Graphene oxide and zinc oxide decorated chitosan nanocomposite biofilms for packaging applications

2020 ◽  
Vol 40 (2) ◽  
pp. 152-157 ◽  
Author(s):  
Pınar Terzioglu ◽  
Yasin Altin ◽  
Ayse Kalemtas ◽  
Ayse Celik Bedeloglu

AbstractRecently, due to sustainable development and environmental protection policies, there is increasing interest in the development of new biodegradable polymer-based multifunctional composites. Chitosan is one of the most remarkable and preferred biopolymers, which is environmentally friendly as well as renewable, biocompatible, and inexpensive. Though it has a wide range of potential applications, the major limitation of chitosan – the problem of poor mechanical performance – needs to be solved. In this work, graphene oxide was first produced and then used to manufacture a chitosan/graphene oxide/zinc oxide composite film through a casting method. The properties of the chitosan film and the chitosan/graphene oxide/zinc oxide composite film were investigated using Fourier transform infrared spectroscopy, mechanical, thermal gravimetric, and ultraviolet (UV)-visible spectroscopy analyses. The results showed that the incorporation of graphene oxide and zinc oxide into the chitosan matrix resulted in enhanced mechanical properties and thermal stability of chitosan biocomposite films. The graphene oxide- and zinc oxide-reinforced chitosan film showed 2527 MPa and 55.72 MPa of Young’s modulus and tensile strength, respectively, while neat chitosan showed only 1549 MPa and 37.91 MPa of Young’s modulus and tensile strength, respectively. Conversely, the addition of graphene oxide decreased the transmittance, notably in the UV region.

2021 ◽  
Author(s):  
Yanhong Jin ◽  
Yuanyuan Jing ◽  
Wenxin Hu ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
...  

Abstract Lignin has been used as a sustainable and eco-friendly filler in composite fibers. However, lignin aggregation occurred at high lignin content, which significantly hindered the further enhancement of fiber performance. The incorporation of graphene oxide (GO) enhanced the mechanical properties of the lignin/poly(vinyl alcohol) (PVA) fibers and affected their structure. With the GO content increasing from 0 to 0.2%, the tensile strength of 5% lignin/PVA fibers increased from 491 MPa to 631 MPa, and Young's modulus increased from 5.91 GPa to 6.61 GPa. GO reinforced 30% lignin/PVA fibers also showed the same trend. The tensile strength increased from 455 MPa to 553 MPa, and Young's modulus increased from 5.39 GPa to 7 GPa. The best mechanical performance was observed in PVA fibers containing 5% lignin and 0.2% GO, which had an average tensile strength of 631 MPa and a Young’s modulus of 6.61 GPa. The toughness values of these fibers are between 9.9-15.6 J/g, and the fibrillar and ductile fracture microstructure were observed. Structure analysis of fibers showed that GO reinforced 5% lignin/PVA fibers had higher crystallinity, and evidence of hydrogen bonding among GO, lignin, and PVA in the gel fibers was revealed. Further, water resistance and swelling behavior of composite PVA fibers were studied to further evidence the structure change of composite fibers.


2010 ◽  
Vol 654-656 ◽  
pp. 2138-2141 ◽  
Author(s):  
Xiu Song ◽  
Mitsuo Niinomi ◽  
Harumi Tsutsumi ◽  
Toshikazu Akahori ◽  
Masaaki Nakai ◽  
...  

Y2O3 was added to β-type Ti-29Nb-13Ta-4.6Zr (TNTZ) in order to achieve excellent mechanical performance and low Young’s modulus. TNTZ specimens with 0.05%–1.0% Y are all found to be composed of a β phase. Young’s moduli of TNTZ with 0.05–1.0% Y are all maintained low, and are almost the same as that of TNTZ without Y2O3. The grain size of TNTZ with 0.05%–1.0% Y is smaller than that of TNTZ without Y2O3. Moreover, Y2O3 precipitates can prevent the texture movement, and this effect becomes more obvious with an increase in the Y concentration. The tensile strength of TNTZ is successfully improved by adding Y2O3. TNTZ specimens with 0.2% and 1.0% Y exhibit good balance between the tensile strength and the elongation.


