The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform

Jinsong Leng - One of the best experts on this subject based on the ideXlab platform.

  • structural design of flexible au electrode to enable shape memory polymer for Electrical Actuation
    Smart Materials and Structures, 2015
    Co-Authors: Ming Lei, Chao Zhao, Jinsong Leng
    Abstract:

    An effective resistive Joule heating approach was conducted to improve the Electrical Actuation and shape-recovery performance of a shape memory polymer (SMP) nanocomposite. Two types of gold (Au) film patterns were deposited to be used as electrodes to drive thermal-responsive SMPs and achieve a uniform temperature distribution during electro-activated shape recovery. Furthermore, the sensing capability of the Au electrode to both mechanical and thermal stimuli applied to the SMP nanocomposite was experimentally investigated and theoretically analyzed. It was found that the change in the Electrical resistance of the Au electrode could be used as an indication of shape-recovery performance. The linear response of the Electrical resistance to strain was identified mainly due to the opening/closing of microcracks and their propagations in the Au electrodes during out-of-plane deformations. With an increment of thermomechanical bending cycles, the Electrical resistance was increased exponentially, but it returned back to the original reading when the SMP nanocomposite returned back to its permanent shape. Finally, the flexible Au electrode enabled the Actuation of the SMP nanocomposite under an electric voltage of 13.4 V, with an improved shape-recovery performance and temperature distribution.

  • Electrical Actuation properties of reduced graphene oxide paper epoxy based shape memory composites
    Composites Science and Technology, 2015
    Co-Authors: Wenxin Wang, Jinsong Leng, Yanju Liu, Dongyan Liu, Debes Bhattacharyya
    Abstract:

    Abstract In order to explore the enabled design principles of Electrically driven epoxy-based shape memory (ER) composites, reduced graphene oxide paper (RGOP) was used for manufacturing the material. Shape memory effect is induced by Electrical resistive heating of RGOP possessing excellent heat conductive property and serving as a conductive layer to transmit heat to the polymer. The temperature distribution and shape recovery behavior of the composite have been recorded with infrared video. The investigation on shape recovery behavior of reduced graphene oxide paper/epoxy-based shape memory composites (RGOP/ER) reveals that the shape recovery speed increases with increased applied voltage. It is worth noting that the recoverability of the composite is approximately 100% taking only 5 s under 6 V, which is more energy saving than the previously reported data. The Electrical Actuation shape recovery rate of the composite can be controlled by programming the synergistic effect between the mass ratio and the applied voltage. This work provides a feasible route to construct efficient Electrically actuated shape memory composites and to expand their potential applications.

  • surface grafting of carbon fibers with artificial silver nanoparticle decorated graphene oxide for high speed Electrical Actuation of shape memory polymers
    Journal of Applied Polymer Science, 2014
    Co-Authors: Shipeng Zhu, Yunhua Yang, Weimin Huang, Jinsong Leng
    Abstract:

    Poor heat conduction in the interface between the carbon fiber and polymer matrix is a problem in the Actuation of shape-memory polymer (SMP) composites by Joule heating. In this study, we investigated the effectiveness of grafting silver-nanoparticle-decorated graphene oxide (GO) onto carbon fibers to improve the electrothermal properties and Joule-heating-activated shape recovery of SMP composites. Self-assembled GO was grafted onto carbon fibers to enhance the bonding of the carbon fibers with the polymeric matrix via van der Waal's forces and covalent crosslinking, respectively. Silver nanoparticles were further self-assembled and deposited to decorate the GO assembly, which was used to decrease the thermal dissimilarity and facilitate heat transfer from the carbon fiber to the polymer matrix. The carbon fiber was incorporated with SMP to achieve the shape recovery induced by Joule heating. We found that the silver-nanoparticle-decorated GO helped us achieve a more uniform temperature distribution in the SMP composites compared to those without decoration. Furthermore, the shape-recovery behavior and temperature profile during the Joule heating of the SMP composites were characterized and compared. A unique synergistic effect of the carbon fibers and silver-nanoparticle-decorated GO was achieved to enhance the heat transfer and a higher speed of Actuation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41673.

