scholarly journals Insightful understanding of the correlations of the microstructure and catalytic performances of Pd@chitosan membrane catalysts studied by positron annihilation spectroscopy

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 3225-3236 ◽  
Author(s):  
Qi Liu ◽  
Mengdie Xu ◽  
Jing Zhao ◽  
Yudong Wang ◽  
Chenze Qi ◽  
...  
Keyword(s):  
Mass Transport ◽  
Positron Annihilation ◽  
Free Volume ◽  
Positron Annihilation Spectroscopy ◽  
Membrane Catalyst ◽  
Chitosan Membrane ◽  
Transport Channels ◽  
Catalytic Performances

A number of instantaneously connected free volume holes act as mass transport channels of the Pd0@CS membrane catalyst in reactions.

scholarly journals Free-volume Characterization of Polysilanes Using Positron Annihilation Spectroscopy.

1999 ◽  
Vol 12 (5) ◽  
pp. 739-742
Author(s):  
Mutsumi Tashiro ◽  
Shu Seki ◽  
Pradeep K. Pujari ◽  
Yoshihide Honda ◽  
Seiichi Tagawa
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Positron Annihilation Spectroscopy

Crosslinked PVA/SSA proton exchange membranes: correlation between physiochemical properties and free volume determined by positron annihilation spectroscopy

2018 ◽  
Vol 20 (44) ◽  
pp. 28287-28299 ◽  
Author(s):  
Mahmoud M. Gomaa ◽  
Christoph Hugenschmidt ◽  
Marcel Dickmann ◽  
Esam E. Abdel-Hady ◽  
Hamdy F. M. Mohamed ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Positron Annihilation Spectroscopy ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Water Molecules ◽  
High Humidity ◽  
Physiochemical Properties ◽  
Low Humidity ◽  
Volume Size

At low humidity (<30 RH%), water molecules begin to fill the intermolecular spaces in the membrane. At high humidity (80 RH%) the membrane swells; the free volume size increases.

scholarly journals Study of multiblock polyamide-6/Poly-(isoprene) copolymers by positron annihilation spectroscopy

2008 ◽  
Vol 6 (4) ◽  
pp. 575-580 ◽  
Author(s):  
R. Bryaskova ◽  
R. Mateva ◽  
N. Djourelov ◽  
M. Krasteva
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Main Chain ◽  
Positron Annihilation Spectroscopy ◽  
Polyamide 6 ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Degree Of Crystallinity ◽  
Doppler Broadening ◽  
Annihilation Line ◽  
Positron Annihilation Lifetime

AbstractPositron annihilation lifetime spectroscopy (PALS) has been used to determine the free volume in multiblock polyamide-6/poly-(isoprene) copolymers (PA-6/PI), synthesized via activated anionic bulk copolymerization. The diisocyanate functionalized telechelic PI, blocked with caprolactam (CL) has been used as a commoner and an activator at the same time. The elastic PI block incorporated into the main chain of PA-6 affects the amorphous and crystal phase of the copolymer leading to changing in degree of crystallinity. The positron annihilation lifetime spectroscopy (PAL) and Doppler broadening of annihilation line (DBAL) technique in a set of pure PA-6 and PA-6/PI copolymers with two different compositions have been applied and evaluation of the size of free-volume holes (pores), localized mainly in the disordered regions of the PA-6/PI copolymer by measuring the o-Ps lifetime (τ3) and o-Ps intensity (I3) has been performed.

The Depth Profile of Free Volume in Drug Delivery Polymers Studied by Positron Annihilation Spectroscopy

2004 ◽  
Vol 445-446 ◽  
pp. 319-321 ◽  
Author(s):  
Ying Li ◽  
R. Zhang ◽  
H. Chen ◽  
J. Zhang ◽  
Ryoichi Suzuki ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Positron Annihilation ◽  
Free Volume ◽  
Depth Profile ◽  
Positron Annihilation Spectroscopy
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