The Experts below are selected from a list of 20430 Experts worldwide ranked by ideXlab platform
Qiang Fu - One of the best experts on this subject based on the ideXlab platform.
-
A novel route towards tunable piezoresistive behavior in conductive polymer composites: Addition of insulating filler with different size and surface characteristics
Composites Part A: Applied Science and Manufacturing, 2017Co-Authors: Yi Zhou, Hua Deng, Yan Zhou, Qiang FuAbstract:The morphology of conductive network and their Interfacial Interaction with polymer matrix is thought as the key influential issues for the pressure/strain sensing behavior of conductive polymer composites (CPCs). The surface characteristics and size of these secondary insulating fillers should significantly influence the pressure/strain sensing behavior due to its influence on the morphology of conductive network and Interfacial Interaction between filler and polymer matrix. Herein, insulating SiO2with different size and surface characteristics are incorporated into carbon black (CB)/silicon rubber (SR) composites to modify its piezo-resistive behavior. The conductivity of CB/SiO2/SR composites with nanoscale and hydrophobic SiO2changes by several orders of magnitude, with more linear proportional to applied pressure and better stability under long term cyclic pressure due to better dispersion and stronger Interfacial Interaction. Through such simple method, high-performance piezo-resistive sensors could be fabricated with reversible piezo-resistivity, large pressure application (pressure below 2500 kPa) and tunable piezo-resistive sensitivity.
-
Molecular dynamics simulations of orientation induced Interfacial enhancement between single walled carbon nanotube and aromatic polymers chains
Composites Part A: Applied Science and Manufacturing, 2015Co-Authors: Bowen Yu, Sirui Fu, Hongwei Bai, Nan Ying Ning, Zhiqiang Wu, Qiang FuAbstract:In this work, molecular dynamics simulations were utilized to probe the Interfacial enhancement between aromatic polymers and single walled carbon nanotube (SWCNT) induced by molecular orientation. Two aromatic polymers, polyphenylene sulfide (PPS) and polystyrene (PS) were chosen for comparison study. It was found that orientation of polymer chain could bring about an obvious promotion in Interfacial Interaction for both systems. In PPS/SWCNT systems, the increased Interfacial Interaction energy was due to the easy formation of offset π–π stacking, while in PS/SWCNT systems the formation of edge-to-face π–π stacking contributed to the enhancement. Polymer/SWCNT composites were also constructed and a similar Interfacial enhancement was observed as well. The mechanism of the orientation induced enhancement was a combination of forming more π–π stacking and better coating effect. This will help to deepen the understanding of Interfacial Interaction in aromatic polymers/carbon nanotubes composites and guide the fabrication of high performance materials.
-
realizing the enhancement of Interfacial Interaction in semicrystalline polymer filler composites via Interfacial crystallization
Progress in Polymer Science, 2012Co-Authors: Nan Ying Ning, Sirui Fu, Hua Deng, Ke Wang, Wei Zhang, Feng Chen, Qin Zhang, Qiang FuAbstract:Abstract Polymer/filler composites have been widely used in various areas. One of the keys to achieve the high performance of these composites is good Interfacial Interaction between polymer matrix and filler. As a relatively new approach, the possibility to enhance polymer/filler Interfacial Interaction via crystallization of polymer on the surface of fillers, i.e., Interfacial crystallization, is summarized and discussed in this paper. Interfacial crystallization has attracted tremendous interest in the past several decades, and some unique hybrid crystalline structures have been observed, including hybrid shish–kebab and hybrid shish–calabash structures in which the filler served as the shish and crystalline polymer as the kebab/calabash. Thus, the manipulation of the Interfacial crystallization architecture offers a potential highly effective route to achieve strong polymer/filler Interaction. This review is based on the latest development of Interfacial crystallization in polymer/filler composites and will be organized as follows. The structural/morphological features of various Interfacial crystallization fashions are described first. Subsequently, various influences on the final structure/morphology of hybrid crystallization and the nucleation and/or growth mechanisms of crystallization behaviors at polymer/filler interface are reviewed. Then recent studies on Interfacial crystallization induced Interfacial enhancement ascertained by different research methodologies are addressed, including a comparative analysis to highlight the positive role of Interfacial crystallization on the resultant mechanical reinforcement. Finally, a conclusion, including future perspectives, is presented.
