A novel flame-retardant composite material based on calcium alginate/poly (vinyl alcohol)/graphite hydrogel: thermal kinetics, combustion behavior and thermal insulation performance

Cellulose ◽  
2021 ◽  
Author(s):  
Jinru Liu ◽  
Zhicai Yu ◽  
Hualing He ◽  
Yushu Wang ◽  
Yuhang Zhao
Keyword(s):  
Composite Material ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Vinyl Alcohol ◽  
Calcium Alginate ◽  
Poly Vinyl Alcohol ◽  
Combustion Behavior ◽  
Thermal Kinetics ◽  
Insulation Performance

scholarly journals Designing New Antibacterial Wound Dressings: Development of a Dual Layer Cotton Material Coated with Poly(Vinyl Alcohol)_Chitosan Nanofibers Incorporating Agrimonia eupatoria L. Extract

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 83
Author(s):  
Cláudia Mouro ◽  
Colum P. Dunne ◽  
Isabel C. Gouveia
Keyword(s):  
Composite Material ◽  
Vinyl Alcohol ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Coating Layer ◽  
Wound Dressings ◽  
Poly Vinyl Alcohol ◽  
Microbial Invasion ◽  
Layer Composite ◽  
Medicinal Plant Extracts

Wounds display particular vulnerability to microbial invasion and infections by pathogenic bacteria. Therefore, to reduce the risk of wound infections, researchers have expended considerable energy on developing advanced therapeutic dressings, such as electrospun membranes containing antimicrobial agents. Among the most used antimicrobial agents, medicinal plant extracts demonstrate considerable potential for clinical use, due primarily to their efficacy allied to relatively low incidence of adverse side-effects. In this context, the present work aimed to develop a unique dual-layer composite material with enhanced antibacterial activity derived from a coating layer of Poly(vinyl alcohol) (PVA) and Chitosan (CS) containing Agrimonia eupatoria L. (AG). This novel material has properties that facilitate it being electrospun above a conventional cotton gauze bandage pre-treated with 2,2,6,6-tetramethylpiperidinyl-1-oxy free radical (TEMPO). The produced dual-layer composite material demonstrated features attractive in production of wound dressings, specifically, wettability, porosity, and swelling capacity. Moreover, antibacterial assays showed that AG-incorporated into PVA_CS’s coating layer could effectively inhibit Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) growth. Equally important, the cytotoxic profile of the dual-layer material in normal human dermal fibroblast (NHDF) cells demonstrated biocompatibility. In summary, these data provide initial confidence that the TEMPO-oxidized cotton/PVA_CS dressing material containing AG extract demonstrates adequate mechanical attributes for use as a wound dressing and represents a promising approach to prevention of bacterial wound contamination.

Synthesis of spherical porous cross-linked glutaraldehyde/poly(vinyl alcohol) hydrogels

2016 ◽  
Vol 36 (9) ◽  
pp. 891-898
Author(s):  
Sadao Araki ◽  
Yuko Shirakura ◽  
Harufumi Suzuki ◽  
Hideki Yamamoto
Keyword(s):  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Calcium Alginate ◽  
Chloride Solution ◽  
Calcium Chloride Solution ◽  
Inorganic Salts ◽  
Poly Vinyl Alcohol ◽  
Cross Linking ◽  
Alginate Content ◽  
Calcium Alginate Gels

Abstract Spherical glutaraldehyde cross-linked poly(vinyl alcohol) (PVA) hydrogels (G-PVA) were prepared in three steps: gelatification, cross-linking, and removal of alginate. Gelatification was carried out by dropping a solution of alginate, PVA, and glutaraldehyde into a calcium chloride solution to form calcium alginate. Calcium alginate gels were prepared at 20°C, 40°C, 60°C, and 80°C to study the effect of gelatification temperature on the formation of pores on the surface of G-PVA. The effect of the alginate content was studied. PVA and glutaraldehyde were cross-linked by immersion of the gels in a solution of H2SO4 and Na2SO4. The effect of sodium alginate and inorganic salts, such as MgSO4 and K2SO4, on the formation of pores on the surface of G-PVA was confirmed.

Entrapment of ethyl vanillin in calcium alginate and calcium alginate/poly(vinyl alcohol) beads

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Steva Levic ◽  
Verica Djordjevic ◽  
Nevenka Rajic ◽  
Milan Milivojevic ◽  
Branko Bugarski ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Calcium Alginate ◽  
Poly Vinyl Alcohol ◽  
Gel Formation ◽  
Ftir Analysis ◽  
Ethyl Vanillin ◽  
Freeze Thaw ◽  
Thermal Gravimetry ◽  
The Matrix ◽  
Cross Linker

AbstractElectrostatic extrusion was applied to the encapsulation of 3-ethoxy-4-hydroxybenzaldehyde (ethyl vanillin) in calcium alginate and calcium alginate/poly(vinyl alcohol) beads. The calcium alginate/poly(vinyl alcohol) hydrogel spheres were formed after contact with the cross-linker solution of calcium chloride, followed by the freeze-thaw method for poly(vinyl alcohol) gel formation. The entrapment of aroma in beads was investigated by FTIR and thermal analysis (thermogravimetry/differential thermal gravimetry; TGA/DTG). The mass loss in the temperature range of 150–300°C is related to degradation of the matrix and the release of ethyl vanillin. According to the DTG curve, the release of ethyl vanillin occurs at about 260°C. TGA measurements of the stored samples confirmed that formulations were stable for a period of one month. FTIR analysis provides no evidence for chemical interactions between flavour and alginate that would alter the nature of the functional groups in the flavour compound.

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