1H NMR Self-diffusion Study of PVA Cryogels Containing Ethylene Glycol and Its Oligomers

Shapiro, Yury E.; Shapiro, Tatyana I

doi:10.1006/jcis.1999.6391

Cited by 17 publications

(13 citation statements)

References 22 publications

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“…Pristine PVA has characteristic CH 2 doublet at chemical shift value δH 1.37 while the DMSO solvent resonates at δH 2.5 and water at δH 3.16. CH has demonstrated triplet at δH 3.8 due to shielding by OH while OH has furnished peak at δH 4.1 [ 54 , 55 ].…”

Section: Resultsmentioning

confidence: 99%

Starch-Capped Silver Nanoparticles Impregnated into Propylamine-Substituted PVA Films with Improved Antibacterial and Mechanical Properties for Wound-Bandage Applications

et al. 2020

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This research endeavor aims to develop polyvinyl alcohol (PVA) based films capable of blends with silver nanoparticles (Ag–NPs) for improved antibacterial properties and good mechanical strength to widen its scope in the field of wound dressing and bandages. This study reports synthesis of propylamine-substituted PVA (PA–PVA), Ag–NPs via chemical and green methods (starch capping) and their blended films in various proportions. Employment of starch-capped Ag–NPs as nanofillers into PVA films has substantially improved the above-mentioned properties in the ensuing nanocomposites. Synthesis of PA–PVA, starch-capped Ag–NPs and blended films were well corroborated with UV/Vis spectroscopy, FTIR, NMR, XRD and SEM analysis. Synthesized Ag–NPs were of particle shape and have an average size 20 nm and 40 nm via green and chemical synthesis, respectively. The successful blending of Ag–NPs was yielded up to five weight per weight into PA–PVA film as beyond this self-agglomeration of Ag–NPs was observed. Antibacterial assay has shown good antimicrobial activities by five weight per weight Ag–NPs(G)-encapsulated into PA–PVA blended film, i.e., 13 mm zone inhibition against Escherichia coli and 11 mm zone inhibition against Staphylococcus aureus. Physical strength was measured in the terms of young’s modulus via tensile stress–strain curves of blended films. The five weight per weight Ag–NPs(G)/PA–PVA blend film showed maximum tensile strength 168.2 MPa while three weight per weight Ag–NPs(G)/PVA blend film showed highest values for ultimate strain 297.0%. Ag–NPs embedment into PA–PVA was resulted in strong and ductile film blend than pristine PA–PVA film due to an increase in hydrogen bonding. These good results of five weight per weight Ag–NPs(G)/PA–PVA product make it a potent candidate for wound dressing application in physically active body areas.

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Section: Resultsmentioning

confidence: 99%

Starch-Capped Silver Nanoparticles Impregnated into Propylamine-Substituted PVA Films with Improved Antibacterial and Mechanical Properties for Wound-Bandage Applications

et al. 2020

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“…It is clear that such fillers can be either water‐immiscible, i.e., hydrophobic, or hydrophilic liquids formed upon phase separation owing to thermodynamic incompatibility of PVA and the other water‐soluble polymer in a common medium—a system similar to the well‐known Albertsson's aqueous two‐phase polymer systems 27. Whereas the latter type of composite PVA cryogels, e.g., those prepared from mixed solutions of PVA and oligoethyleneglycols,28, 29 was obtained and explored, the former type was not, to the best of our knowledge, so far reported in scientific literature. It is thought that similar filled PVACGs containing liquid hydrophobic discrete phase can be of both fundamental and applied interest, for instance, as potential wound healing or cosmetic dressings carrying medicinal or cosmetic oils, respectively 30.…”

Section: Introductionmentioning

confidence: 99%

Cryostructuring of polymer systems. XXX. Poly(vinyl alcohol)‐based composite cryogels filled with small disperse oil droplets: A gel system capable of mechanically induced releasing of the lipophilic constituents

