Permeability studies on heterogeneous polymer films

1968 ◽  
Vol 12 (12) ◽  
pp. 2649-2667 ◽  
Author(s):  
Clarke M. Peterson
Keyword(s):  
Polymer Films ◽  
Heterogeneous Polymer ◽  
Permeability Studies

scholarly journals Electropolymerization of N,N'-Diphenylguanidine in Non-Aqueous Aprotic Solvents and Alcohols

2020 ◽  
Vol 65 (1) ◽  
pp. 139-147
Author(s):  
László Kiss ◽  
Ferenc Kovács ◽  
Sándor Kunsági-Máté
Keyword(s):  
Cyclic Voltammetry ◽  
Dimethyl Sulfoxide ◽  
Benzyl Alcohol ◽  
Polymer Films ◽  
Platinum Electrode ◽  
Anodic Peak ◽  
Dimethyl Formamide ◽  
Aprotic Solvents ◽  
Permeability Studies ◽  
Voltammetric Peak

Electrooxidation of N,N’-diphenylguanidine (1,3-diphenylguanidine) was investigated in aprotic (acetonitrile, acetone, dimethyl sulfoxide, dimethyl formamide, propyleneoxide, nitromethane) and alcoholic (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, benzyl alcohol) non-aqueous solvents at platinum electrode with cyclic voltammetry. Its concentration was 5 mM in most cases. In acetonitrile and acetone a sharp voltammetric peak appeared around 1 V vs. reference and currents measured in the subsequent scans showed that the electrode fouled quickly. In dimethyl formamide, the anodic peak heights decreased slowly in the subsequent scans but in dimethyl sulfoxide weak deactivation could be observed both in smaller and in higher concentration. In alcohols, continuous deactivation could be also observed during electrooxidation of N,N’-diphenylguanidine. The permeability studies showed that the structure of the formed polymer films varied significantly according to the solvent used for electrodeposition.

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

Is the chain dynamics in thin polymer films isotropic ?

2000 ◽  
Vol 10 (PR7) ◽  
pp. Pr7-233-Pr7-237 ◽  
Author(s):  
S. Rivillon ◽  
P. Auroy ◽  
B. Deloche
Keyword(s):  
Polymer Films ◽  
Thin Polymer Films ◽  
Chain Dynamics ◽  
Thin Polymer
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