Graphene/polyurethane composites: fabrication and evaluation of electrical conductivity, mechanical properties and cell viability

RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 98762-98772 ◽  
Author(s):  
Gagan Kaur ◽  
Raju Adhikari ◽  
Peter Cass ◽  
Mark Bown ◽  
Margaret D. M. Evans ◽  
...  

Conductive composites of graphene and a siloxane polyurethane (Elast-Eon™) were prepared to explore their potential for use in biomedical applications.

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1774 ◽  
Author(s):  
Haoran Zhang ◽  
Juntao Zhao ◽  
Tieling Xing ◽  
Shenzhou Lu ◽  
Guoqiang Chen

Silk fibroin (SF) is a natural material with good biocompatibility and excellent mechanical properties, which are complementary to graphene with ultrahigh electrical conductivity. In this study, to maximally combine graphene and silk fibroin, a well-dispersed silk fibroin/graphene suspension was successfully prepared in a simple and effective way. Then we prepared a flexible conductive SF/graphene film with a minimum resistance of 72.1 ± 4.7 Ω/sq by the casting method. It was found that the electrical conductivity of the SF/graphene film was related to the water content of the film, and the variation was more than 200 times. Therefore, it will play an important role in the field of humidity sensors. It also has excellent mechanical properties in both wet and dry states. These unique features make this material a promising future in the fields of biomedical applications, wearable sensors, and implantable internal sensors.


2013 ◽  
Vol 750-752 ◽  
pp. 119-122 ◽  
Author(s):  
Xiao Ya Wang ◽  
Zhi Dong Xia ◽  
Zhe Li

This study was carried out to discuss the influence of curing temperature on the performance of conductive composites filled with nickel-coated graphite (NCG). The electrical conductivity, crosslink density, mechanical properties and tensile fracture morphology have been investigated. The results indicated that curing temperature had great impact on the electrical conductivity and mechanical properties. Voluem resistivity decreased from 43.1 to 0.08 ohm-cm at 125°C-205°C, and the reason was discussed in light of formation and break of the conductive network in the composites. The stability of SR-NCG cured at 165°C-205°C were also better than those cured at other curing temperature. Besides, tensile strength increased from 2.41 to 7.19Mpa at 125°C-225°C, elongation at break have a 56% increase, and Shore A hardness also incresed from 74 to 82.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 111 ◽  
Author(s):  
Jin-Oh Jeong ◽  
Jong-Seok Park ◽  
Young-Ah Kim ◽  
Su-Jin Yang ◽  
Sung-In Jeong ◽  
...  

Conducting polymer (CP)-based hydrogels exhibit the behaviors of bending or contraction/relaxation due to electrical stimulation. They are similar in some ways to biological organs and have advantages regarding manipulation and miniaturization. Thus, these hydrogels have attracted considerable interest for biomedical applications. In this study, we prepared PPy/PVP hydrogel with different concentrations and content through polymerization and cross-linking induced by gamma-ray irradiation at 25 kGy to optimize the mechanical properties of the resulting PPy/PVP hydrogel. Optimization of the PPy/PVP hydrogel was confirmed by characterization using scanning electron microscopy, gel fraction, swelling ratio, and Fourier transform infrared spectroscopy. In addition, we assessed live-cell viability using live/dead assay and CCK-8 assay, and found good cell viability regardless of the concentration and content of Py/pTS. The conductivity of PPy/PVP hydrogel was at least 13 mS/cm. The mechanical properties of PPy/PVP hydrogel are important factors in their application for biomaterials. It was found that 0.15PPy/PVP20 (51.96 ± 6.12 kPa) exhibited better compressive strength than the other samples for use in CP-based hydrogels. Therefore, it was concluded that gamma rays can be used to optimize PPy/PVP hydrogel and that biomedical applications of CP-based hydrogels will be possible.


2014 ◽  
Vol 1004-1005 ◽  
pp. 517-520
Author(s):  
Bao Zhong Han ◽  
Cheng Cheng Zhang ◽  
Bang An ◽  
Chun Yang Li ◽  
Chang Ming Li

In order to select effective carbon black (CB) and matrix resin for fabricating semi-conductive shielding materials of XLPE insulated high voltage cable, the crosslinkable composites were prepared by melt blending different types of CB with three types of copolymer resin, and the crosslinking samples were compressed. The electrical conductivity, mechanical properties, thermal elongation properties and rheological properties of the crosslinkable semi-conductive composites were measured. The research results indicated that compared to EVA-based and EEA1-based composites, the EEA2-based composites have the lowest volume resistivity and the best rheological properties, and the CB content has less effect on their mechanical properties. The properties of the composites with CB1 were superior to that of the composites with CB2. The composites prepared with CB1 and EEA2 present the best overall properties. These composites are expected to be used in the manufacture of semi-conductive shielding layer for high voltage cable.