Podorozhko

Korlyukov

Lozinsky

2010

J of Applied Polymer Sci

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Composite heterophase poly(vinyl alcohol) (PVA) cryogels containing entrapped small droplets of Vaseline oil have been prepared and studied. Such oilfilled cryogels were formed via freeze-thaw treatment of freshly prepared oil-in-water emulsions containing varied volume fraction of lipophilic phase, and the influence of the amount of this phase, as well as the effects of freezing conditions on the physicomechanical (shear moduli) and thermal (gel fusion temperature and fusion enthalpy) characteristics of resulting composites have been explored. It was shown that over certain range of PVA concentrations in aqueous phase and a range of volume fraction of the hydrophobic phase its microdroplets performed as ''active'' fillers causing an increase in both the gel strength and the heat endurance of composites. The light microscopy data on the morphological features of such filled PVA cryogels revealed the effect of diminution in size of oil droplets entrapped in the gel matrix as compared with the initial emulsions. This effect can be explained by the disintegrating action of crushing and shear stresses arising upon the system freezing and growth of ice crystals. The oil-filled PVA cryogels were found to be capable of gradually releasing the lipophilic constituents (the Rose hips oil, in this case) in response to the cyclic mechanical compression.

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“…Very similar effects, i.e., the decrease in rigidity and fusion temperature of cryoPVAGs, were observed upon addition of diol alcohol-ethylene glycol and triol alcohol-glycerol in PVA solution prior to its freeze-thaw treatment, 40 and NMR studies confirmed the cryoconcentrating phenomena for such alcohols in ULMP. 41 So, all these data testify that low molecular weight alcohols, which are water-miscible nonsolvents (precipitants) for PVA, are capable of causing the adverse effects on the formation of cryoPVAGs.…”

Section: Selection Of Experimental Conditions For the Preparation Of mentioning

confidence: 93%

Cryostructuring of polymer systems. XXVI. Heterophase organic–inorganic cryogels prepared via freezing–thawing of aqueous solutions of poly(vinyl alcohol) with added tetramethoxysilane

Lozinsky¹,

Bakeeva²,

Presnyak³

et al. 2007

J of Applied Polymer Sci

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Composite heterophase organic-inorganic hybrid cryogels of poly(vinyl alcohol) (PVA) containing silica constituents were prepared and studied. Such constituents were formed in the course of hydrolytic polycondensation (sol-gel process) of tetramethoxysilane (TMOS) introduced in to the aqueous polymer solution prior to its freezethaw treatment. It was shown that moderate (over the range of À15 to À308C) freezing, then frozen storage, and subsequent thawing of the water/PVA/TMOS systems resulted in the formation of macroporous composite cryogels filled with dispersed silica particles (discrete phase). The continuous phase of such gel materials represents the supramolecular PVA network, which is supposed to be additionally cured with the silicon-containing oligomeric cross agents formed from TMOS in the course of hydrolytic polycondensation. The incorporated silica components influenced the morphology of cryogels. The effects of significant increase in gel strength and heat resistance with increasing TMOS concentration in the initial feed and with thawing rate decreasing have also been observed.

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1H NMR Self-diffusion Study of PVA Cryogels Containing Ethylene Glycol and Its Oligomers

Cited by 17 publications

References 22 publications

Starch-Capped Silver Nanoparticles Impregnated into Propylamine-Substituted PVA Films with Improved Antibacterial and Mechanical Properties for Wound-Bandage Applications

Starch-Capped Silver Nanoparticles Impregnated into Propylamine-Substituted PVA Films with Improved Antibacterial and Mechanical Properties for Wound-Bandage Applications

Cryostructuring of polymer systems. XXX. Poly(vinyl alcohol)‐based composite cryogels filled with small disperse oil droplets: A gel system capable of mechanically induced releasing of the lipophilic constituents

Cryostructuring of polymer systems. XXVI. Heterophase organic–inorganic cryogels prepared via freezing–thawing of aqueous solutions of poly(vinyl alcohol) with added tetramethoxysilane

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