  • synergistic effect of ag nanoparticle decorated graphene oxide and carbon fiber on Electrical Actuation of polymeric shape memory nanocomposites
    Smart Materials and Structures, 2014
    Co-Authors: Fei Liang, Jihua Gou, Jinsong Leng
    Abstract:

    This study reports an effective approach of significantly improving Electrical properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by Electrically resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, respectively. A layer of Ag nanoparticles was synthesized from Ag+ solution and chemically deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the Electrical conductivity. The experimental results reveal that the Electrical conductivity of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the Electrically induced shape memory effect of the SMP nanocomposite was achieved, and the temperature distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electro-activated SMP nanocomposites and the resistive Joule heating was viable at a low Electrical voltage below 10 V.

  • functionally graded and self assembled carbon nanofiber and boron nitride in nanopaper for Electrical Actuation of shape memory nanocomposites
    Composites Part B-engineering, 2014
    Co-Authors: Weimin Huang, Jinsong Leng
    Abstract:

    Abstract The present work studies the synergistic effect of self-assembled carbon nanofiber (CNF) and boron nitride (BN) nanopaper on the Electrical and thermal properties, and electro-activated shape memory effect (SME) of polymeric shape memory nanocomposites. CNF and BN are first self-assembled on carbon fibers by means of deposition at a high pressure to form functionally graded nanopaper with high Electrical and thermal conductivity. The resultant nanopaper is then coated on the surface of shape memory polymer (SMP) to enable Actuation by means of Joule heating via passing an Electrical current through CNFs and carbon fiber. Here, BN is introduced to improve the thermal conductivity and large dissimilarity of the nanocomposite for enhanced heat transfer and electric-activated shape recovery.

Jihua Gou - One of the best experts on this subject based on the ideXlab platform.

  • Electrical Actuation and shape memory behavior of polyurethane composites incorporated with printed carbon nanotube layers
    Composites Science and Technology, 2017
    Co-Authors: Xin Wang, John Sparkman, Jihua Gou
    Abstract:

    Abstract In this study, a novel digitally controlled spraying-evaporation deposition modeling process was used to deposit carbon nanotube (CNT) layers on shape memory polymer (SMP) films. This system is able to produce CNT layers with variable thicknesses and arbitrary patterns on defined locations. The study on the Electrical properties of composite films revealed that the composites with 50 CNT layers exhibited the lowest sheet resistance of 28.7 Ω/sq. Accordingly, the resistive heating performance of the fabricated composites was investigated at different power densities. The maximum surface temperature can be adjusted by simply tuning the numbers of printed CNT layers. Particularly, the even temperature distribution or temperature gradient could be realized on the surface of composites through modifying the design of printed CNT patterns. The study on the shape memory effect of the CNT/SMP composites indicated that the CNT/SMP composites can be actuated by the resistive heating of the printed CNT layers without an external heater. The shape recoverability of the composites was approximately 100% taking 30s under 40 V. It is worth noting that through programming the number of printed CNT layers at different locations, the shape recovery rate could be controlled and localized Actuation with the desired recovery ratio was achieved. The high efficiency of heating coupling with wide adjustability of surface temperature and shape recovery ratio at specified locations make the fabricated CNT/SMP composite a promising candidate for various heating and Actuation applications.

  • synergistic effects of carboxylic acid functionalized carbon nanotube and nafion silica nanofiber on Electrical Actuation efficiency of shape memory polymer nanocomposite
    Composites Part B-engineering, 2016
    Co-Authors: Jinying Yin, Jihua Gou, David Hui
    Abstract:

    Synergistic effects of self-assembled carboxylic acid-functionalized carbon nanotube (CNT) and nafion/silica nanofiber on the electro-activated shape recovery behavior of shape memory polymer (SMP) nanocomposite were investigated. Carboxylic acid-functionalized CNTs were self-assembled onto the carbon fiber mat to enhance their bonding reliability and achieve efficient Electrical Actuation for SMP matrix. Nafion/silica nanofibers were electrospun onto surfaces of the carbon fiber mat to prevent Electrically resistive heat dissipation. The combination of Electrically/thermally conductive CNTs and thermally resistive nafion/silica nanofibers results in improvement for both Electrically induced shape recovery and Actuation efficiency in the SMP nanocomposite.

