Structure and Properties of Poly(vinyl alcohol) Hydrogels Obtained by Freeze/Thaw Techniques

2005 ◽  
Vol 222 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Rosa Ricciardi ◽  
Finizia Auriemma ◽  
Claudio De Rosa
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties ◽  
Freeze Thaw

Graphene Oxide Containing Composite Hydrogel Fabricated by Freeze/Thaw Method

2012 ◽  
Vol 430-432 ◽  
pp. 1028-1031 ◽  
Author(s):  
Wen Chao Wang ◽  
Zhi Liang Li ◽  
Jian Juan Wu ◽  
Mao Cong Yi ◽  
Yu Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Graphene Oxide ◽  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
Load Transfer ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties ◽  
Freeze Thaw ◽  
Composite Hydrogels ◽  
Inorganic Fillers

Graphene oxide (GO) was used as inorganic fillers to enhance the mechanic properties of graphene oxide/poly(vinyl alcohol) composite hydrogels that were prepared by freeze/thaw method. The structure and properties of the composite hydrogels were characterized. Since GO was well dispersed in polymer matrix, the composite hydrogels showed an outstanding mechanical improvement. Significant increase in Young's modulus and compressive strength was achieved, indicating a good load transfer between fillers and matrix.

Structure and Properties of Starch/Poly (vinyl alcohol) Film Modificated by Different Inorganic Salts

2019 ◽  
Vol 4 (2) ◽  
pp. 600-607 ◽  
Author(s):  
Wenhao Du ◽  
Ting Jiang ◽  
Mengke Shi ◽  
Zhaojie Yang ◽  
Xi Zhang
Keyword(s):  
Vinyl Alcohol ◽  
Inorganic Salts ◽  
Poly Vinyl Alcohol ◽  
Structure And Properties

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.

scholarly journals Drug Release from Freeze-Thaw Poly (vinyl alcohol) Gel

1987 ◽  
Vol 107 (3) ◽  
pp. 233-237 ◽  
Author(s):  
AKIRA TAKAMURA ◽  
MOTOHARU ARAI ◽  
FUMIYOSHI ISHII
Keyword(s):  
Drug Release ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Freeze Thaw

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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