Acid–base and surface energy characterization of grafted polyethylene using inverse gas chromatography

2002 ◽  
Vol 969 (1-2) ◽  
pp. 73-80 ◽  
Author(s):  
Petra Uhlmann ◽  
Steffen Schneider
2004 ◽  
Vol 18 (1) ◽  
pp. 63-67 ◽  
Author(s):  
C. C. Puig ◽  
H. E. H. Meijer ◽  
M. A. J. Michels ◽  
L. H. G. J. Segeren ◽  
G. J. Vancso

2001 ◽  
Vol 66 (4) ◽  
pp. 259-271 ◽  
Author(s):  
A.E. Onjia ◽  
S.K. Milonjic ◽  
Lj.V. Rajakovic

The surface properties of the solid obtained from colloidal chromiawere investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II heated at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/base constants for the solidswere calculated from the IGCmeasurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar, but much greater in the case of solid I. All the sorbents had a basic character, with the KD/KA ratio decreasing in the order I > II > III. The retention and resolution in the separation of a vapour mixture of C5-C8 n-alkanes on the three substrates were different.Arapid separationwas observed on solid II and an enhanced retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface.


Cellulose ◽  
2017 ◽  
Vol 24 (11) ◽  
pp. 4691-4700 ◽  
Author(s):  
A. Legras ◽  
A. Kondor ◽  
M. Alcock ◽  
M. T. Heitzmann ◽  
R. W. Truss

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1631
Author(s):  
Vijay Kakani ◽  
Hakil Kim ◽  
Praveen Kumar Basivi ◽  
Visweswara Rao Pasupuleti

The Inverse Gas Chromatography (IGC) technique has been employed for the surface thermo-dynamic characterization of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN)) in its pure form. IGC attributes, such as London dispersive surface energy, Gibbs free energy, and Guttman Lewis acid-base parameters were analyzed for the polymer (P(VDC-co-AN)). The London dispersive surface free energy ( γ S L ) was calculated using the Schultz and Dorris–Gray method. The maximum surface energy value of (P(VDC-co-AN )) is found to be 29.93 mJ·m − 2 and 24.15 mJ·m − 2 in both methods respectively. In our analysis, it is observed that the γ S L values decline linearly with an increase in temperature. The Guttman–Lewis acid-base parameter K a , K b values were estimated to be 0.13 and 0.49. Additionally, the surface character S value and the correlation coefficient were estimated to be 3.77 and 0.98 respectively. After the thermo-dynamic surface characterization, the (P(VDC-co-AN)) polymer overall surface character is found to be basic. The substantial results revealed that the (P(VDC-co-AN)) polymer surface contains more basic sites than acidic sites and, hence, can closely associate in acidic media. Additionally, visual traits of the polymer (P(VDC-co-AN)) were investigated by employing Computer Vision and Image Processing (CVIP) techniques on Scanning Electron Microscopy (SEM) images captured at resolutions ×50, ×200 and ×500. Several visual traits, such as intricate patterns, surface morphology, texture/roughness, particle area distribution ( D A ), directionality ( D P ), mean average particle area ( μ a v g ) and mean average particle standard deviation ( σ a v g ), were investigated on the polymer’s purest form. This collective study facilitates the researches to explore the pure form of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN )) in both chemical and visual perspective.


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