scholarly journals Bionanocellulose/Poly(Vinyl Alcohol) Composites Produced by In-Situ Method and Ex-Situ/Impregnation or Sterilization Methods

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6340
Author(s):  
Aldona Długa ◽  
Jolanta Kowalonek ◽  
Halina Kaczmarek
Keyword(s):  
Vinyl Alcohol ◽  
Gravimetric Method ◽  
Tensile Tests ◽  
Absorption Capacity ◽  
Ex Situ ◽  
Degree Of Crystallinity ◽  
Poly Vinyl Alcohol ◽  
Angle Measurements ◽  
In Situ Method

The purpose of the work was to obtain composites based on bionanocellulose (BNC) and poly(vinyl alcohol) (PVA) for specific biomedical and cosmetic applications and to determine how the method and conditions of their preparation affect their utility properties. Three different ways of manufacturing these composites (in-situ method and ex-situ methods combined with sterilization or impregnation) were presented. The structure and morphology of BNC/PVA composites were studied by ATR-FTIR spectroscopy and scanning microscopy (SEM, AFM). Surface properties were tested by contact angle measurements. The degree of crystallinity of the BNC fibrils was determined by means of the XRD method. The mechanical properties of the BNC/PVA films were examined using tensile tests and via the determination of their bursting strength. The water uptake of the obtained materials was determined through the gravimetric method. The results showed that PVA added to the nutrient medium caused an increase in biosynthesis yield. Moreover, an increase in base weight was observed in composites of all types due to the presence of PVA. The ex-situ composites revealed excellent water absorption capacity. The in-situ composites appeared to be the most durable and elastic materials.

scholarly journals In situ and ex situ synthesis of poly(vinyl alcohol)–Fe3O4 nanocomposite flame retardants

Particuology ◽  
2016 ◽  
Vol 26 ◽  
pp. 87-94 ◽  
Author(s):  
Davood Ghanbari ◽  
Masoud Salavati-Niasari ◽  
Majid Ghasemi-Kooch
Keyword(s):  
Vinyl Alcohol ◽  
Flame Retardants ◽  
Ex Situ ◽  
Poly Vinyl Alcohol

scholarly journals Development and Characterization of a Poly (Vinyl Alcohol)/Graphene Oxide Composite Hydrogel as An Artificial Cartilage Material

2018 ◽  
Vol 8 (11) ◽  
pp. 2272 ◽  
Author(s):  
Yibo Zhao ◽  
Wataru Terai ◽  
Yuko Hoshijima ◽  
Kazuma Gotoh ◽  
Koji Matsuura ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Vinyl Alcohol ◽  
Cell Attachment ◽  
Tensile Tests ◽  
Composite Hydrogel ◽  
Poly Vinyl Alcohol ◽  
Sem Images ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Surface Contact Angle

Poly (vinyl alcohol) hydrogel (PVA-H) is expected to be a suitable artificial articular cartilage material because of its high biocompatibility. However, it is difficult to affix to the surface of a living joint because it is bioinert and its mechanical strength needs to be improved. In this study, graphene oxide (GO) subjected to two oxidation rounds was used to form a nanocomposite material and the composite hydrogel PVA-GO-H was prepared by low-temperature crystallization. Scanning electron microscope (SEM) images showed that the addition of GO can increase roughness of the hydrogel surface. Contact angle measurements showed that the surface of PVA-GO-H exhibited hydrophobicity that increased with GO concentration and not with that of PVA-H, indicating that the hydrophilic parts of PVA and GO form hydrogen bonds and the hydrophobic part of GO was exposed on the surface. Tensile tests demonstrated that Young’s modulus was enhanced on the addition of GO. Osteoblast cells showed more affinity for PVA-GO-H than PVA-H, which much more cells adhere to than to PVA-GO-H after a certain period of culturing, suggesting GO can improve the cell attachment of PVA-H. Further studies on the influence of the oxidation time of GO are still required.

scholarly journals Graphene Based Poly(Vinyl Alcohol) Nanocomposites Prepared by In Situ Green Reduction of Graphene Oxide by Ascorbic Acid: Influence of Graphene Content and Glycerol Plasticizer on Properties

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1013 ◽  
Author(s):  
Mónica Cobos ◽  
M. Fernández ◽  
M. Fernández
Keyword(s):  
Ascorbic Acid ◽  
Graphene Oxide ◽  
Water Absorption ◽  
Vinyl Alcohol ◽  
Nanocomposite Films ◽  
Ex Situ ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
Water Barrier

The enhanced properties of polymer nanocomposites as compared with pure polymers are only achieved in the presence of well-dispersed nanofillers and strong interfacial adhesion. In this study, we report the preparation of nanocomposite films based on poly(vinyl alcohol) (PVA) filled with well dispersed graphene sheets (GS) by in situ reduction of graphene oxide (GO) dispersed in PVA solution using ascorbic acid (L-AA) as environmentally friendly reductant. The combined effect of GS content and glycerol as plasticizer on the structure, thermal, mechanical, water absorption, and water barrier properties of PVA/GS nanocomposite films is studied for the first time. Higher glass transition temperature, lower crystallinity, melting, and crystallization temperature, higher mechanical properties, and remarkable improvement in the thermal stability compared to neat PVA are obtained as a result of strong interfacial interactions between GS and PVA by hydrogen bonding. PVA/GS composite film prepared by ex situ process is more brittle than its in situ prepared counterpart. The presence of GS improves the water barrier and water resistance properties of nanocomposite films by decreasing water vapor permeability and water absorption of PVA. This work demonstrates that the tailoring of PVA/GS nanocomposite properties is enabled by controlling GS and glycerol content. The new developed materials, particularly those containing plasticizer, could be potential carriers for transdermal drug delivery.

scholarly journals In Situ Preparation and Properties of Poly(vinyl alcohol)/Carboxymethyl Chitosan/Cyanidin Hydrogel Films

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Xiaojuan Zhang ◽  
Wenbin Cai ◽  
Lingyun Hao ◽  
Wei Zhang
Keyword(s):  
Vinyl Alcohol ◽  
Encapsulation Efficiency ◽  
Umbilical Vein ◽  
Antibacterial Activities ◽  
Carboxymethyl Chitosan ◽  
Poly Vinyl Alcohol ◽  
In Situ Preparation ◽  
Umbilical Vein Endothelial Cells ◽  
Hydrogel Films

This study synthesized poly(vinyl alcohol)/carboxymethyl chitosan/cyanidin (PVA/CMCS/CY) hydrogel films. First, PVA and CMCS were used to synthesize hydrogel films by ultraviolet irradiation. Meanwhile, CY was in situ combined into the hydrogel films through the electrostatic attraction between CMCS and CY. Next, the products were analyzed using Fourier-transform infrared spectroscopy, scanning electron microscopy, contact angle test, swelling analysis, and mechanical property test. The results revealed that compared with PVA/CMCS hydrogel films, the PVA/CMCS/CY hydrogel films had an interporous structure and good swelling and mechanical properties. Moreover, the drug release experiments demonstrated that the PVA/CMCS/CY hydrogel films had a CY encapsulation efficiency of 33.5% with a sustained CY release of up to 60 h. Furthermore, the examined antibacterial activities against Staphylococcus aureus and Escherichia coli showed that the porous PVA/CMCS/CY hydrogel films exhibited a certain inhibition. Cell viability experiments demonstrated that the PVA/CMCS/CY films displayed no obvious cytotoxicity to human umbilical vein endothelial cells.

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