Holzforschung ◽  
2014 ◽  
Vol 68 (4) ◽  
pp. 435-446 ◽  
Author(s):  
Gunnar Engelmann ◽  
Johannes Ganster

Abstract A low-molecular lignin fraction (L) was extracted for the preparation of bio-based epoxy resins. Various compositions with the “green” 1,3-glycerol diglycidyl ether (1) and the co-component pyrogallol (2) were tested. In a first series of experiments, thermosets consisting of 1 and L, were studied with respect to variable lignin contents between 20 and 50%. The best thermoset has a tensile strength of 37 MPa and a Young’s modulus of 2.2 GPa at 40% lignin input. Secondly, lignin-free compositions of 1 and 2 were prepared. For a molar fraction of the functional groups (nOH nEpoxy-1) of 130%, the tensile strength could be enhanced to 93 MPa and the modulus reached 3.7 GPa. Finally, systems with all three components were examined. The best mechanical performance of the corresponding neat thermosets was reached at nOH nEpoxy-1 of 130%. Tensile strength decreases slightly to 86 MPa and Young’s modulus remains nearly unchanged at 3.2 GPa. Two resin compositions, L+1 and L+1+2, were tested for the preparation of unidirectional composites reinforced with man-made cellulosic fibers (50% by vol.). The bending strength was 208 MPa in combination with a bending modulus of 12.5 GPa.


The Analyst ◽  
2019 ◽  
Vol 144 (6) ◽  
pp. 1960-1967 ◽  
Author(s):  
Chao Chen ◽  
Pengcheng Zhao ◽  
Meijun Ni ◽  
Chunyan Li ◽  
Yixi Xie ◽  
...  

A temperature-induced sensing film consisting of poly(N-vinylcaprolactam) (PVCL), graphene oxide (GO) and glucose oxidase (GOD) was fabricated and used to modify a glassy carbon electrode (GCE).


2011 ◽  
Vol 695 ◽  
pp. 170-173 ◽  
Author(s):  
Voravadee Suchaiya ◽  
Duangdao Aht-Ong

This work focused on the preparation of the biocomposite films of polylactic acid (PLA) reinforced with microcrystalline cellulose (MCC) prepared from agricultural waste, banana stem fiber, and commercial microcrystalline cellulose, Avicel PH 101. Banana stem microcrystalline cellulose (BS MCC) was prepared by three steps, delignification, bleaching, and acid hydrolysis. PLA and two types of MCC were processed using twin screw extruder and fabricated into film by a compression molding. The mechanical and crystalline behaviors of the biocomopsite films were investigated as a function of type and amount of MCC. The tensile strength and Young’s modulus of PLA composites were increased when concentration of MCC increased. Particularly, banana stem (BS MCC) can enhance tensile strength and Young’s modulus of PLA composites than the commercial MCC (Avicel PH 101) because BS MCC had better dispersion in PLA matrix than Avicel PH 101. This result was confirmed by SEM image of fractured surface of PLA composites. In addition, XRD patterns of BS MCC/PLA composites exhibited higher crystalline peak than that of Avicel PH 101/PLA composites


Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 823
Author(s):  
Alexander M. Grishin

We report optical and mechanical properties of hard aluminum magnesium boride films magnetron sputtered from a stoichiometric AlMgB14 ceramic target onto Corning® 1737 Glass and Si (100) wafers. High target sputtering rf-power and sufficiently short target-to-substrate distance appeared to be critical processing conditions. Amorphous AlMgB14 films demonstrate very strong indentation size effect (ISE): exceptionally high nanohardness H = 88 GPa and elastic Young’s modulus E* = 517 GPa at 26 nm of the diamond probe penetration depth and almost constant values, respectively, of about 35 GPa and 275 GPa starting at depths of about 2–3% of films’ thickness. For comparative analysis of elastic strain to failure index  H/E*, resistance to plastic deformation ratio H3/E*2 and elastic recovery ratio We were obtained in nanoindentation tests performed in a wide range of loading forces from 0.5 to 40 mN. High authentic numerical values of H = 50 GPa and E* = 340 GPa correlate with as low as only 10% of total energy dissipating through the plastic deformations.


2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.


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