scholarly journals Co-exfoliation and fabrication of graphene based microfibrillated cellulose composites – mechanical and thermal stability and functional conductive properties

Nanoscale ◽  
2018 ◽  
Vol 10 (20) ◽  
pp. 9569-9582 ◽  
Author(s):  
Josphat Phiri ◽  
Leena-Sisko Johansson ◽  
Patrick Gane ◽  
Thad C. Maloney

The excellent functional properties of graphene and micro-nanofibrillated cellulose (MNFC) offer plenty of possibilities for wide ranging applications in combination as a composite material.

2017 ◽  
Vol 37 (9) ◽  
pp. 921-931 ◽  
Author(s):  
Bayram Poyraz ◽  
Ayhan Tozluoğlu ◽  
Zeki Candan ◽  
Ahmet Demir

Abstract This study reports on the effect of organic polyvinyl alcohol (PVA) and silica matrix on the properties of cellulose-based nanocomposites. Nanofibrillated cellulose was isolated from kraft pulp and treated with Pulpzyme HC 2500 enzyme prior to high-pressure homogenization in order to lower energy consumption. Three nanocomposite films were fabricated via the casting process: nanofibrillated cellulose, nanocellulose-PVA (NC-PVA) and nanocellulose-silica (NC-Si). Chemical characterization and crystallization were determined with FTIR. Thermal stability was investigated with thermogravimetric analysis. Morphological alterations were monitored with scanning electron microscopy. A universal testing machine and dynamic mechanical thermal analysis were used for determination of Young’s and storage moduli. The real and imaginary parts of permittivity and electric modulus were evaluated using an impedance analyzer. Considerable alterations were seen under FTIR. Thermal stability was lower in NC-Si than in NC-PVA due to lower crystallinity. Higher Young’s modulus and storage moduli were observed in NC-PVA than in NC-Si. NC-PVA exhibited a singular relaxation process, while a double relaxation process was seen in NC-Si. Consequently, the nanocomposite film prepared from the organic matrix (NC-PVA) had a mechanical advantage for industrial applications. However, neat NC composite revealed the highest storage modulus and thermal stability.


2015 ◽  
Vol 16 (4) ◽  
pp. 700-705
Author(s):  
I.F. Myronyuk ◽  
V.I. Mandzyuk ◽  
V.M. Sachko ◽  
Yu.O. Kyluk

The article explores the structure, morphology and conductive properties of composite material SiO2 – C using XRD, SAXS, low-temperature nitrogen adsorption, and impedance spectroscopy methods. It is set that SiO2 – C composite obtained by thermolytic decomposition of D-lactose, previously chemisorbed on fumed silica nanoparticles surface, has an open porous structure, in which mesopores of 6-12 nm in size are dominate. At weight ratio SiO2/C = 5/1 nanocrystallites of carbon phase in form of lamellar sheets of 0,4 × 0,4 × 5,0 nm3 in size contact with entire silica surface that results in composite material conductivity is 49 Оhm-1·m-1.


RSC Advances ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 3619-3625 ◽  
Author(s):  
Shuang Yang ◽  
Qiuxia Xie ◽  
Xiuyu Liu ◽  
Min Wu ◽  
Shuangfei Wang ◽  
...  

Bleached softwood pulp was used to prepare nanofibrillated cellulose (NFC) by mechanical grinding and a high-pressure homogenization process.


2020 ◽  
Vol 850 ◽  
pp. 107-111
Author(s):  
Laimonis Mālers ◽  
Agnija Cirvele

Functional properties of composite material based on mechanically grinded scrap tires with different particle size of fractioned crumb and polyurethane type polymer binder were investigated to estimate influence of rubber particles size and content on composite material properties (Shore C hardness, compressive stress at 10 % deformation, tensile strength, elastic modulus and elongation at break, apparent density). Optimization possibilities of composite material consisting of rubber particles with different sizes or fractions were investigated. The obtained results show that variation of composition of the composite material by changing size of rubber granulate have definite influence on selected properties of the material. Purposeful selection and mutual combination of rubber particles size included in material can ensure desirable and predictable mechanical properties of composite material.


Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1149
Author(s):  
Naresh Shahi ◽  
Gautam Joshi ◽  
Byungjin Min

In this study, agricultural residue from black oat, a cover crop usually grown to improve soil nutrients between the periods of regular crop production, was used as a source of cellulose fibers. Concentrations of 1, 3, and 5 wt. % of regenerated cellulose (RC) fibers blended in poly(vinyl alcohol) (PVA) solution were used to prepare the reinforced composite films (CFs) by the solvent cast method. Compared to neat PVA film (control), the effects of RC addition on functional properties of CFs, such as water absorption, transparency, thermal stability, and mechanical property were investigated. All CFs with different RC concentrations exhibited improved mechanical property and thermal stability while the swelling property was decreased, and no significant changes were observed in the film transparency as compared with the control film. Among the CFs, films with 3% RC significantly decreased water vapor transmission rate, swelling, and soluble fraction (p < 0.05). In addition, Young’s modulus and tensile strength were increased by 40 MPa and 3 MPa, respectively, while elongation at break was decreased by 4%, compared to the control film. The results indicate that RC from black oat might be feasible as potential bio fillers to improve film properties in a bio-based composite matrix.


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