Co-reporter:Tao Huang, Hao Yu, Hongzhi Wang, Qinghong Zhang, and Meifang Zhu
The Journal of Physical Chemistry C 2016 Volume 120(Issue 47) pp:26600-26608
Publication Date(Web):November 7, 2016
DOI:10.1021/acs.jpcc.6b07382
Mechanical energy harvesting is a green technology with great potential for applications in self-powered portable electronics, wireless sensing, implanted devices, and security systems. We have previously reported a triboelectric nanogenerator (TENG) fabricated from poly(vinylidene fluoride) (PVDF) electrospun nanofibers. This device enabled harvesting of mechanical energy and exhibited an output voltage of 210 V. Here we report doping of the PVDF nanofibers with silica (SiO2) nanoparticles, which increased the output performance of the resultant TENG devices. The output peak to peak voltage was increased to 370 V as the SiO2 nanoparticles content was increased to 0.6 wt % and then declined with further increases in SiO2 content. Hydrophobic SiO2 nanoparticles (mSiO2) were prepared by an octanol treatment and markedly increased the performances of the resulting TENG devices. An output peak to peak voltage of up to 430 V was achieved with 0.8 wt % mSiO2 representing a 48% increase over the value obtained from a PVDF–0.8 wt % SiO2 nanofiber-based TENG. On the basis of our high performance TENG devices, we developed a self-powered digital thermometer for temperature measurement without a battery.
Co-reporter:Tao Huang, Cheng Wang, Hao Yu, Hongzhi Wang, Qinghong Zhang, Meifang Zhu
Nano Energy 2015 Volume 14() pp:226-235
Publication Date(Web):May 2015
DOI:10.1016/j.nanoen.2015.01.038
•Nanofiber with secondary nanostructures improved the TENG performance.•The piezoelectric effect of PVDF nanofibers has been systematically investigated.•Breathable nanofiber meets the user requirements of flexibility and wearability.•Conductive wearable fabrics further enhanced the output power of the TENG.A simple-to-fabricate, high-performance, wearable all-fiber triboelectric nanogenerator (TENG)-based insole composed of electrospun piezoelectric polyvinylidene fluoride (PVDF) nanofibers sandwiched between a pair of conducting fabric electrodes that effectively harvests energy during human walking is reported. The surface of the nanofibers is roughened with secondary nanostructure to enhance insole performance. The maximum output voltage, instantaneous power and output current from the insole reach 210 V, 2.1 mW and 45 μA, respectively. The role of the piezoelectric effect in the electrospun PVDF nanofibers in this TENG-based insole is then systematically investigated. This device is shown to be a reliable power source that can be used to light up 214 serially connected light-emitting diodes directly. The soft fiber-based electric power generator demonstrated in this paper is capable of meeting the requirements of wearable devices because of its efficient energy-conversion performance, high durability, user comfort, and low cost.
Co-reporter:Anhui Wang;Yunna Gan;Yuan Liu;Min Zhang;Baixiang Cheng;Fang Wang;Huixia Wang;Juanjuan Yan
Journal of Biomedical Materials Research Part A 2012 Volume 100A( Issue 6) pp:1505-1511
Publication Date(Web):
DOI:10.1002/jbm.a.34034
Abstract
Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBV) is a nature-derived polyester with potential application in tissue engineering scaffolds. However, PHBV is associated with disadvantages including high brittleness, slow degradation, high hydrophobicity, and unsatisfactory biocompatibility. In this study, we sought to improve the properties of PHBV by blending it with Ecoflex, a synthetic biopolyester with a high flexibility, fast degradation, and comparatively higher hydrophilicity. PHBV was codissolved with Ecoflex in dichloromethane at different mass ratios (PHBV/Ecoflex: 100/0, 70/30, 50/50, and 30/70) and electrospun into mats. Compared with the pure PHBV mat, the Ecoflex-containing mats showed decreased contact angles with phosphate-buffered saline (PBS), accelerated weight loss in PBS, and increased strain at break with increasing Ecoflex mass ratios. In vitro cell culture also showed significantly improved adhesion and proliferation of human bone marrow stroma cells with the introduction of Ecoflex. Blending PHBV with Ecoflex is a simple and effective method to improve the chemical, mechanical, and biological properties of PHBV simultaneously and thereby to expedite its application in tissue engineering. To our knowledge, this is the first report showing the biocompatibility of Ecoflex-containing materials with human cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Co-reporter:Hao Yu, Jian Guo, Shuqi Zhu, Yaogang Li, Qinghong Zhang, Meifang Zhu
