Modifications in the correlation function in poly(vinyl alcohol)/silica hybrid wet gels

2008 ◽  
Vol 42 (1) ◽  
pp. 10-14 ◽  
Author(s):  
Dimas R. Vollet ◽  
Dario A. Donatti ◽  
Alberto Ibañez Ruiz
Keyword(s):  
Correlation Function ◽  
Vinyl Alcohol ◽  
Basic Structure ◽  
Poly Vinyl Alcohol ◽  
Fractal Structures ◽  
Structural Modifications ◽  
X Ray Scattering ◽  
Mass Fractal ◽  
Large Correlation ◽  
First Time

Small-angle X-ray scattering was used to study structural modifications in tetraethoxysilane-derived poly(vinyl alcohol) (PVA)/silica hybrids. The basic structure of the wet gels can be described as a mass-fractal structure with fractal dimensionDequal to 2 and characteristic length ξ, which increases with addition of PVA. Wet gels with high PVA content exhibit a positive deviation from the mass-fractal power-law scattering at lowq; this deviation is associated with additional scattering due to a second large correlation distance ζ, reinforced by the addition of PVA. The fraction of both contributions to the total correlation function was estimated; this is the first time that such a study has been carried out for mass-fractal structures.

Free volume and lamellar structure of poly vinyl alcohol-nanosized BaTiO3 composite: Positron annihilation and small angle X-ray scattering study

2016 ◽  
Vol 84 ◽  
pp. 100-110 ◽  
Author(s):  
Sandeep K. Sharma ◽  
Jyoti Prakash ◽  
Jitendra Bahadur ◽  
Manjulata Sahu ◽  
Subhashish Mazumder ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Small Angle ◽  
Vinyl Alcohol ◽  
Lamellar Structure ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Defining Structure in Electrospun Polymer Fibres

2008 ◽  
Vol 55-57 ◽  
pp. 33-36
Author(s):  
G.R. Mitchell ◽  
M. Belal ◽  
F.J. Davis ◽  
D.E. Elliott ◽  
M. Kariduraganavar ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Polyethylene Oxide ◽  
Self Assembly ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
Amorphous System ◽  
Composite Systems ◽  
X Ray Scattering ◽  
Nano Size

We use a combination of microscopy, x-ray scattering and neutron scattering to show how structure develops in micro and nano-size polymer fibres prepared by electrospinning. The technique has been applied to a range of different polymers, an amorphous system (polystyrene), a crystallisable polymer (poly-ε-caprolactone), a composite systems (polyethylene oxide or poly vinyl alcohol containing polypyrrole) and consider the possibility of self assembly (gelatin).

Thermo- and water-induced shape memory poly(vinyl alcohol) supramolecular networks crosslinked by self-complementary quadruple hydrogen bonding

2016 ◽  
Vol 7 (43) ◽  
pp. 6637-6644 ◽  
Author(s):  
Hongmei Chen ◽  
Ying Li ◽  
Gong Tao ◽  
Lin Wang ◽  
Shaobing Zhou
Keyword(s):  
Hydrogen Bonding ◽  
Shape Memory ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Donor Acceptor ◽  
Quadruple Hydrogen Bonding ◽  
Supramolecular Networks ◽  
First Time

Poly(vinyl alcohol) (PVA) supramolecular networks cross-linked by ureido-pyrimidinone (UPy) dimers via strong quadruple hydrogen bonding in donor–donor–acceptor–acceptor (DDAA) arrays have been synthesized for the first time.

Mussel inspired locomotive: the moisture induced actuation in a poly(vinyl alcohol) film containing melanin-like dopamine nano spheres

RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 65089-65094 ◽  
Author(s):  
Francis O. Obiweluozor ◽  
Amin GhavamiNejad ◽  
Chan Hee Park ◽  
Cheol Sang Kim
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Perpetual Motion ◽  
Humidity Gradient ◽  
First Time

We report here for the first time a PVA film incorporated with PDNs that is capable of fast and perpetual motion driven by a humidity gradient.

Structuring in poly(vinyl alcohol)-potassium iodide-iodine systems: Small-angle X-ray-scattering study

2011 ◽  
Vol 53 (9) ◽  
pp. 787-790
Author(s):  
N. N. Bozhko ◽  
V. P. Stolyarov ◽  
E. B. Bablyuk ◽  
V. G. Nazarov ◽  
V. V. Volkov ◽  
...  
Keyword(s):  
Potassium Iodide ◽  
Small Angle ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Evaluation of Thermally Crosslinked Poly(Acrylic Acid-Co-Maleic Acid) (PAMA)/Poly(Vinyl Alcohol) (PVA) Microneedle Arrays

2019 ◽  
Vol 819 ◽  
pp. 45-50 ◽  
Author(s):  
Nway Nway Aung ◽  
Yin Yin Myat ◽  
Tanasait Ngawhirunpat ◽  
Theerasak Rojanarata ◽  
Prasopchai Patrojanasophon ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Maleic Acid ◽  
Vinyl Alcohol ◽  
Transdermal Drug Delivery ◽  
Poly Vinyl Alcohol ◽  
Optimal Conditions ◽  
Microneedle Arrays ◽  
First Time ◽  
Polymer Ratio ◽  
Poly Acrylic Acid

This study aimed to evaluate the optimal conditions for crosslinked of PAMA/PVA microneedle (MN) arrays. Poly (acrylic acid-co-maleic acid) (PAMA)/poly (vinyl alcohol) (PVA) MN arrays were fabricated for the first time using the micromolding technique. The PAMA/PVA MN arrays at the polymer ratio of 1:4 were sharp, homogenous and perfectly formed with an elegant appearance. The successfully crosslinking MN arrays were determined using FTIR and water insolubilization. The results showed that increasing the crosslinking temperature and time, the degree of crosslinking also improved, which results in a decline in water uptake. The optimal crosslinking condition for PAMA/PVA MN arrays was 130°C for 1 h. Moreover, the highest swelling was observed from crosslinked PAMA/PVA MN arrays at 90°C for 0.5 h. These studies suggest that the combination of PAMA and PVA for fabrication of MN arrays could have a great potential to develop both hydrogel and dissolving MN devices for transdermal drug delivery.

Structural Modifications in Silica Sonogels Prepared with Additions of Poly(vinyl alcohol)

2008 ◽  
Vol 112 (10) ◽  
pp. 3552-3557 ◽  
Author(s):  
J. A. Portella ◽  
D. A. Donatti ◽  
A. Ibañez Ruiz ◽  
D. R. Vollet
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Structural Modifications
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