Novel CH3NH3PbI3/polyimide composites with enhanced film-forming and electrical conductive properties

2017 ◽  
Vol 30 (7) ◽  
pp. 847-855
Author(s):  
Qing Li ◽  
Jing Li ◽  
Shulai Zhang ◽  
Changfeng Yi ◽  
Zushun Xu

A series of CH3NH3PbI3/polyimide (PI) composite films were successfully fabricated using simple solution mixing. CH3NH3PbI3 particles were evenly dispersed into PI substrate, which could be seen from scanning electron microscopy images. Tensile test showed that the tensile strength of CH3NH3PbI3/PI composite film (5 wt%) was improved to the maximum (102.2 MPa), 127% higher than pure PI; and the elongation at break was remarkably stretched to 13% for CH3NH3PbI3/PI composite film (3 wt%), 171% greater than pure PI. Moreover, the thermal performance was enhanced to the optimum with the addition of 5 wt% CH3NH3PbI3. Ultraviolet–visible absorption curves revealed that the colors of CH3NH3PbI3/PI composite films were darkened and the red shift increased with the increasing content of CH3NH3PbI3. Furthermore, the CH3NH3PbI3/PI composite films exhibited increased dielectric constant with the maximum value of 13.8, compared with pure PI (3.6). These composite films may be promising to be used as dielectric materials in electronic industry.

2013 ◽  
Vol 750-752 ◽  
pp. 1582-1585
Author(s):  
Chun Hong Zhang ◽  
Nan Chang ◽  
Chen Li ◽  
Xin Hua Li

Zein was added into wheat gluten (WG) to prepare zein composite films (ZCF) in order to improve the properties of films. The film-forming ability, properties, surface microstructure and infrared spectrum of WG films and ZCF were investigated. The results show that the viscosity of film-forming solutions decrease, and uniformity become worse slightly, after zein added. ZCF are yellow, with metal luster, whose toughness and water retention increase. Compared to the control, the ZCF tensile strength (TS), elongation at break (EB) and resistance of oxygen are increased by 33.2%, 17.2% and 11.25%, and water vapor permeability (WVP) and transparency are decreased by 26.0% and 75.4% respectively. ZCF have better antibacterial properties than WG films. The inhibition effect on escherichia coli and staphylococcus aureus are increased by 36.36% and 32.89% respectively. Hydrogen bond interaction of ZCF become weak, and the surface of ZCF become smooth and evenly.


2011 ◽  
Vol 399-401 ◽  
pp. 381-384
Author(s):  
Chun Guang Li ◽  
Bin Guo Zheng ◽  
Wei Gong Peng ◽  
Wei Tian ◽  
Rui Zhang

The biodegradable composite films were prepared from bagasse microcrystalline cellulose as filler and poly(vinyl alcohol)(PVA) as polymeric matrix. The crystallinity, the tensile properties and the thermal properties of the composites were tested. Bagasse microcrystalline cellulose was distributed in PVA films as the crystalline state. The results show that the tensile properties and thermal properties were improved with the addition of bagasse microcrystalline cellulose. When bagasse microcrystalline cellulose mass fraction was 5%, both temperature of initial decomposition and maximum weight loss rate of composite film were raised by 11.71°C and 36.86°C, and the tensile strength increased by 17.88%, and the elongation at break increased by 36.62% compared to those of pure PVA.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 84
Author(s):  
Sijun Ma ◽  
Yuanrong Zheng ◽  
Ran Zhou ◽  
Ming Ma

Four kinds of edible composite films based on chitosan combined with additional substances (konjac glucomannan, cassava starch, maltodextrin and gelatin) and the addition of lysozyme were prepared and used as packaging materials for Mongolian cheese. The prepared composite films were evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. The physicochemical properties of all chitosan composite films, including thickness, viscosity, opacity, color, moisture content, water vapor permeability, tensile strength and elongation at break, were measured. The results show that Konjac glucomannan–chitosan composite film presented the strongest mechanical property and highest transparency. The cassava starch–chitosan composite film presented the highest water barrier property. The study on the storage characteristics of Mongolian cheese was evaluated at 4 °C. The results show that the cheese packaging by cassava starch–chitosan composite film presented better treatment performance in maintaining the quality, reducing weight loss and delayering microbial growth.