Materials Letters 2012 Volume 74() pp:247-249
Publication Date(Web):1 May 2012
DOI:10.1016/j.matlet.2012.01.077
Alumina nanofiber is one of the most important ceramic nanomaterials, which finds many applications in mechanics, electronics, optics, etc. Polymer-alumina as-spun composite nanofibers were electrospun from a novel solution, containing water-insoluble polyacrylonitrile(PAN), nonaqueous N,N-Dimethylformamide (DMF) and aluminum 2,4-pentanedionate [Al(CH3COCHCOCH3)3], in which the mass ratio of aluminum 2,4-pentanedionate to PAN reached up to 1:1. Upon calcining the composite fibers at 1200 °C, continuous alumina nanofibers with diameters ranging from 150 to 500 nm were obtained. The alumina fibers were characterized by SEM, TEM and XRD. It was found that the surfaces of the fibers were coarsen and consisted of α-phased single-crystalline grains with sizes of approximately 10 nm.Highlights► In this paper, nonaqueous solvent DMF was selected to prepare electrospun alumina fiber and avoided gelation of aluminum 2,4-pentanedionate. ► Water-insoluble PAN with better thermal stability was used as the polymer precursor. ► After calcining, continuous α-phased alumina nanofibers with diameters ranging from 150 to 500 nm were obtained.
Co-reporter:Tian-He Dai;Kai Zhang;Mei-Fang Zhu;Yan-Mo Chen;Hans-Juergen Adler
Journal of Applied Polymer Science 2008 Volume 107( Issue 4) pp:2142-2149
Publication Date(Web):
DOI:10.1002/app.26655
Abstract
In this article, we report the preparation of a kind of novel crosslinked ultrafine fiber by electrospinning of unsaturated polyester macromonomers (UPM) and subsequent thermal crosslinking. The UPM is prepared via a two-step reaction with poly(2-methyl-1,3-propyleneadipate) diol terminated (PMPA), isophorone-diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA). Poly(3-hydroxyl-butyrate-co-3-hydroxylvalerate) (PHBV) is chosen to improve the processability of the UPM. UPM/PHBV blend ultrafine fibers are successfully electrospun with a proper mass ratio of UPM to PHBV in dichloromethane solution. The fibers are thermally crosslinked after electrospinning. Measurement results indicate that the average diameter of the fibers is about 1 μm and the crosslinked fibers have good solvent-stability and thermal-stability. This novel fiber has potential applications in filtration and protective coating. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 107:2142–2149, 2008
Co-reporter:Bin Yu, Hao Yu, Hongzhi Wang, Qinghong Zhang, Meifang Zhu
Nano Energy (April 2017) Volume 34() pp:
Publication Date(Web):April 2017
DOI:10.1016/j.nanoen.2017.02.010
•The electrospun mat-based TENG with spongy parenchyma-like structure promoted the output performance.•The spongy parenchyma-like structures made by cold-compacting increased the surface potential of triboelectic materials.•It is potential to become an energy source to directly power portable electronic equipment, like a scientific calculator.A triboelectric nanogenerator was prepared from electrospun polymer mats with a spongy parenchyma-like structure. The spongy parenchyma-like structure was imparted on the electrospun mats via cold-compacting post treatment. The optimized triboelectric nanogenerator attained a maximum electrical output, short circuit current, and load power of 695 V, 58 μA, and 3.1 W m−2, respectively. Energy harvesting from human slapping motion was used by the triboelectric nanogenerator to power an everyday scientific calculator. The mechanism of how the triboelectric power was enhanced by the spongy parenchyma-like structure is discussed, and is similar to the effect of an electret. The surface potential of the triboelectric nanogenerator based on an electrospun mat with a spongy parenchyma-like structure was higher than that based on an untreated electrospun mat. This triboelectric nanogenerator and its technology may have potential in portable electronics and flexible sensors.