  • Controlling Au electrode patterns for simultaneously monitoring Electrical Actuation and shape recovery in shape memory polymer
    Composites Part B: Engineering, 2015
    Co-Authors: Ming Lei, Yongtao Yao, Chao Zhao, Jihua Gou, David Hui
    Abstract:

    This paper presents an effective approach to achieve efficient Electrical Actuation and monitoring of shape recovery based on patterned Au electrodes on shape memory polymer (SMP). The Electrically responsive shape recovery behavior was characterized and monitored by the evolution change in Electrical resistance of patterned Au electrode. Both Electrical Actuation and temperature distribution in the SMP have been improved by optimizing the Au electrode patterns. The Electrically actuated shape recovery behavior and temperature evolution during the Actuation were monitored and characterized. The resistance changes could be used to detect beginning/finishing points of the shape recovery. Therefore, the Au electrode not only significantly enhances the Electrical Actuation performance to achieve a fast Electrical Actuation, but also enables the resistance signal to detect the free recovery process.

  • synergistic effect of ag nanoparticle decorated graphene oxide and carbon fiber on Electrical Actuation of polymeric shape memory nanocomposites
    Smart Materials and Structures, 2014
    Co-Authors: Fei Liang, Jihua Gou, Jinsong Leng
    Abstract:

    This study reports an effective approach of significantly improving Electrical properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by Electrically resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, respectively. A layer of Ag nanoparticles was synthesized from Ag+ solution and chemically deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the Electrical conductivity. The experimental results reveal that the Electrical conductivity of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the Electrically induced shape memory effect of the SMP nanocomposite was achieved, and the temperature distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electro-activated SMP nanocomposites and the resistive Joule heating was viable at a low Electrical voltage below 10 V.

  • self assembled multi layered carbon nanofiber nanopaper for significantly improving Electrical Actuation of shape memory polymer nanocomposite
    Composites Part B-engineering, 2014
    Co-Authors: Fei Liang, Yongtao Yao, Jihua Gou, David Hui
    Abstract:

    This study presents an effective approach to significantly improve the Electrical properties of shape memory polymer (SMP) nanocomposites that show Joule heating triggered shape recovery. Carbon nanofibers (CNFs) were self-assembled to form multi-layered nanopaper to enhance the bonding and shape recovery behavior of SMP, respectively. It was found that both glass transition temperature (Tg) and Electrical properties of the SMP nanocomposites have been improved by incorporating multi-layers of selfassembled nanopapers. The Electrically actuated shape recovery behavior and the temperature profile during the Actuation were monitored and characterized at a voltage of 30 V.

Fei Liang - One of the best experts on this subject based on the ideXlab platform.

  • synergistic effect of ag nanoparticle decorated graphene oxide and carbon fiber on Electrical Actuation of polymeric shape memory nanocomposites
    Smart Materials and Structures, 2014
    Co-Authors: Fei Liang, Jihua Gou, Jinsong Leng
    Abstract:

    This study reports an effective approach of significantly improving Electrical properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by Electrically resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, respectively. A layer of Ag nanoparticles was synthesized from Ag+ solution and chemically deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the Electrical conductivity. The experimental results reveal that the Electrical conductivity of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the Electrically induced shape memory effect of the SMP nanocomposite was achieved, and the temperature distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electro-activated SMP nanocomposites and the resistive Joule heating was viable at a low Electrical voltage below 10 V.