2008 ◽  
Vol 49 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Toshikazu Akahori ◽  
Mitsuo Niinomi ◽  
Masaaki Nakai ◽  
Hideki Nishimura ◽  
Yukiko Takei ◽  
...  

2021 ◽  
Author(s):  
Asma M. Alturki ◽  
Dalia E. Abulyazied ◽  
Mohammed Taha ◽  
H. M. Abomostafa ◽  
Rasha A. Youness

Abstract The aim of this work is to prepare nanocomposites with excellent bioactivity and appropriate mechanical properties. In this regard, the nanocomposites, with different contents of borosilicate glass (BG) and carbonated hydroxyapatite (CHA), were mixed and milled using a high-energy ball mill. Then, these milled powders were subjected to sintering at 750 ºC. In order to examine their phase composition, molecular structure and microstructure, X-ray diffraction (XRD) technique, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), respectively were used. Moreover, the DC electrical conductivity, and physical and mechanical properties of the prepared nanocomposites were also measured. In addition, the in vitro bioactivity of the sintered samples was evaluated using XRD and SEM. Unexpectedly; the results indicated that the successive increase in BG contents promoted the partial decomposition of CHA molecules at this lower sintering temperature. Also, it was responsible for the enhanced bioactivity behavior along with giving CHA better mechanical properties. However, the electrical conductivity of the examined samples exhibited an opposite trend where it decreased significantly with increasing BG content. According to the results obtained, the prepared samples are suitable for use in various biomedical applications.


1990 ◽  
Vol 63 (5) ◽  
pp. 275-283 ◽  
Author(s):  
Mutsuhisa FURUKAWA ◽  
Kenji SUSUKIDA ◽  
Tetsuo YOKOYAMA

2005 ◽  
Vol 106 ◽  
pp. 153-160 ◽  
Author(s):  
Kim Vanmeensel ◽  
K.Y. Sastry ◽  
J. Hennicke ◽  
Guy Anné ◽  
Dongtao Jiang ◽  
...  

Future materials for wear resistant components require a combination of excellent mechanical properties such as hardness and toughness, short processing times and good electrical conductivity to facilitate shaping by electro discharge machining (EDM). In this work, the hardness and fracture toughness of t-ZrO2 based electro conductive composites was optimised, while short processing times below 20 minutes using spark plasma sintering were sufficient to obtain near fully dense materials. The influence of powder processing technique using TiC0.5N0.5 as the starting powder and yttria as a stabiliser on the mechanical properties of ZrO2-TiC0.5N0.5-Al2O3 based composites was investigated. Fully dense Y-TZP based composites possessed an excellent toughness of 9.2 MPa.m1/2 and an increased Vickers hardness of 1397 kg/mm².


2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.


2020 ◽  
Vol 1010 ◽  
pp. 638-644
Author(s):  
Mohd Pisal Mohd Hanif ◽  
Abd Jalil Jalilah ◽  
Mohd Fadzil Hanim Anisah ◽  
Arumugam Tilagavathy

Biopolymer-based conductive polymer composites (CPCs) would open up various possibilities in biomedical applications owing to ease of processing, renewable resource and environmentally friendly. However, low mechanical properties are a major issue for their applications. In this study, the investigated the conductivity of chitosan/ PEO blend films filled with carbonized wood fiber (CWF) prepared by solution casting. The effect of CWF was also investigated on tensile properties and their morphological surfaces. The tensile results from different ratios of chitosan/PEO blend films without CWF show that the tensile strength and modulus increased with the increase of chitosan content and chitosan/PEO blend film with 70/30 ratio exhibited the best combination of tensile strength and flexibility. However, a reduction of tensile strength was observed when CWF amount was increased while the modulus of the tensile shows an increment. The film also exhibited higher electrical conductivity as compared to low chitosan ratio. The addition of CWF greatly enhanced the conductivity three-fold from 10-10 to 10-6 S/cm. The electrical conductivity continued to increase with the increase of CWF up to 30wt%. The surface morphology by Scanning Electron Microscopy (SEM) exhibits the absence of phase separation for the blends indicating good miscibility between the PEO and chitosan. Incorporation of CWF into the blend films at 5wt% showed agglomeration. However, the increase of CWF created larger agglomerations that formed conductive pathways resulting in improved conductivity. FTIR analysis suggested that intermolecular interactions occurred between chitosan and PEO while CWF interacts more with the protons of PEO.


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