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.

Properties of Vanillin Modified Poly(vinyl Alcohol)/Gelatin Composite

2013 ◽  
Vol 327 ◽  
pp. 48-52
Author(s):  
Lin Cheng ◽  
Qin Zou ◽  
Li Kou Zou ◽  
Yan Luo ◽  
Li Qiang Kan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Hydrogen Bonding ◽  
Cartilage Repair ◽  
Vinyl Alcohol ◽  
Homogeneous System ◽  
Poly Vinyl Alcohol ◽  
Composite Gels ◽  
Pva Gel ◽  
Pva Hydrogel

To improve the cytocompatibility of super-hydrophilic poly (vinyl alcohol) (PVA) hydrogel, PVA/gelatin (PVA/Gel) composite was modified by vanillin (PVA/Gel/V) in this study. The properties of the composite gels were characterized by SEM, FTIR, DSC and contact angle instrument. The results show that PVA/Gel/V composite can compose a homogeneous system with the addition of vanillin, accompanying some destroy of the intra-hydrogen bonding of PVA crystal molecular chains and decrease of PVA super hydrophilicity. PVA/Gel/V composite exhibits better miscibility and hydrophobicity than pure PVA and PVA/Gel. The modified PVA/Gel/V composite may have a promising prospect for future cartilage repair.

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 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 Dynamic Viscoelasticity of Syndiotactic Poly(vinyl alcohol) Derived from Vinyl Pivalate.

1997 ◽  
Vol 53 (5) ◽  
pp. 195-203 ◽  
Author(s):  
Ryohei Fukae ◽  
Tohei Yamamoto ◽  
Hitoshi Masago ◽  
Nobuhiro Kawatsuki ◽  
Osamu Sangen ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Dynamic Viscoelasticity

Co-electrospun-electrosprayed PVA/folic acid nanofibers for transdermal drug delivery: Preparation, characterization, and in vitro cytocompatibility

2021 ◽  
pp. 152808372199718
Author(s):  
Fatma Nur Parın ◽  
Çiğdem İnci Aydemir ◽  
Gökçe Taner ◽  
Kenan Yıldırım
Keyword(s):  
Folic Acid ◽  
Polymer Matrix ◽  
Vinyl Alcohol ◽  
Matrix Material ◽  
In Vitro Study ◽  
Poly Vinyl Alcohol ◽  
Electrospun Fibers ◽  
Pva Gel ◽  
Fast Release

In this study, hydrophilic based bioactive nanofibers were produced via an electrospinning and electrospraying simultaneous process. Poly(vinyl alcohol) (PVA), poly(vinyl alcohol)-gelatin (PVA-Gel), and poly(vinyl alcohol)-alginate (PVA-Alg) polymers were used as the matrix material and folic acid (FA) particles were dispersed simultaneously on the surface of the nanofibers. The morphology of the nanofibers (NFs) was uniform and confirmed by scanning electron microscopy. Thermal behavior, chemical structure of the composite nanofibers were investigated by thermogravimetric analysis, and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy which showed that no chemical bonding between vitamin and polymers. A fast release of FA-loaded electrospun fibers was carried out by UV-Vis in vitro study within the 8 hour-period in artificial sweat solutions (pH 5.44). The obtained PVA/FA, PVA-Gel/FA, and PVA-Alg/FA fibers released 49.6%, 69.55%, and 50.88% of the sprayed FA in 8 h, indicating the influence of polymer matrix and polymer-drug interactions, on its release from the polymer matrix. Moreover, biocompatibility of all developed novel NFs was assessed by two different cytotoxicity tests, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and neutral red uptake (NRU) assay in L929 (mouse fibroblasts) cell lines. In all cases, it is concluded that these new electrospun fibers had fast-release of the vitamin and the hybrid process is suitable for transdermal patch applications, especially for skin-care products. The results of cytocompatibility assays on L929 reveal that all prepared NFs have no or slight cell toxicity. PVA and PVA-Gel with/without FA nanofibers seems more biocompatible than PVA-Alg nanofibers.

scholarly journals Highly Stretchable and Self-Healing Strain Sensors Based on Nanocellulose-Supported Graphene Dispersed in Electro-Conductive Hydrogels

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 937 ◽  
Author(s):  
Chunxiao Zheng ◽  
Yiying Yue ◽  
Lu Gan ◽  
Xinwu Xu ◽  
Changtong Mei ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Cellulose Nanofibers ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Composite Gels ◽  
Highly Stretchable ◽  
Conductive Hydrogels ◽  
Pva Hydrogel

Intrinsic self-healing and highly stretchable electro-conductive hydrogels demonstrate wide-ranging utilization in intelligent electronic skin. Herein, we propose a new class of strain sensors prepared by cellulose nanofibers (CNFs) and graphene (GN) co-incorporated poly (vinyl alcohol)-borax (GN-CNF@PVA) hydrogel. The borax can reversibly and dynamically associate with poly (vinyl alcohol) (PVA) and GN-CNF nanocomplexes as a cross-linking agent, providing a tough and flexible network with the hydrogels. CNFs act as a bio-template and dispersant to support GN to create homogeneous GN-CNF aqueous dispersion, endowing the GN-CNF@PVA gels with promoted mechanical flexibility, strength and good conductivity. The resulting composite gels have high stretchability (break-up elongation up to 1000%), excellent viscoelasticity (storage modulus up to 3.7 kPa), rapid self-healing ability (20 s) and high healing efficiency (97.7 ± 1.2%). Due to effective electric pathways provided by GN-CNF nanocomplexes, the strain sensors integrated by GN-CNF@PVA hydrogel with good responsiveness, stability and repeatability can efficiently identify and monitor the various human motions with the gauge factor (GF) of about 3.8, showing promising applications in the field of wearable sensing devices.

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