Controlled mechanical and swelling properties of poly(vinyl alcohol)/sodium alginate blend hydrogels prepared by freeze-thaw followed by Ca2+ crosslinking

2011 ◽  
Vol 124 (1) ◽  
pp. 823-831 ◽  
Author(s):  
Liang Xie ◽  
Man Jiang ◽  
Xiaogang Dong ◽  
Xia Bai ◽  
Jin Tong ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Swelling Properties ◽  
Freeze Thaw

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 Enhancing the Freeze-Thaw Durability of Concrete Through Ice Recrystallization Inhibition by Poly(vinyl Alcohol)

2019 ◽  
Author(s):  
Zhengyao Qu ◽  
Shuaiqi Guo ◽  
Christian C. M. Sproncken ◽  
Romà Surís-Valls ◽  
qingliang yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vinyl Alcohol ◽  
Cement Hydration ◽  
Poly Vinyl Alcohol ◽  
Seasonal Temperature ◽  
Ice Recrystallization Inhibition ◽  
Ice Recrystallization ◽  
Freeze Thaw ◽  
Recrystallization Inhibition ◽  
Durability Of Concrete

Frost weathering of porous materials caused by seasonal temperature changes is a major source of damage to the world’s infrastructure and cultural heritage. Here we investigate poly(vinyl alcohol) (PVA) addition as a means to enhance the freeze-thaw durability of concrete without compromising its structural or mechanical integrity. We evaluate the ice recrystallization inhibition activity of PVA in a cementitious environment and the impact of PVA on key structural and mechanical properties, such as cement hydration (products), microstructure, strength, as well as freeze‑thaw resistance. We find that a low amount of PVA significantly reduces the surface scaling of concrete and displays excellent ice recrystallization inhibition in the saturated Ca(OH)<sub>2 </sub>solution which has a similar pH value as cement pore solution, while it does not affect cement hydration, microstructure, nor its mechanical properties. These findings contribute to new insights on freeze-thaw damage mechanism and more importantly we disclose a new direction for the design of concrete with excellent freeze‑thaw resistance.

Preparation of sodium alginate-poly (vinyl alcohol) blend beads for base-triggered release of dinotefuran in Spodoptera litera midgut

2020 ◽  
Vol 202 ◽  
pp. 110935 ◽  
Author(s):  
Shiying Wang ◽  
Qianli Ma ◽  
Ruifei Wang ◽  
Qizhan Zhu ◽  
Liupeng Yang ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Triggered Release

scholarly journals Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1149
Author(s):  
Ludovico Esposito ◽  
Ana Isabel Barbosa ◽  
Tânia Moniz ◽  
Sofia Costa Lima ◽  
Paulo Costa ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Fruits And Vegetables ◽  
Radical Scavenging ◽  
Entrapment Efficiency ◽  
Interesting Property ◽  
Poly Vinyl Alcohol ◽  
Skin Delivery ◽  
Potential Applications

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel’s blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

Methylene blue removal from water using the hydrogel beads of poly(vinyl alcohol)-sodium alginate-chitosan-montmorillonite

2018 ◽  
Vol 198 ◽  
pp. 518-528 ◽  
Author(s):  
Wei Wang ◽  
Yunliang Zhao ◽  
Haoyu Bai ◽  
Tingting Zhang ◽  
Valentin Ibarra-Galvan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Hydrogel Beads ◽  
Methylene Blue Removal

Fabrication and characterization of 3D scaffolds made from blends of sodium alginate and poly(vinyl alcohol)

2019 ◽  
Vol 19 ◽  
pp. 56-61 ◽  
Author(s):  
Ji Min Seok ◽  
Se Heang Oh ◽  
Sang Jin Lee ◽  
Jun Hee Lee ◽  
Wan Doo Kim ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
3D Scaffolds ◽  
Fabrication And Characterization
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