  • self assembled multi layered carbon nanofiber nanopaper for significantly improving Electrical Actuation of shape memory polymer nanocomposite
    Composites Part B-engineering, 2014
    Co-Authors: Fei Liang, Yongtao Yao, Jihua Gou, David Hui
    Abstract:

    This study presents an effective approach to significantly improve the Electrical properties of shape memory polymer (SMP) nanocomposites that show Joule heating triggered shape recovery. Carbon nanofibers (CNFs) were self-assembled to form multi-layered nanopaper to enhance the bonding and shape recovery behavior of SMP, respectively. It was found that both glass transition temperature (Tg) and Electrical properties of the SMP nanocomposites have been improved by incorporating multi-layers of selfassembled nanopapers. The Electrically actuated shape recovery behavior and the temperature profile during the Actuation were monitored and characterized at a voltage of 30 V.

  • synergistic effect of self assembled carbon nanopaper and multi layered interface on shape memory nanocomposite for high speed Electrical Actuation
    Journal of Applied Physics, 2014
    Co-Authors: Fei Liang, Jihua Gou, Weimin Huang, Jinsong Leng
    Abstract:

    The synergistic effect of self-assembled carbon nanofiber (CNF) nanopaper and the multi-layered interface on the Electrical properties and electro-activated recovery behavior of shape memory polymer (SMP) nanocomposites is investigated. The CNFs were self-assembled by deposition into sheets of multi-layered nanopaper form to significantly enhance the bonding strength between the nanopaper and SMP via van der Waals force. The self-assembled multi-layered CNF nanopaper resulted in improved Electrical conductivity and temperature distribution in the SMP nanocomposites. This not only significantly enhances the reliability of bonding between the nanopaper and the SMP, resulting in an improved recovery ratio, but also provides high speed Electrical Actuation.

  • Electrical Actuation and shape recovery control of shape memory polymer nanocomposites
    International Journal of Smart and Nano Materials, 2013
    Co-Authors: Fei Liang, Jihua Gou, Robert Sivilli, Bob Mabbott
    Abstract:

    Shape-memory polymers (SMPs) are one of the most popular smart materials due to their light weight and high elastic deformation capability. The synergistic effect of carbon nanofiber (CNF) and carbon nanofiber paper (CNFP) on the electro-Actuation of SMP nanocomposites was studied. The Electrical conductivity of SMPs was significantly improved by incorporating CNF and CNFP into them. The dynamic mechanical analysis result reveals good thermal stability of SMP nanocomposites even after they were mixed with CNFs. A vision-based control system is designed to precisely control the shape recovery of SMP composites. Any quasi-state shape between the permanent shape and a temporary shape can be achieved by adjusting the Electrical energy input. Experimental results demonstrated that (1) compared with the baseline material, the full recovery time of the SMP nanocomposites was decreased by 1000% to less than 80 s; (2) a good repeatability was shown in the developed vision system in 10 experimental trials and the a...

  • Nanopaper enabled shape-memory nanocomposite with vertically aligned nickel nanostrand: controlled synthesis and Electrical Actuation
    Soft Matter, 2011
    Co-Authors: Haibao Lu, Fei Liang
    Abstract:

    The present work studies the synergistic effect of self-assembly multi-walled carbon nanotube (MWCNT) nanopaper and sub-micro nickel nanostrand on the Electrical properties and electro-active recovery behavior of shape memory polymer (SMP) nanocomposite. The combination of MWCNT nanopaper and nickel nanostrand is used to improve the Electrical and thermal conductivities of the SMP nanocomposite. The Electrical MWCNT nanopaper was coated on the surface to achieve the shape recovery of the SMP nanocomposite induced by electricity. Electromagnetic nickel nanostrands were blended with and, vertically aligned into the SMP resin in a magnetic field, to improve the thermal conductivity. The vertically aligned nickel nanostrands will facilitate the heat transfer from the nanopaper to the underlying SMP composite to accelerate the Electrical Actuation. Furthermore, they have little negative effect on recovery behavior, resulting in the nanocomposite having an approximately 100% recovery ratio undergoing cyclic deformation.

David Hui - One of the best experts on this subject based on the ideXlab platform.

Haibao Lu - One of the best experts on this subject based on the ideXlab platform.