Jozsef Nagy - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of Interfacial Interaction in polypropylene/surface treated CaCO3 composites
Composites Part A-applied Science and Manufacturing, 1998Co-Authors: Zoltan Demjen, Bela Pukanszky, Jozsef NagyAbstract:Abstract Interfacial Interactions significantly influence the properties of particulate filled polymers. The adhesion between the particles and the polymer matrix depends on the size (area) of the interface and the strength of the Interaction. While the former quantity is related to the specific surface area of the filler, the strength of the Interaction can be modified by its surface treatment. In the current experiments polypropylene composites were prepared which contained different amounts of filler treated with eight functional trialkoxy silane coupling agents and the routinely used stearic acid, for comparison. Tensile properties of the composites were determined and the effect of Interfacial Interaction was evaluated by semi-empirical equations developed previously. Significant difference was detected in the effect of the various silane coupling agents. Amino functional silanes increase the strength of the Interaction considerably. The other coupling agents reduce the surface tension of the filler, which leads to a decrease in the reversible work of adhesion between the filler and the polymer. These changes result in a decrease in the tensile strength of the composite. The results also prove the validity of the model equations applied. Parameter B, a measure of the strength of the Interaction, was calculated for each silane coupling agent thus quantitatively characterizing their effectiveness.
-
evaluation of Interfacial Interaction in polypropylene surface treated caco3 composites
Composites Part A-applied Science and Manufacturing, 1998Co-Authors: Zoltan Demjen, Bela Pukanszky, Jozsef NagyAbstract:Abstract Interfacial Interactions significantly influence the properties of particulate filled polymers. The adhesion between the particles and the polymer matrix depends on the size (area) of the interface and the strength of the Interaction. While the former quantity is related to the specific surface area of the filler, the strength of the Interaction can be modified by its surface treatment. In the current experiments polypropylene composites were prepared which contained different amounts of filler treated with eight functional trialkoxy silane coupling agents and the routinely used stearic acid, for comparison. Tensile properties of the composites were determined and the effect of Interfacial Interaction was evaluated by semi-empirical equations developed previously. Significant difference was detected in the effect of the various silane coupling agents. Amino functional silanes increase the strength of the Interaction considerably. The other coupling agents reduce the surface tension of the filler, which leads to a decrease in the reversible work of adhesion between the filler and the polymer. These changes result in a decrease in the tensile strength of the composite. The results also prove the validity of the model equations applied. Parameter B, a measure of the strength of the Interaction, was calculated for each silane coupling agent thus quantitatively characterizing their effectiveness.
Jungang Wang - One of the best experts on this subject based on the ideXlab platform.
-
the correlation of Interfacial Interaction and catalytic performance of n doped mesoporous carbon supported cobalt nanoparticles for fischer tropsch synthesis
Journal of Physical Chemistry C, 2014Co-Authors: Yifei Yang, Debao Li, Jungang WangAbstract:The Interfacial Interaction between active species and supports is of significance for the catalytic performance of heterogeneous catalysts. Accordingly, the N-doped mesoporous carbon (NMC) was employed to support cobalt nanoparticles for insight into the nature of Interfacial Interaction and the reactivity of Fischer–Tropsch synthesis (FTS). Through a series of characterization techniques, it is found that the nitrogen incorporated into the carbonaceous framework, especially the sp2-type nitrogen, eventually functions as heterogeneous sites for the nucleation and growth of cobalt species. Owing to the unique structure of NMC supports, a pronounced electron transfer from the NMC supports to cobalt oxide particles takes place at the interface. The solid-state Interfacial Interaction significantly affects the dispersion and reduction behavior of cobalt species on the NMC substrates, resulting in the shift of the reduction peak of small particles toward high temperature, which ultimately shapes an unusual ca...
-
The Correlation of Interfacial Interaction and Catalytic Performance of N-Doped Mesoporous Carbon Supported Cobalt Nanoparticles for Fischer–Tropsch Synthesis
Journal of Physical Chemistry C, 2013Co-Authors: Yifei Yang, Debao Li, Jungang WangAbstract:The Interfacial Interaction between active species and supports is of significance for the catalytic performance of heterogeneous catalysts. Accordingly, the N-doped mesoporous carbon (NMC) was employed to support cobalt nanoparticles for insight into the nature of Interfacial Interaction and the reactivity of Fischer–Tropsch synthesis (FTS). Through a series of characterization techniques, it is found that the nitrogen incorporated into the carbonaceous framework, especially the sp2-type nitrogen, eventually functions as heterogeneous sites for the nucleation and growth of cobalt species. Owing to the unique structure of NMC supports, a pronounced electron transfer from the NMC supports to cobalt oxide particles takes place at the interface. The solid-state Interfacial Interaction significantly affects the dispersion and reduction behavior of cobalt species on the NMC substrates, resulting in the shift of the reduction peak of small particles toward high temperature, which ultimately shapes an unusual ca...
