scholarly journals Physico-chemical characteristics of gamma irradiation crosslinked poly(vinyl alcohol)/magnetite ferrogel composite

2014 ◽  
Vol 68 (6) ◽  
pp. 743-753 ◽  
Author(s):  
Milena Marinovic-Cincovic ◽  
Aleksandra Radosavljevic ◽  
Jelena Krstic ◽  
Jelena Spasojevic ◽  
Natasa Bibic ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Vinyl Alcohol ◽  
Magnetic Particles ◽  
Heating Temperature ◽  
Crosslinking Agent ◽  
Poly Vinyl Alcohol ◽  
Chemical Characteristics ◽  
Physico Chemical ◽  
Soft Actuators ◽  
Pva Hydrogel

Magnetic field sensitive gels, ferrogels are new promising class of hydrogels. The coupling of hydrogels and magnetic particles has potential application in soft actuators such as artificial muscles or for hyperthermia application. Here a composite of magnetite particles (Fe3O4) and poly(vinyl alcohol) (PVA) hydrogel is developed using gamma irradiation as a crosslinking agent. PVA and Fe3O4 were chosen because of their well-established biocompatibility, radiation crosslinking potential (PVA), mild magnetic properties and the Curie point near desired heating temperature range (Fe3O4). Physico-chemical characteristics of these systems show the effect of the presence of particles in the process of radiation-induced crosslinking. Obtained PVA/Fe3O4 ferrogel composite has greater swelling capacity, activation energy of dehydration and dehydration rate compared to PVA hydrogel, crosslinked under the same conditions.

scholarly journals Impact of the Type of Crosslinking Agents on the Properties of Modified Sodium Alginate/Poly(vinyl Alcohol) Hydrogels

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2381
Author(s):  
Katarzyna Bialik-Wąs ◽  
Ewelina Królicka ◽  
Dagmara Malina
Keyword(s):  
Sodium Alginate ◽  
Aqueous Extract ◽  
Vinyl Alcohol ◽  
Crosslinking Agent ◽  
Echinacea Purpurea ◽  
Poly Vinyl Alcohol ◽  
Spectra Analysis ◽  
Natural Origin ◽  
Glycol Diacrylate ◽  
Soxhlet Apparatus

Here, we report on studies on the influence of different crosslinking methods (ionic and chemical) on the physicochemical (swelling ability and degradation in simulated body fluids), structural (FT-IR spectra analysis) and morphological (SEM analysis) properties of SA/PVA hydrogels containing active substances of natural origin. First, an aqueous extract of Echinacea purpurea was prepared using a Soxhlet apparatus. Next, a series of modified SA/PVA-based hydrogels were obtained through the chemical crosslinking method using poly(ethylene glycol) diacrylate (PEGDA, Mn = 700 g/mol) as a crosslinking agent and, additionally, the ionic reaction in the presence of a 5% w/v calcium chloride solution. The compositions of SA/PVA/E. purpurea-based hydrogels contained a polymer of natural origin—sodium alginate (SA, 1.5% solution)—and a synthetic polymer—poly(vinyl alcohol) (PVA, Mn = 72,000 g/mol, 10% solution)—in the ratio 2:1, and different amounts of the aqueous extract of E. purpurea—5, 10, 15 or 20% (v/v). Additionally, the release behavior of echinacoside from the polymeric matrix was evaluated in phosphate-buffered saline (PBS) at 37 °C. The results indicate that the type of the crosslinking method has a direct impact on the release profile. Consequently, it is possible to design a system that delivers an active substance in a way that depends on the application.

scholarly journals Linear Dynamic Viscoelasticity of Dual Cross-Link Poly(Vinyl Alcohol) Hydrogel with Determined Borate Ion Concentration

