scholarly journals Physically Crosslinked Poly (Vinyl Alcohol)/Kappa-Carrageenan Hydrogels: Structure and Applications

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 560 ◽  
Author(s):  
Catalin Croitoru ◽  
Mihai Alin Pop ◽  
Tibor Bedo ◽  
Mihaela Cosnita ◽  
Ionut Claudiu Roata ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Diffusion Coefficients ◽  
Vinyl Alcohol ◽  
Weight Ratio ◽  
Poly Vinyl Alcohol ◽  
Distilled Water ◽  
Cationic Dye ◽  
Structure Morphology ◽  
Physically Crosslinked ◽  
Kappa Carrageenan

This paper discusses the structure morphology and the thermal and swelling behavior of physically crosslinked hydrogels, obtained from applying four successive freezing–thawing cycles to poly (vinyl alcohol) blended with various amounts of κ-carrageenan. The addition of carrageenan in a weight ratio of 0.5 determines a twofold increase in the swelling degree and the early diffusion coefficients of the hydrogels when immersed in distilled water, due to a decrease in the crystallinity of the polymer matrix. The diffusion of water into the polymer matrix could be considered as a relaxation-controlled transport (anomalous diffusion). The presence of the sulfate groups determines an increased affinity of the hydrogels towards crystal violet cationic dye. A maximum physisorption capacity of up to 121.4 mg/g for this dye was attained at equilibrium.

scholarly journals Diffusion and Controlled Release in Physically Crosslinked Poly (Vinyl Alcohol)/Iota-Carrageenan Hydrogel Blends

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1544 ◽  
Author(s):  
Catalin Croitoru ◽  
Ionut Claudiu Roata ◽  
Alexandru Pascu ◽  
Elena Manuela Stanciu
Keyword(s):  
Vinyl Alcohol ◽  
Weight Ratio ◽  
Mesh Size ◽  
Strong Interactions ◽  
Poly Vinyl Alcohol ◽  
Release Rates ◽  
Antibiotic Drugs ◽  
Swelling Mechanism ◽  
Physically Crosslinked ◽  
Crystalline Domains

This paper reports the obtaining of poly (vinyl alcohol) and ι-carrageenan blend hydrogels by physical crosslinking (consecutive freeze–thaw cycles). The two polymers were completely miscible in the weight ratio interval used in this study, as determined by solution viscometry data. Strong interactions through hydrogen bonding and forming of mixed interpolymer crystalline domains were observed, which are responsible for the formation of stable drug release-tunable matrices. The release profiles of three model antibiotic drugs (amoxicillin, tetracycline hydrochloride, and gentamicin sulfate) were assessed in a pH interval between 3 and 7.3. They were found to be strongly dependent on the drug chemistry, mesh size of the hydrogels, swelling mechanism, and pH of the release medium. A decrease of up to 40% in the release rates and up to 10% in the diffusion coefficients of the model drugs was registered with the increase in ι-carrageenan content.

scholarly journals A facile method for synthesizing free-shaped and tough double network hydrogels using physically crosslinked poly(vinyl alcohol) as an internal mold

2010 ◽  
Vol 1 (5) ◽  
pp. 693 ◽  
Author(s):  
Tasuku Nakajima ◽  
Naoyuki Takedomi ◽  
Takayuki Kurokawa ◽  
Hidemitsu Furukawa ◽  
Jian Ping Gong
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Internal Mold ◽  
Double Network ◽  
Physically Crosslinked

Synthesis of Poly(vinyl alcohol)/Chitosan/Titanium Oxide Beads

2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Syazwan Liyana Sulaiman ◽  
Zawati Harun ◽  
Sufizar Ahmad ◽  
Hariati Taib
Keyword(s):  
Wastewater Treatment ◽  
Titanium Oxide ◽  
Alkaline Solution ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Distilled Water ◽  
Swelling Properties ◽  
Promising Alternative ◽  
Porous Beads ◽  
Mean Time

The application of photocatalytic beads in wastewater treatment application has gained attention of many researchers. In this study, the synthesised poly(vinyl alcohol)/chitosan/Titanium oxide (PVA/CS/TiO2) beads has been considered as a promising alternative to conventional means of wastewater treatment. The present study has successfully synthesised PVA/CS/TiO2 beads through simple dropwise method in which varied concentration of CS from 1.0 g to 2.5 g. Morphological analysis of the synthesised PVA/CS/TiO2 beads investigated by the FE-SEM technique revealed that porous beads were obtained regardless of the varied CS concentration content. Furthermore, solubility and swelling properties investigation of the beads were also performed within the prescribed time of 24h in three different medium which were acidic, distilled water and alkaline solution. Result of solubility test proved that PVA/CS/TiO2 beads were insoluble only in distilled water and alkaline solution. However, the beads were found to dissolve in acidic solution due to the CS content. Meanwhile, the swelling test revealed that increased concentration of CS leads to swelling of beads in distilled water and alkaline solution. Results revealed that beads with the highest CS composition which is 2.5 g recorded 82.6% and 118.4% of swelling in distilled water and alkaline solution, respectively. In the mean time, beads with the lowest CS composition which is 1.0 g only swell for 65.8% and 93.3% in distilled water and alkaline solution, respectively. As a conclusion, the synthesised beads in this study is feasible to be applied in natural to alkaline environment.

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