Liqun Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Understanding the structural evolution under the oscillatory shear field to determine the viscoelastic behavior of nanorod filled polymer nanocomposites
Computational Materials Science, 2018Co-Authors: Yangyang Gao, Fengyan Hu, Jun Liu, Youping Wu, Liqun ZhangAbstract:Abstract By taking advantage of the classic coarse-grained molecular dynamics simulation, we have examined the effect of oscillatory shear strain amplitude on the viscoelastic behavior of nanorod (NR) filled polymer nanocomposites (PNCs) by tuning the Interfacial Interaction between polymer and NRs. We have observed the Payne effect (referred to the nonlinear viscoelastic behavior) at strong Interfacial Interaction. Payne-effect magnitude gradually increases with the Interfacial Interaction and the NR volume fraction. To understand the origin of Payne-effect, we examine the NR microstructures and their evolution during the shear field. We find that at low Interfacial Interaction, the probability of forming NR network is nearly unchanged with the shear strain amplitude; while at strong Interfacial Interaction, on the contrary the probability significantly decreases with the shear strain amplitude. We infer that various Interfacial Interactions change the NR network, influencing their evolution behavior under the shear flow. Meanwhile, we calculate the main cluster size and the total number of clusters for the NR network at different shear strain amplitudes, which is consistent with the probability of forming NR network. Thus, the original NR microstructure is significantly broken down under the external shear field, which can also be reflected by the number for polymer-mediated NR network bridged by glassy chains and the connected polymer beads between NRs. In addition, the polymer chains can slip on the filler surface under the shear field. As a result, the observed Payne effect comes from the slippage of the Interfacial chains and breakage of the polymer-mediated NR network bridged by glassy chains at strong Interfacial Interaction. While at low Interfacial Interaction, it exhibits a weak non-linear behavior. Additionally, both reinforcement and Payne-effect magnitude exhibit a linear dependence on the inverse of the aspect ratio of the NRs. At last, different contributions to reinforcement due to hydrodynamic effects, “occluded rubber”, and “filler network” are quantified where the “filler network” is the main contribution. In summary, this work provides some interesting results to help further understand the relationship between the viscoelastic behavior and the NR network under the shear flow.
-
New insight on the Interfacial Interaction between multiwalled carbon nanotubes and elastomers
Composites Science and Technology, 2017Co-Authors: Nan Ying Ning, Youping Wu, Liqun Zhang, Dongliang Cheng, Jianhua Yang, Ming Tian, Wencai Wang, Yonglai LuAbstract:Abstract We studied the effect of the microstructure of multiwalled carbon nanotubes (MWCNTs) on Interfacial Interaction in seven kinds of MWCNT/natural rubber (NR) composites. Unexpectedly, the degree of defects (ID/IG) of MWCNTs was found to play a key role in the Interfacial Interaction of MWCNT/NR composites. The content of bound rubber (BR) of the composites almost linearly increased with the increase in the ID/IG of MWCNTs. Then we studied the Interfacial Interaction between MWCNTs with high degree of defects and NR. Interestingly, the BR of the composites consisted of loosely adsorbed BR (LBR) and tight BR (TBR). TBR occupied about half of the total BR, and cannot be removed by extraction in hot toluene for 48 h. Meanwhile, the mobilities of macromolecules in TBR were more restricted than those in LBR. We discussed in depth the molecular origin of the Interfacial Interaction between defected MWCNTs and NR, and then proposed that LBR was topologically confined by the steps-like structure of defected MWCNTs whereas TBR was principally chemically bonded to MWCNTs. This study provided new insight on the Interfacial Interaction between MWCNTs and NR and thus provides guidance for the preparation of high-performance elastomer composites with strong Interfacial Interaction.
