One-Step Mild Preparation of Tough and Reversible Poly(vinyl alcohol) Hydrogels Induced by Small Molecules

2021 ◽  
Author(s):  
Chuang Dong ◽  
Jiahua Zhou ◽  
Dongjian Shi ◽  
Yufang Song ◽  
Xi Yu ◽  
...  
Keyword(s):  
Small Molecules ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Freeze Thaw ◽  
One Step ◽  
Pva Hydrogel

To overcome shortcomings of traditinal freeze-thaw method for PVA hydrogel preparation, we develop a one-step mild method, which induces PVA crystallization to form hydrogels through small molecules containing hydroxyl and...

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.

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.

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 One-step fabrication and characterization of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning for multifunctional applications

RSC Advances ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. 4830-4839 ◽  
Author(s):  
Chun-Gang Yuan ◽  
Shiwei Guo ◽  
Jian Song ◽  
Can Huo ◽  
Yukai Li ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
One Step ◽  
Fabrication And Characterization ◽  
Hybrid Nanofiber

Preparation and application of a poly(vinyl alcohol)/silver hybrid nanofiber mat by electrospinning.

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

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

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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