio, better mechanical properties, renewability, and biocompatibility. The abundant hydroxyl functional groups allow a wide range of functionalizations via chemical reactions, leading to developing various materials with tunable features. In this review, recent advances in the preparation, modification, and emerging application of nanocellulose, especially cellulose nanocrystals (CNCs), are described and discussed based on the analysis of the latest investigations (particularly for the reports of the past 3 years). We start with a concise background of cellulose, its structural organization as well as the nomenclature of cellulose nanomaterials for beginners in this field. Then, different experimental procedures for the production of nanocelluloses, their properties, and functionalization approaches were elaborated. Furthermore, a number of recent and emerging uses of nanocellulose in nanocomposites, Pickering emulsifiers, wood adhesives, wastewater treatment, as well as in new evolving biomedical applications are presented. Finally, the challenges and opportunities of NC-based emerging materials are discussed.

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Nanocellulose: From Fundamentals to Advanced Applications

Electrospun nanofiber membranes for wastewater treatment applications

A review of melting and freezing processes of PCM/nano-PCM and their application in energy storage

Melamine foam/reduced graphene oxide supported form-stable phase change materials with simultaneous shape memory property and light-to-thermal energy storage capability

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.

Cellulose-graphene nanosheet composite aerogel, preparation method thereof, phase change material as well as preparation method and application of phase change material

Achieving ultrahigh synergistic effect in enhancing conductive properties of polymer composites through constructing the hybrid network of ‘rigid’ submicron vapor grown carbon fibers and ‘reelable’ carbon nanotubes

The rigidity of battery thermal management systems (BTMS) and harsh environments are the obstacles to the development of fast charging/discharging of lithium-ion batteries. Herein, a straightforward path is provided to solve the above dilemma by synthesizing styrene-b-(ethylene-co-butylene)-b-styrene/paraffin wax/helical carbon nanotubes (SEBS/PW/HCNTs). 2D wide-angle X-ray diffraction demonstrated that the PW solid skeleton of SEBS/PW composites oriented along the stretching direction under the tensile stress resisted the elastic potential energy of SEBS to achieve room-temperature shape fixation. Furthermore, HCNTs as a three-dimensional and photo-thermal conversion filler were incorporated into SEBS/PW to impart the composites with rapid light-actuated shape memory and light-thermal conversion/storage capacities. Finally, a BTMS with high phase change efficiency (95.3%), reversible plasticity shape memory (RPSM), photo-thermal conversion and wide-temperature thermal management range from −60 to 50 °C was manufactured by combining the heating and cooling subsystems, which exhibited vast prospects in battery thermal management fields. 

Helical carbon nanotubes filled phase change composites with reversible plasticity shape memory and photo-thermal conversion functions towards wide-temperature-range battery thermal management

The invention discloses a composite paraffin phase change material and a preparation method thereof. The method for preparing the composite paraffin phase change material comprises the following steps: mixing graphite oxide dispersion and graphite nanosheets, and performing ultrasonic dispersion to form dispersion, wherein a mass ratio of the graphite oxide to the graphite nanosheets is 1 to 1-20;mixing a reducing agent and the dispersion and adding into melamine foam, wherein a mass ratio of the reducing agent to the graphite oxide is 1-5 to 1; extruding the melamine foam, and enabling the melamine foam to absorb the dispersion; reacting the melamine foam absorbed with the dispersion under the condition of 70-200 DEG C so as to obtain hydrogel; dialyzing the hydrogel, performing freeze-drying to obtain aerogel, and carbonizing the aerogel under inert gas protection under the condition of 500-3000 DEG C so as to obtain the carbide; dipping the carbide in liquid paraffin at the temperature of 60-100 DEG C under the vacuum condition. The method is simple, and the composite paraffin phase change material with excellent heat-conducting property and high energy density can be prepared.

Composite paraffin phase change material and preparation method thereof

With the rapid development of electrical equipment and integrated circuits, packaging materials with high heat dissipation capability are in great demand. Reducing the interfacial thermal resistance is still a great challenge in polymeric composites. Herein, surface-induced polyamide acid (PAA) polymerization on boron nitride nanosheets (BNNSs) was firstly achieved, and then the BNNS@PAA was introduced into the polymerization system of polyimide (PI). The dependence of microstructures and performances of the composites on imidization degree of BNNS@PAA was systematically investigated. The results show that there is an appropriate imidization temperature (120 °C), at which the composite with only 10 wt% BNNS@PAA exhibits high thermal conductivity (2.11 W/m·K), excellent mechanical properties (with tensile strength of 97.2 MPa and elongation at break of 19.8%), and good dielectric properties (with a discharged energy density of 3.67 J/cm 3 and a charge-discharge efficiency of 87.4% at the field of 300 MV/m). 

Xiao-dong Qi

Papers

Cellulose-graphene nanosheet composite aerogel, preparation method thereof, phase change material as well as preparation method and application of phase change material

Achieving ultrahigh synergistic effect in enhancing conductive properties of polymer composites through constructing the hybrid network of ‘rigid’ submicron vapor grown carbon fibers and ‘reelable’ carbon nanotubes

Helical carbon nanotubes filled phase change composites with reversible plasticity shape memory and photo-thermal conversion functions towards wide-temperature-range battery thermal management

Composite paraffin phase change material and preparation method thereof

High performances of polyimide/boron nitride nanosheets composites via integrative interfacial decoration strategy