Adsorption of Weak Polyelectrolytes to an Oppositely Charged Langmuir Film:  Change in the Conformation of the Adsorbed Molecules and Saturation of the Ionization Degree

2004 ◽  
Vol 37 (23) ◽  
pp. 8715-8720 ◽  
Author(s):  
Laurianne Vagharchakian ◽  
Bernard Desbat ◽  
Sylvie Hénon

Langmuir ◽  
2011 ◽  
Vol 27 (15) ◽  
pp. 9270-9276 ◽  
Author(s):  
Amin Sadeghpour ◽  
Emek Seyrek ◽  
István Szilágyi ◽  
José Hierrezuelo ◽  
Michal Borkovec


Polymer ◽  
2019 ◽  
Vol 172 ◽  
pp. 178-186
Author(s):  
Hoofar Sadadi ◽  
Mohammad Imani ◽  
Mohammad Atai ◽  
Bernhard A. Wolf ◽  
Sebastian Seiffert




Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 898 ◽  
Author(s):  
Boris M. Okrugin ◽  
Ralf P. Richter ◽  
Frans A. M. Leermakers ◽  
Igor M. Neelov ◽  
Ekaterina B. Zhulina ◽  
...  

End-grafting of polyelectrolyte chains to conducting substrates offers an opportunity to fabricate electro-responsive surfaces capable of changing their physical/chemical properties (adhesion, wettability) in response to applied electrical voltage. We use a self-consistent field numerical approach to compare the equilibrium properties of tethered strong and weak (pH-sensitive) polyelectrolytes to applied electrical field in both salt-free and salt-containing solutions. We demonstrate that both strong and weak polyelectrolyte brushes exhibit segregation of polyions in two populations if the surface is oppositely charged with respect to the brush. This segregation gives rise to complex patterns in the dependence of the brush thickness on salt concentration. We demonstrate that adjustable ionization of weak polyelectrolytes weakens their conformational response in terms of the dependence of brush thickness on the amplitude of the applied voltage.



Somatechnics ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 58-83
Author(s):  
Akkadia Ford

Cinema provides ‘privileged access’ ( Zubrycki 2011 ) into trans lives, recording and revealing private life experiences and moments that might never be seen, nor heard and after the time had passed, only present in memory and body for the individuals involved. Film, a temporal medium, creates theoretical issues, both in the presentation and representation of the trans body and for audiences in viewing the images. Specific narrative, stylistic and editing techniques including temporal disjunctions, may also give audiences a distorted view of trans bodily narratives that encompass a lifetime. Twenty first century cinema is simultaneously creating and erasing the somatechnical potentialities of trans. This article will explore temporal techniques in relation to recent trans cinema, comparing how three different filmmakers handle trans narratives. Drawing upon recent films including the Trans New Wave ( Ford 2014 , 2016a , 2016b ), such as the experimental animated autoethnographic short film Change Over Time (Ewan Duarte, United States, 2013), in tandem with the feature film 52 Tuesdays (Sophia Hyde, Australia, 2013), I will analyse the films as texts which show how filmmakers utilise temporality as a narrative and stylistic technique in cinematic trans narratives. These are texts where cinematic technologies converge with trans embodiment in ways that are constitutive of participants and audiences' understanding of trans lives. This analysis will be contrasted with the use of temporal displacement as a cinematic trope of negative affect, disembodiment and societal disjunction in the feature film Predestination (The Spierig Brothers, Australia, 2014), providing a further basis for scholarly critique of cinematic somatechnics in relation to the trans body.



2018 ◽  
Vol 138 (3) ◽  
pp. 236-241 ◽  
Author(s):  
Mio Tsuruoka ◽  
Manabu Tanaka ◽  
Yoshihiro Okuno


2019 ◽  
Author(s):  
Jonas Landsgesell ◽  
Oleg Rud ◽  
Pascal Hebbeker ◽  
Raju Lunkad ◽  
Peter Košovan ◽  
...  

We introduce the grand-reaction method for coarse-grained simulations of acid-base equilibria in a system coupled to a reservoir at a given pH and concentration of added salt. It can be viewed as an extension of the constant-pH method and the reaction ensemble, combining explicit simulations of reactions within the system, and grand-canonical exchange of particles with the reservoir. Unlike the previously introduced methods, the grand-reaction method is applicable to acid-base equilibria in the whole pH range because it avoids known artifacts. However, the method is more general, and can be used for simulations of any reactive system coupled to a reservoir of a known composition. To demonstrate the advantages of the grand-reaction method, we simulated a model system: A solution of weak polyelectrolytes in equilibrium with a buffer solution. By carefully accounting for the exchange of all constituents, the method ensures that all chemical potentials are equal in the system and in the multi-component reservoir. Thus, the grand-reaction method is able to predict non-monotonic swelling of weak polyelectrolytes as a function of pH, that has been known from mean-field predictions and from experiments but has never been observed in coarse-grained simulations. Finally, we outline possible extensions and further generalizations of the method, and provide a set of guidelines to enable safe usage of the method by a broad community of users.<br><br>



1987 ◽  
Vol 52 (3) ◽  
pp. 572-581 ◽  
Author(s):  
Miroslav M. Kopečni ◽  
Slobodan K. Milonjic ◽  
Wladyslaw Rudzinski ◽  
Jacek Jagiello

Adsorption isotherms of three adsorbates on the solid beads obtained from colloidal silica were determined by means of gas chromatography at low surface coverages, when lateral interactions between the adsorbed molecules are negligible. The influence of thermal pretreatment on the adsorption properties of the solids was investigated in the temperature range from 343 to 423 K, while the solids were heated between 523 K and 1 223 K. The thermodynamic parameters of adsorption have been determined and used to discuss the adsorbate-adsorbent interactions.



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