2016 ◽  
Vol 12 (8) ◽  
pp. 773-781 ◽  
Author(s):  
Kingsley Masamba ◽  
Yue Li ◽  
Hafiz Rizwan Sharif ◽  
Jianguo Ma ◽  
Fang Zhong

Abstract The effect of gallic acid treatment on mechanical and water barrier properties in zein and zein–corn starch composite films was investigated. Four concentrations of corn starch (5 %, 10 %, 15 %, 20 %) were used in composite films making a final solid concentration of 6 % (w/v) in the film forming solution. One composite film containing 10 % corn starch was also prepared in absence of gallic acid for comparison purpose. Gallic acid treatment improved tensile strength (TS) and water vapor permeability (WVP) while solubility was increased in control zein films. On the other hand, gallic acid treatment significantly (p < 0.05) reduced TS and increased WVP in zein–corn starch composite films. Interestingly, mechanical and water barrier properties of composite films prepared in absence of gallic acid were comparatively better than gallic acid treated composite films. These findings provided useful insights in how each individual hydrocolloid in the composite film was differently affected by gallic acid treatment.


2020 ◽  
Vol 850 ◽  
pp. 87-93
Author(s):  
Thi Luong Nguyen ◽  
Hoc Thang Nguyen ◽  
Van Khoi Nguyen ◽  
Thi Thu Ha Pham ◽  
Thi Hong Thuy Le ◽  
...  

This article is aimed at evaluating newly synthesized HPMC/BW composite films, applied for preservation of seedless lime fruit. Factors influenced to formation of the films as well as characteristics of HPMC/BW edible composite films were researched and analyzed based on experimental results and previous studies. The HPMC/BW edible composite films were created based on the components included HPMC (5% w/v), Glycerol plasticizer (Gly-2% v/v), BW (5% w/v); Oleic Acid emulsifier (OA-1% v/v). Characteristics of the composite film were evaluated via the analytical techniques known as Sensory, Tensile Strength (TS), Elongation at Break (EB), ThermoGravimetric Analyzer (TGA), Scanning Electron Microscope (SEM), Fourier Transform InfraRed (FTIR). HPMC/BW composite films applied in preserving seedless limes. Evaluations of preservation processes were based on effects of characteristics such as Sensory evaluation, Respiratory intensity, Weight loss, Vitamin C content, Total acid of before and after fruits preservation.


2014 ◽  
Vol 941-944 ◽  
pp. 1133-1140 ◽  
Author(s):  
Shuai Peng ◽  
Li Hong Niu ◽  
Ke Qiang Lai ◽  
Yi Qun Huang

The present study was to investigate the film forming properties of tilapia skin gelatin as affected by the addition of 2%, 5% Arabic gum or pectin (g/g gelatin), as well as 1%, 2% glutaraldehyde (GTA) (g/g gelatin) in an attempt to improve gelatin film properties. Tensile strength (TS) and transparency of gelatin film were improved 36.6% and 30.3% by the addition of Arabic gum, respectively, while the water vapor permeability (WVP) was not affected. The addition of pectin had less effect on the film tensile strength and transparency, but led to 41.7% of increase in WVP. Tensile strength and WVP of gelatin-arabic gum composite film cross-linked with 2% GTA were better than those of 1% GTA cross-linked composite film, though the extensibility and transparency were slightly weak. The FTIR spectra of gelatin films showed that both Arabic gum and pectin formed cross-linkages with gelatin protein molecules, while GTA facilitated the formation of intermolecular bonds, resulting in more stable films.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3777
Author(s):  
Han Wu ◽  
Jing Li ◽  
Yule Wu ◽  
Hui Gao ◽  
Ying Guan

