Free volume and damping in a miscible high performance polymer blend: Positron annihilation lifetime and dynamic mechanical thermal analysis studies

2015 ◽  
Vol 133 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Ramasubbu Ramani ◽  
Sarfaraz Alam
Keyword(s):  
Thermal Analysis ◽  
Positron Annihilation ◽  
Free Volume ◽  
Polymer Blend ◽  
Dynamic Mechanical Thermal Analysis ◽  
High Performance ◽  
Positron Annihilation Lifetime ◽  
Dynamic Mechanical ◽  
High Performance Polymer

Biosourced graphitic nanoparticle loaded hyperbranched polyurethane composites – application as multifunctional high-performance coatings

2015 ◽  
Vol 39 (9) ◽  
pp. 7219-7226 ◽  
Author(s):  
Srinivasarao Pilla ◽  
Rohit Ranganathan Gaddam ◽  
Ramanuj Narayan ◽  
Chepuri R. K. Rao ◽  
K. V. S. N. Raju
Keyword(s):  
Thermal Analysis ◽  
Dynamic Mechanical Thermal Analysis ◽  
High Performance ◽  
Dynamic Mechanical ◽  
Hyperbranched Polyurethane ◽  
Drastic Increase ◽  
Polyurethane Composites

Dynamic mechanical thermal analysis of GP-PU depicting a drastic increase in E′ and Tg with minuscule incorporation of GP-COOH.

THE STRUCTURAL DEVELOPMENT OF NYLON6/LAYERED SILICATE NANOCOMPOSITE DURING ZONE-DRAWING

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4577-4582
Author(s):  
SUNG SOO HAN ◽  
YANG-WHAN CHO ◽  
SOO-YOUNG PARK
Keyword(s):  
Thermal Analysis ◽  
Dynamic Mechanical Thermal Analysis ◽  
Crystalline Phase ◽  
Layered Silicate ◽  
Phase Region ◽  
Structural Development ◽  
X Ray ◽  
Dynamic Mechanical ◽  
X Ray Scattering ◽  
Degree Of Orientation

The structural development of nylon6/layered silicate nanocomposite during zone-drawing was studied using X-ray scattering and dynamic mechanical thermal analysis. The γ form, which was favored in the pressed film, was converted into the α form during zone-drawing. The newly developed α form, during zone-drawing, has a better orientation than the existing γ form, thus supporting the claim that the α form crystallizes away from the polymer-silicate inter-phase region during drawing. The degree of orientation of the layered silicate, projected along the TD direction, increases with the increase of the draw ratio, suggesting that the layered silicate has become straighter during zone-drawing, although the layered silicate within the zone-drawn film buckled perpendicular to the draw direction. The β transition of the dynamic mechanical thermal analysis is independent of the crystalline phase, although the α transition is strongly dependent upon the crystalline phase. This can be explained by the free volume that exists in the inter-phase between the γ lamellar and the layered silicate.

Preliminary Positron Lifetime Results on Free Volumes in Cyclodextrins

2010 ◽  
Vol 666 ◽  
pp. 99-102 ◽  
Author(s):  
Maria Fatima Ferreira Marques ◽  
A.M.G. Moreira Da Silva ◽  
P.M. Gordo ◽  
Z. Kajcsos
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Positron Lifetime ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Positron Source ◽  
Lifetime Component ◽  
Positron Annihilation Lifetime ◽  
Long Lifetime

Positron annihilation lifetime spectroscopy was used to study the free-volume parameters in various pure -, - and -cyclodextrins samples and, in the case of β-cyclodextrin, with inclusion of S-carvone and thymoquinone. The results clearly indicate the presence of long lifetime components related to Ps-formation. The data show that the addition of S-carvone to β-cyclodextrin results in a decrease of o-Ps lifetime that we ascribe to a reduction of free volume holes from 81.8 to 63.7 Å3. The long lifetime component disappears when thymoquinone is added to -cyclodextrin, indicating this substance acts as an o-Ps quencher. For all samples studied, a decrease in the long lifetime component values was observed with increasing source in situ time, a result that might be attributed to the irradiation of the sample by the 22Na positron source.

Ceramide increases free volume voids in DPPC membranes

RSC Advances ◽  
2015 ◽  
Vol 5 (55) ◽  
pp. 44282-44290 ◽  
Author(s):  
E. Axpe ◽  
A. B. García-Arribas ◽  
J. I. Mujika ◽  
D. Mérida ◽  
A. Alonso ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Lipid Membranes ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Positron Annihilation Lifetime

We have measured by positron annihilation lifetime spectroscopy (PALS) that ceramide increases the size of the free volume holes in DPPC lipid membranes.

Sign in / Sign up

Export Citation Format

Share Document