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 71
Author(s):  
Takuro Taniguchi ◽  
Kenji Urayama
Keyword(s):  
Vinyl Alcohol ◽  
Ion Concentration ◽  
Poly Vinyl Alcohol ◽  
Relaxation Dynamics ◽  
Cross Link ◽  
Dynamic Viscoelasticity ◽  
Linear Dynamic ◽  
Cross Links ◽  
Pva Gel ◽  
Pva Hydrogel

We investigated the linear dynamic viscoelasticity of dual cross-link (DC) poly(vinyl alcohol) (PVA) (DC-PVA) hydrogels with permanent and transient cross-links. The concentrations of incorporated borate ions to form transient cross-links in the DC-PVA hydrogels (CBIN) were determined by the azomethine-H method. The dynamic viscoelasticity of the DC-PVA hydrogel cannot be described by a simple sum of the dynamic viscoelasticity of the PVA gel with the same permanent cross-link concentration and the PVA aqueous solution with the same borate ion concentration (CB = CBIN) as in the DC-PVA gel. The DC-PVA hydrogel exhibited a considerably higher relaxation strength, indicating that the introduction of permanent cross-links into temporary networks increases the number of viscoelastic chains with finite relaxation times. In contrast, the relaxation frequency (ωc) (given by the frequency at the maximum of loss modulus) for the DC-PVA hydrogel was slightly lower but comparable to that for a dilute PVA solution with the same CB. This signifies that the relaxation dynamics of the DC-PVA hydrogels is essentially governed by the lifetime of an interchain transient cross-link (di-diol complex of boron). The effect of permanent cross-linking on the relaxation dynamics was observed in the finite broadening of the relaxation-time distribution in the long time region.

Wear Reduction by Functional Protein Boundary Film on Poly(Vinyl Alcohol) Hydrogel

2005 ◽  
Author(s):  
K. Nakashima ◽  
Y. Sawae ◽  
T. Murakami
Keyword(s):  
Vinyl Alcohol ◽  
Film Formation ◽  
Glass Plate ◽  
Poly Vinyl Alcohol ◽  
Functional Protein ◽  
Adsorbed Film ◽  
Adsorption Condition ◽  
Boundary Film ◽  
Joint Prostheses ◽  
Pva Hydrogel

Poly(vinyl alcohol) (PVA) hydrogel is a candidate material for artificial cartilage of joint prostheses. From previous researches [1–4] it is shown that the wear of PVA hydrogel depends on the concentration of proteins in lubricants. Therefore it is considered that the adsorbed film formation by protein of albumin or γ-globulin influences upon the wear grade of PVA hydrogel. The remaining film of proteins on the glass plate was observed in fluorescence microscope. The adsorption condition of albumin and γ-globulin was different. The adsorbed film with effective reduction of the wear showed cooperative stratification of albumin and γ-globulin, but the condition of increased the wear showed separation of albumin and γ-globulin. Consequently, to reduce the wear of PVA hydrogel, cooperative stratification layers are effective.

scholarly journals Effect of gamma irradiation on thermal properties of poly(vinyl alcohol) solutions

1991 ◽  
Vol 43 (7) ◽  
pp. 1393-1395
Author(s):  
Mohyi A. Kenawy ◽  
Amira Z. Dakroury ◽  
Massarat B. S. Osman
Keyword(s):  
Thermal Properties ◽  
Gamma Irradiation ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol

Improving the Compatibility of Zein/Poly(vinyl alcohol) Blends by Gamma Irradiation and Graft Copolymerization of Acrylic Acid

2010 ◽  
Vol 58 (7) ◽  
pp. 4470-4476 ◽  
Author(s):  
Magdy M. Senna ◽  
Stephane Salmieri ◽  
Abdel-Wahab El-naggar ◽  
Agnes Safrany ◽  
Monique Lacroix
Keyword(s):  
Acrylic Acid ◽  
Gamma Irradiation ◽  
Vinyl Alcohol ◽  
Graft Copolymerization ◽  
Poly Vinyl Alcohol
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