Wenqiong Ye

Bio: Wenqiong Ye is an academic researcher from East China University of Science and Technology. The author has contributed to research in topics: Composite number & Ultimate tensile strength. The author has an hindex of 3, co-authored 3 publications receiving 23 citations.

Facile fabrication of silica–polymer–graphene collaborative nanostructure-based hybrid materials with high conductivity and robust mechanical performance

Abstract: SiO2@poly(methyl methacrylate)–reduced graphene oxide (SiO2@PMMA–rGO) composites with outstanding thermal stability, robust mechanical performance and excellent conductivity have been prepared by dispersion polymerization and electrostatic assembly based colloidal blending. The simultaneous construction of well-segregated silica structures and interconnected graphene networks, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between the fillers and the PMMA matrix, endowing the resultant composite with high performance. Specifically, compared to the host polymer, the composite with collaborative structure exhibits high thermal stability, i.e. the decomposition temperature increases by 80 °C and shows robust mechanical properties with a 108% increase in modulus and a 125% improvement in hardness. Besides, an ultra-low percolation threshold of 0.23 vol% is also achieved and the electrical conductivity reached 15.1 S m−1 with only 2.7 vol% graphene loading, which is ∼8 orders of magnitude higher than that for SiO2–PMMA–rGO (where SiO2, PMMA and rGO were simply compounded without forming synergetic structures) with the same rGO loading. These results demonstrate that the SiO2@PMMA–rGO composite has great potential to be applied as mechanical, thermal, and electrical materials.

Surface modified nano calcium carbonate with core-shell structure and preparation method thereof

Abstract: The invention relates to surface modified nano calcium carbonate with a core-shell structure and a preparation method thereof. The preparation method comprises the following steps: (1) firstly pre-modifying the surface of nano calcium carbonate with fatty acid; and (2) then adding acrylic monomer, conducting surface coating modification on the nano calcium carbonate by a precipitation polymerization method, and regulating and controlling reaction conditions to obtain the surface modified nano calcium carbonate with the core-shell structure. A polymer modification coating on the nano calcium carbonate prepared by the preparation method can effectively reduce agglomeration of calcium carbonate particles, and contains active unsaturated double bonds which can greatly increase the interface bonding force between the particles and a matrix. Compared with unmodified nano calcium carbonate, the surface modified nano calcium carbonate is obviously improved in dispersibility and compatibility in the matrix. The precipitation polymerization method employed in the preparation method is simple, convenient and safe to operate, and a reaction solvent consists of water and ethyl alcohol, causes no pollution to the environment, and is low in energy consumption and suitable for industrial production.

Preparation of Calcium Carbonate@Methyl Methacrylate Nanoparticles by Seeded-Dispersion Polymerization for High Performance Polyvinyl Chloride Nanocomposites

Abstract: Calcium carbonate@methyl methacrylate-polyvinyl chloride (CaCO3@PMMA–PVC) nanocomposites with outstanding mechanical performance have been successfully prepared. Precise control over the CaCO3 surface modification via a green, facile, and reproducible seed dispersion polymerization, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between components, endowing the resultant composite with high performance. Specifically, the maximum tensile strength of PVC composites was achieved when the addition of CaCO3@PMMA NPs is 4 wt %, and the grafting content is 25%. Compared to pure PVC (P-PVC), the composite shows robust mechanical properties with a 116.7% increase in modulus and a 57.0% improvement in hardness.

Gas Barrier Performance of Graphene/Polymer Nanocomposites

Abstract: Due to its exceptionally outstanding electrical, mechanical and thermal properties, graphene is being explored for a wide array of applications and has attracted enormous academic and industrial interest. Graphene and its derivatives have also been considered as promising nanoscale fillers in gas barrier application of polymer nanocomposites (PNCs). In this review, recent research and development of the utilization of graphene and its derivatives in the fabrication of nanocomposites with different polymer matrices for barrier application are explored. Most synthesis methods of graphene-based PNCs are covered, including solution and melt mixing, in situ polymerization and layer-by-layer process. Graphene layers in polymer matrix are able to produce a tortuous path which works as a barrier structure for gases. A high tortuosity leads to higher barrier properties and lower permeability of PNCs. The influence of the intrinsic properties of these fillers (graphene and its derivatives) and their state of dispersion in polymer matrix on the gas barrier properties of graphene/PNCs are discussed. Analytical modeling aspects of barrier performance of graphene/PNCs are also reviewed in detail. We also discuss and address some of the work on mixed matrix membranes for gas separation.

Highly enhanced thermal conductivity of epoxy composites by constructing dense thermal conductive network with combination of alumina and carbon nanotubes

Abstract: Achieving highly out-plane TC composites by building thermal conductive network at possible low content of conductive fillers is crucial and urgent to realize miniaturization, integration, and high-power density of electronic devices. In this study, highly thermal conductive composites based on pre-selected size of micro-Al2O3 (20 μm and 70 μm), acidified MWCNTs and silica nanoparticles (SiO2 NPs) are fabricated via a facile mixing process. Enhanced thermal conductive network was constructed by small functionalized Al2O3 (f-Al2O3) particles gap filling between large f-Al2O3 particles and the MWCNTs connection with adjacent f-Al2O3 particles. SiO2 NPs are used to avoid the sedimentation of f-Al2O3 particles and improve the dispersion of MWCNTs. The obtained composites show very high out-plane TC (1.73 W·m−1·K−1) at only 60 wt% Al2O3 (20 μm/70 μm: mass fraction, 1/3), 3 wt% MWCNTs and 8 wt% SiO2. It is attributed to the synergistic effect of different size of f-Al2O3 and the MWCNTs to form the dense thermal conduction path. The high out-plane TC and low electric conductivity provide this material great potential as candidate for heat dissipation parts in electronic devices.