Correlation between the ion permeation and free volume property in ethyl cellulose film during the acid treatment

2019 ◽  
Vol 3 (8) ◽  
pp. 1518-1522 ◽  
Author(s):  
Jieyu Liu ◽  
Zhe Chen ◽  
Lei Yao ◽  
Jingjing Li ◽  
Jinshuai Zhang ◽  
...  

A correlation between the ion permeation and free-volume hole size was found by theoretical deduction and confirmed by the corresponding experiment.

1998 ◽  
Vol 10 (46) ◽  
pp. 10443-10450 ◽  
Author(s):  
G Dlubek ◽  
M Stolp ◽  
Ch Nagel ◽  
H M Fretwell ◽  
M A Alam ◽  
...  

2019 ◽  
Vol 13 (27) ◽  
pp. 157-163
Author(s):  
Hayder S. Hussain

Positron annihilation lifetime (PAL) technique has been employed tostudy the microstructural changes of polyurethane (PU), EUXIT 101and epoxy risen (EP), EUXIT 60 by Gamma-ray irradiation with thedose range (95.76 - 957.6) kGy. The size of the free volume hole andtheir fraction in PU and EP were determined from ortho-positroniumlifetime component and its intensity in the measured lifetime spectra.The results show that the irradiation causes significant changes in thefree volume hole size (Vh) and the fractional free volume (Fh), andthereby the microstructure of PU and EP. The results indicate thatthe γ-dose increases the crystallinity in the amorphous regions of PUand increase the cross-linking of EP.


2008 ◽  
Vol 607 ◽  
pp. 67-69
Author(s):  
Ren Wu Zhang ◽  
Patrick Bell ◽  
Justin R. Proirie ◽  
Paul M. Johnson ◽  
Lindsay A. Everhart ◽  
...  

Different polyamide water separation films were prepared by interfacial polymerization by using different concentrations of Ethylenediamine (EDA)/H2O and some Trimesoylchloride (TMC)/Toluene on the modified Polyacronitrile (mPAN) substrates. By applying a slow positron beam, depth profiles of relative free volume hole sizes for different films were obtained. It was found that the hole size at the skin polyamide layer was almost identical and much smaller than that in the mPAN substrate layer. The results indicate that the thickness of the polyamide layer is the major factor in controlling the performance of a membrane during water separation.


1996 ◽  
Vol 157 (2) ◽  
pp. 351-364 ◽  
Author(s):  
G. Dlubek ◽  
A. P. Clarke ◽  
H. M. Fretwell ◽  
S. B. Dugdale ◽  
M. A. Alam

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