For the high-value utilization of hemicellulose-based composite films, the poor film-forming and mechanical properties of hemicellulose-based composite films must be surmounted crucially. Based on this, hemicellulose-based organic-inorganic composite films with good mechanical properties were prepared from quaternized hemicelluloses (QH), bentonite, and polyethyleneimine (PEI). The QH/PEI/bentonite composite films were prepared by vacuum filtration, and the properties of the composite film were investigated. The results showed that the QH was inserted into bentonite nanosheets through hydrogen bonding and electrostatic interactions. PEI was cross-linked with hemicellulose by hydroxyl groups, electrostatically attracted by the bentonite flake layers. The mechanical properties of the composite films were significantly increased by the incorporation of PEI. When the PEI content was 20%, the tensile stress of the composite film was increased by 155.18%, and the maximum tensile stress was reached 80.52 MPa. The composite films had strong UV absorption ability with the transmittance was almost 0 in the UV region from 200 to 300 nm. The thermal property of composite film was also improved, and the residual mass increased by three times compared to QH. These results provide a theoretical basis for the use of hemicellulose-based composite films in packaging applications.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4370
Author(s):  
Ling Pan ◽  
Peng Li ◽  
Yubo Tao

As a natural macromolecule-based biomaterial, fish gelatin is used in medical materials for its low pathogen infection risk. However, because of poor mechanical properties, its application has been limited. In this study, microcrystalline cellulose-reinforced fish gelatin (FG/MCC) composite films were prepared with a biological cross-linking agent (genipin) under ultrasonic treatment. SEM micrographs showed that the smooth microstructure of FG film became increasingly disordered with the addition of MCC. The infrared spectrum analysis (FTIR) demonstrated the existence of hydrogen bond interaction between MCC and FG. Compared with the pure FG film, the tensile strength (TS) and modulus of elasticity (MOE) of composite films with MCC were improved, and the elongation at break (EAB) and swelling ratios (SR) were decreased. Ultrasonic treatment could further improve TS, MOE, and SR. When the composite film was prepared with 15% MCC and treated with ultrasound, the TS and MOE increased by 115% and 227%, respectively, while the EAB decreased by 35% and the SR decreased by 4% in comparison with pure FG films. Thermo-gravimetric analysis (TGA) showed that the FG/MCC composite films were stable below 100 °C. The above results indicate that the FG/MCC films have optimistic application prospects in the biomedical field.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Lizhu Liu ◽  
Ling Weng ◽  
Yuxia Song ◽  
Lin Gao ◽  
Qingquan Lei

PI/nano-Al2O3hybrid films were prepared by ultrasonic-mechanical method. Before addition, nano-Al2O3particles were firstly modified with different coupling agents. The micromorphology, thermal stability, mechanical properties, and electric breakdown strength of hybrid films were characterized and investigated. Results indicated that nano-Al2O3particles were homogeneously dispersed in the PI matrix by the addition of coupling agents. The thermal stability and mechanical properties of PI/nano-Al2O3composite films with KH550 were the best. The tensile strength and elongation at break of PI composite film were 119.1 MPa and 19.1%, which were 14.2% and 78.5% higher than unmodified PI composite film, respectively.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2544
Author(s):  
Cenkai Xu ◽  
Chengmei Wei ◽  
Qihan Li ◽  
Zihan Li ◽  
Zongxi Zhang ◽  
...  

Dielectric materials with excellent thermally conductive and mechanical properties can enable disruptive performance enhancement in the areas of advanced electronics and high-power devices. However, simultaneously achieving high thermal conductivity and mechanical strength for a single material remains a challenge. Herein, we report a new strategy for preparing mechanically strong and thermally conductive composite films by combining aramid nanofibers (ANFs) with graphene oxide (GO) and edge-hydroxylated boron nitride nanosheet (BNNS-OH) via a vacuum-assisted filtration and hot-pressing technique. The obtained ANF/GO/BNNS film exhibits an ultrahigh in-plane thermal conductivity of 33.4 Wm−1K−1 at the loading of 10 wt.% GO and 50 wt.% BNNS-OH, which is 2080% higher than that of pure ANF film. The exceptional thermal conductivity results from the biomimetic nacreous “brick-and-mortar” layered structure of the composite film, in which favorable contacting and overlapping between the BNNS-OH and GO is generated, resulting in tightly packed thermal conduction networks. In addition, an outstanding tensile strength of 93.3 MPa is achieved for the composite film, owing to the special biomimetic nacreous structure as well as the strong π−π interactions and extensive hydrogen bonding between the GO and ANFs framework. Meanwhile, the obtained composite film displays excellent thermostability (Td = 555 °C, Tg > 400 °C) and electrical insulation (4.2 × 1014 Ω·cm). We believe that these findings shed some light on the design and fabrication of multifunctional materials for thermal management applications.


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