Hui Wang

Bio: Hui Wang is an academic researcher from Hefei Institutes of Physical Science. The author has contributed to research in topics: Electromagnetic shielding & Carbon nanotube. The author has an hindex of 3, co-authored 5 publications receiving 170 citations. Previous affiliations of Hui Wang include University of Science and Technology of China.

Segregated poly(vinylidene fluoride)/MWCNTs composites for high-performance electromagnetic interference shielding

Abstract: Conductive polymer composites (CPCs) that contain a segregated structure have attracted significant attentions because of their promising for fulfilling low filler contents with high electromagnetic interference (EMI) properties. In the present study, segregated poly(vinylidene fluoride) (PVDF)/multi-walled carbon nanotubes (MWCNTs) composites were successfully prepared by mechanical mixing and hot compaction. The PVDF/MWCNTs samples with 7 wt% filler content possess high electrical conductivities and high EMI shielding effectiveness (SE), reaching 0.06 S cm −1 and 30.89 dB (in the X-band frequency region), much higher than lots of reported results for CNT-based composites. And the EMI SE greatly increased across the frequency range as the sample thickness was improved from 0.6 to 3.0 mm. The EMI shielding mechanisms were also investigated and the results demonstrated absorption dominating shielding mechanism in this segregated material. This effective preparation method is simple, low-cost, and environmentally-friendly and has potential industrial applications in the future.

Synergistic effect of selectively distributed AlN/MWCNT hybrid fillers on the morphological, mechanical and thermal properties of polycarbonate/maleated poly[styrene-b-(ethylene-co-butylene)- b-styrene] triblock copolymer (SEBS-g-MA) composites

Abstract: A quaternary nanocomposite polycarbonate (PC)- multi-walled carbon nanotubes (MWCNT)/SEBS-g-MA (SM)-AlN is prepared by controlling the selective distribution of nano-fillers via melt-blending. Through a two-step mixing method, surface modified AlN is selectively dispersed in the island-like SM phase; meanwhile, MWCNT acting as bridges are mainly located in the continuous phase of PC. This 'island-bridge' morphology is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The selective localization results agree well with the theoretical predictions. Dynamic mechanical analysis (DMA) indicates that the addition of hybrid fillers improved the storage modulus selectively. Thermogravimetric analysis (TGA) shows that the thermal stability of the PC/SM blends increased significantly; the degradation kinetic has also been changed due to the synergistic effects of the fillers. This novel 'island-bridge' network contributes a higher thermal conductivity at low filler content as the effective thermal conductivity reached 0.72 W m−1 K−1, which is three times higher than that of 70PC/30SM. The experimental observations coincide well with the optimizing model results.

Light, conducting and shielding composite material and preparation method thereof

Abstract: The invention discloses a light, conducting and shielding composite material and a preparation method thereof The light, conducting and shielding composite material is composed of fluoroplastic, carbon nano tubes and hollow glass beads in a weight ratio of (20-60):(05-20):(05-40), wherein the fluoroplastic is foamed, and the carbon nano tubes are arranged in the fluoroplastic and are of a network structure The preparation method of the light, conducting and shielding composite material comprises the following steps: firstly uniformly mixing the fluoroplastic, an etching phase, the carbon nano tubes and the hollow glass beads, so as to obtain a mixture; then mixing the mixture in a torque rheometer, so as to obtain a mixed material; and then carrying out hot pressing on the mixed material on a plate vulcanization machine, so as to obtain a composite board, then soaking the composite board in a solvent for removing the etching phase, and drying, so as to obtain the target product, namely the light, conducting and shielding composite material The light, conducting and shielding composite material has the advantages of light weight, reliable electromagnetic shielding performance, good mechanical properties, simple technology, no pollution, low cost and applicability in large-scale industrial production, and can be easily and widely applied to electronic equipment and intensive systems in the fields of spaceflight, aviation, automobiles and the like

Lightweight conductive graphene/thermoplastic polyurethane foams with ultrahigh compressibility for piezoresistive sensing

Abstract: Lightweight conductive porous graphene/thermoplastic polyurethane (TPU) foams with ultrahigh compressibility were successfully fabricated by using the thermal induced phase separation (TISP) technique. The density and porosity of the foams were calculated to be about 0.11 g cm−3 and 90% owing to the porous structure. Compared with pure TPU foams, the addition of graphene could effectively increase the thickness of the cell wall and hinder the formation of small holes, leading to a robust porous structure with excellent compression property. Meanwhile, the cell walls with small holes and a dendritic structure were observed due to the flexibility of graphene, endowing the foam with special positive piezoresistive behaviors and peculiar response patterns with a deflection point during the cyclic compression. This could effectively enhance the identifiability of external compression strain when used as piezoresistive sensors. In addition, larger compression sensitivity was achieved at a higher compression rate. Due to high porosity and good elasticity of TPU, the conductive foams demonstrated good compressibility and stable piezoresistive sensing signals at a strain of up to 90%. During the cyclic piezoresistive sensing test under different compression strains, the conductive foam exhibited good recoverability and reproducibility after the stabilization of cyclic loading. All these suggest that the fabricated conductive foam possesses great potential to be used as lightweight, flexible, highly sensitive, and stable piezoresistive sensors.

Electromagnetic Interference Shielding Polymers and Nanocomposites - A Review

Abstract: Intrinsically conducting polymers (ICP) and conductive fillers incorporated conductive polymer-based composites (CPC) greatly facilitate the research in electromagnetic interference (EMI) s...

Ultralight Graphene Foam/Conductive Polymer Composites for Exceptional Electromagnetic Interference Shielding

Abstract: Ultralight, high-performance electromagnetic interference (EMI) shielding graphene foam (GF)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composites are developed by drop coating of PEDOT:PSS on cellular-structured, freestanding GFs. To enhance the wettability and the interfacial bonds with PEDOT:PSS, GFs are functionalized with 4-dodecylbenzenesulfonic acid. The GF/PEDOT:PSS composites possess an ultralow density of 18.2 × 10–3 g/cm3 and a high porosity of 98.8%, as well as an enhanced electrical conductivity by almost 4 folds from 11.8 to 43.2 S/cm after the incorporation of the conductive PEDOT:PSS. Benefiting from the excellent electrical conductivity, ultralight porous structure, and effective charge delocalization, the composites deliver remarkable EMI shielding performance with a shielding effectiveness (SE) of 91.9 dB and a specific SE (SSE) of 3124 dB·cm3/g, both of which are the highest among those reported in the literature for carbon-based polymer composites. The excelle...

Porous Co-C Core-Shell Nanocomposites Derived from Co-MOF-74 with Enhanced Electromagnetic Wave Absorption Performance.

Abstract: The combination of carbon materials and ferrite materials has recently attracted increased interest in microwave absorption applications. Herein, a novel composite with cobalt cores encapsulated in a porous carbon shell was synthesized via a facile sintering process with a cobaltic metal–organic framework (Co-MOF-74) as the precursor. Because of the magnetic loss caused by the Co cores and dielectric loss caused by the carbon shell with a unique porous structure, together with the interfacial polarization between two components, the ferromagnetic composite exhibited enhanced electromagnetic wave absorption performance compared to traditional ferrite materials. With the thermal decomposition temperature of 800 °C, the optimal reflection loss value achieved −62.12 dB at 11.85 GHz with thin thickness (2.4 mm), and the bandwidth ranged from 4.1 to 18 GHz with more than 90% of the microwave that could be absorbed. The achieved performance illustrates that the as-prepared porous Co–C core–shell composite shows ...