  • functionally graded carbon nanotube and nafion silica nanofibre for Electrical Actuation of carbon fibre reinforced shape memory polymer
    Pigment & Resin Technology, 2016
    Co-Authors: Haibao Lu
    Abstract:

    Purpose – This paper aims to study the synergistic effect of self-assembled carboxylic acid-functionalised carbon nanotube (CNT) and nafion/silica nanofibre nanopaper on the electro-activated shape memory effect (SME) and shape recovery behaviour of shape memory polymer (SMP) nanocomposite. Design/methodology/approach – Carboxylic acid-functionalised CNT and nafion/silica nanofibre are first self-assembled onto carbon fibre by means of deposition and electrospinning approaches, respectively, to form functionally graded nanopaper. The combination of carbon fibre and CNT is introduced to enable the Actuation of the SME in SMP by means of Joule heating at a low electric voltage of 3.0-5.0 V. Findings – Nafion/silica nanofibre is used to improve the shape recovery behaviour and performance of the SMP for enhanced heat transfer and Electrical Actuation effectiveness. Low Electrical voltage Actuation and high Electrical Actuation effectiveness of 32.5 per cent in SMP has been achieved. Research limitations/impl...

  • Carbon-based reinforcement in shape-memory polymer composite for Electrical Actuation
    Pigment & Resin Technology, 2013
    Co-Authors: Haibao Lu
    Abstract:

    Purpose – This article aims to present a systematic and up-to-date account of carbon-based reinforcements, including carbon nanotube (CNT), carbon nanofibre (CNF), carbon black (CB), carbon fibre (CF) and grapheme, in shape-memory polymer (SMP) for Electrical Actuation. Design/methodology/approach – Studies exploring carbon-based reinforcement in SMP composites for Electrically conductive performance and Joule heating triggered shape recovery have been included, especially for the principle design, characterisation and shape recovery behaviour, making the article a comprehensive account of the systemic progress in SMP composite incorporating conductive carbon reinforcement. Findings – SMPs are fascinating materials and have attracted great academic and industrial attention owing to their significant macroscopic shape deformation in the presence of an appropriate stimulus. The working mechanisms, the physico requirements and the theoretical origins of the different types of carbon-based reinforcement SMP c...

  • Nanopaper enabled shape-memory nanocomposite with vertically aligned nickel nanostrand: controlled synthesis and Electrical Actuation
    Soft Matter, 2011
    Co-Authors: Haibao Lu, Fei Liang
    Abstract:

    The present work studies the synergistic effect of self-assembly multi-walled carbon nanotube (MWCNT) nanopaper and sub-micro nickel nanostrand on the Electrical properties and electro-active recovery behavior of shape memory polymer (SMP) nanocomposite. The combination of MWCNT nanopaper and nickel nanostrand is used to improve the Electrical and thermal conductivities of the SMP nanocomposite. The Electrical MWCNT nanopaper was coated on the surface to achieve the shape recovery of the SMP nanocomposite induced by electricity. Electromagnetic nickel nanostrands were blended with and, vertically aligned into the SMP resin in a magnetic field, to improve the thermal conductivity. The vertically aligned nickel nanostrands will facilitate the heat transfer from the nanopaper to the underlying SMP composite to accelerate the Electrical Actuation. Furthermore, they have little negative effect on recovery behavior, resulting in the nanocomposite having an approximately 100% recovery ratio undergoing cyclic deformation.

  • Magnetically aligned carbon nanotube in nanopaper enabled shape-memory nanocomposite for high speed Electrical Actuation
    Applied Physics Letters, 2011
    Co-Authors: Haibao Lu, Jihua (Jan) Gou, Jinsong Leng, Shanyi Du
    Abstract:

    A new shape-memory nanocomposite that exhibits rapid Electrical Actuation capabilities is fabricated by incorporating self-assembly multiwalled carbon nanotube (MWCNT) nanopaper and magnetic CNTs into a styrene-based shape-memory polymer (SMP). The MWCNT nanopaper was coated on the surface to give high Electrical conductivity to SMP. Electromagnetic CNTs were blended with and, vertically aligned into the SMP resin upon a magnetic field, to facilitate the heat transfer from the nanopaper to the underlying SMP. This not only significantly enhances heat transfer but also gives high speed Electrical Actuation.