-
enhanced Interfacial Interaction and excellent performance of silica epoxy group functionalized styrene butadiene rubber sbr nanocomposites without any coupling agent
Composites Part B-engineering, 2017Co-Authors: He Qiao, Mingyuan Chao, Junchi Zheng, Xinxin Zhou, Runguo Wang, Liqun ZhangAbstract:Abstract Epoxy group-functionalized styrene-butadiene rubbers (G-ESBRs) with different epoxy group contents were synthesized through emulsion polymerization using glycidyl methacrylate (GMA) as the epoxy group-included monomer, and the silica/G-ESBR nanocomposites without silane coupling agents were prepared. The covalent bonding interfaces, resulting from a ring-opening reaction between the hydroxyl groups on the silica surfaces and the epoxy groups of G-ESBR, were formed during the preparation of the silica/G-ESBR nanocomposites. By increasing the epoxy group content, the number of covalent bonds at the interface increases, contributing to an improvement of the Interfacial Interaction between the G-ESBR and silica and the dispersion of silica, which were verified and analyzed in detail by bound rubber measurement, transmission electron microscopy (TEM) and rubber process analyzer (RPA). The silica/G-ESBR nanocomposites with improved dispersion of silica and Interfacial Interaction showed decreased rolling resistance and increased wet skid resistance. The mechanical properties of the nanocomposites were greatly improved with increasing epoxy group contents. The highest tensile strength reached 29.4 MPa at a GMA content of 4.8 wt%, a 55.6% increase compared with that of the nanocomposite without epoxy group.
-
morphology Interfacial Interaction and properties of a novel bioelastomer reinforced by silica and carbon black
Journal of Applied Polymer Science, 2013Co-Authors: Runguo Wang, Liqun Zhang, Xinxin Zhou, Joseph John KuligAbstract:A novel poly(diisoamyl itaconate-co-isoprene) (PDII) bioelastomer was prepared by redox emulsion polymerization based on itaconic acid, isoamyl alcohol, and isoprene. Carbon black (CB), silica, and silica with coupling agent (bis(3-(triethoxysilyl)-propyl)tetrasulfide [TESPT]-silica) were used as fillers to reinforce the novel elastomer. The difference in morphology, Interfacial Interaction, thermal properties, and mechanical properties of PDII composites filled with different fillers was studied. The homogeneous dispersion of silica and CB in the PDII matrix was confirmed by scanning electron microscopy and transmission electron microscopy. Silica had homogenous dispersion possibly because of the formation of hydrogen bonds between the silica silanols and the PDII macromolecular chains. PDII/silica and PDII/TESTP-silica have lower crosslink density and crosslinking rate than PDII/CB owing to the adsorption of accelerators by the silanols in the silica surfaces. PDII/silica had comparable tensile strength but higher elongation at break than PDII/CB. The tensile strength of PDII/TESPT-silica was higher than PDII/CB and PDII/silica. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
-
effects of Interfacial Interaction on chain dynamics of rubber graphene oxide hybrids a dielectric relaxation spectroscopy study
RSC Advances, 2013Co-Authors: Siwu Wu, Zhenghai Tang, Liqun ZhangAbstract:Hybrids consisting of graphene oxide (GO) sheets and butadiene-styrene-vinyl pyridine rubber (VPR) were prepared by a co-coagulation process with different flocculants, hydrogen chloride and calcium chloride, in order to form two kinds of bonding interfaces, namely ionic bonding (HVPR) and hydrogen bonding (CaVPR) interfaces. To reveal the effects of Interfacial Interaction on the chain dynamics, the dielectric relaxation spectra of these hybrids have been investigated. The results show that all hybrids exhibit two distinct relaxation processes, segmental relaxation and Interfacial relaxation. The concentration of GO has no impact on the segmental dynamics of CaVPR, but the segmental dynamics of HVPR slow down at 1.5 vol% of GO. Meanwhile, the segmental relaxation of HVPR is always a little faster than its CaVPR counterpart. In the temperature range of 5–35 °C, a new relaxation mode, which is slower than the segmental relaxation and attributed to the interphase with restricted chain dynamics, has been observed for all the hybrids with a GO loading lower than 2.5 vol%. The Interfacial relaxation time of HVPR decreases with decreasing GO concentration. However, in CaVPR it first decreases and then increases with decreasing GO concentration. Most interestingly, the Interfacial relaxation of HVPR is slower than that for CaVPR. The dielectric strength (Δe), the calculated fragility parameter and the effective activation enthalpy of the Interfacial chains in HVPR are always higher than those in CaVPR with the same GO concentration. All the evidence indicates the stronger Interfacial Interactions in HVPR than in CaVPR.
Nan Ying Ning - One of the best experts on this subject based on the ideXlab platform.
-
New insight on the Interfacial Interaction between multiwalled carbon nanotubes and elastomers
Composites Science and Technology, 2017Co-Authors: Nan Ying Ning, Youping Wu, Liqun Zhang, Dongliang Cheng, Jianhua Yang, Ming Tian, Wencai Wang, Yonglai LuAbstract:Abstract We studied the effect of the microstructure of multiwalled carbon nanotubes (MWCNTs) on Interfacial Interaction in seven kinds of MWCNT/natural rubber (NR) composites. Unexpectedly, the degree of defects (ID/IG) of MWCNTs was found to play a key role in the Interfacial Interaction of MWCNT/NR composites. The content of bound rubber (BR) of the composites almost linearly increased with the increase in the ID/IG of MWCNTs. Then we studied the Interfacial Interaction between MWCNTs with high degree of defects and NR. Interestingly, the BR of the composites consisted of loosely adsorbed BR (LBR) and tight BR (TBR). TBR occupied about half of the total BR, and cannot be removed by extraction in hot toluene for 48 h. Meanwhile, the mobilities of macromolecules in TBR were more restricted than those in LBR. We discussed in depth the molecular origin of the Interfacial Interaction between defected MWCNTs and NR, and then proposed that LBR was topologically confined by the steps-like structure of defected MWCNTs whereas TBR was principally chemically bonded to MWCNTs. This study provided new insight on the Interfacial Interaction between MWCNTs and NR and thus provides guidance for the preparation of high-performance elastomer composites with strong Interfacial Interaction.
-
Molecular dynamics simulations of orientation induced Interfacial enhancement between single walled carbon nanotube and aromatic polymers chains
Composites Part A: Applied Science and Manufacturing, 2015Co-Authors: Bowen Yu, Sirui Fu, Hongwei Bai, Nan Ying Ning, Zhiqiang Wu, Qiang FuAbstract:In this work, molecular dynamics simulations were utilized to probe the Interfacial enhancement between aromatic polymers and single walled carbon nanotube (SWCNT) induced by molecular orientation. Two aromatic polymers, polyphenylene sulfide (PPS) and polystyrene (PS) were chosen for comparison study. It was found that orientation of polymer chain could bring about an obvious promotion in Interfacial Interaction for both systems. In PPS/SWCNT systems, the increased Interfacial Interaction energy was due to the easy formation of offset π–π stacking, while in PS/SWCNT systems the formation of edge-to-face π–π stacking contributed to the enhancement. Polymer/SWCNT composites were also constructed and a similar Interfacial enhancement was observed as well. The mechanism of the orientation induced enhancement was a combination of forming more π–π stacking and better coating effect. This will help to deepen the understanding of Interfacial Interaction in aromatic polymers/carbon nanotubes composites and guide the fabrication of high performance materials.
-
realizing the enhancement of Interfacial Interaction in semicrystalline polymer filler composites via Interfacial crystallization
Progress in Polymer Science, 2012Co-Authors: Nan Ying Ning, Sirui Fu, Hua Deng, Ke Wang, Wei Zhang, Feng Chen, Qin Zhang, Qiang FuAbstract:Abstract Polymer/filler composites have been widely used in various areas. One of the keys to achieve the high performance of these composites is good Interfacial Interaction between polymer matrix and filler. As a relatively new approach, the possibility to enhance polymer/filler Interfacial Interaction via crystallization of polymer on the surface of fillers, i.e., Interfacial crystallization, is summarized and discussed in this paper. Interfacial crystallization has attracted tremendous interest in the past several decades, and some unique hybrid crystalline structures have been observed, including hybrid shish–kebab and hybrid shish–calabash structures in which the filler served as the shish and crystalline polymer as the kebab/calabash. Thus, the manipulation of the Interfacial crystallization architecture offers a potential highly effective route to achieve strong polymer/filler Interaction. This review is based on the latest development of Interfacial crystallization in polymer/filler composites and will be organized as follows. The structural/morphological features of various Interfacial crystallization fashions are described first. Subsequently, various influences on the final structure/morphology of hybrid crystallization and the nucleation and/or growth mechanisms of crystallization behaviors at polymer/filler interface are reviewed. Then recent studies on Interfacial crystallization induced Interfacial enhancement ascertained by different research methodologies are addressed, including a comparative analysis to highlight the positive role of Interfacial crystallization on the resultant mechanical reinforcement. Finally, a conclusion, including future perspectives, is presented.