Effect of structural isomerism and polymer end group on the pH-stability of hydrogen-bonded multilayers

Date

2011-09-15

Author

Erel Göktepe, İrem
Demirel, A. Levent

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

183
views

0
downloads

Association of tannic acid (TA) with structurally isomeric poly(N-isopropylacrylamide) (PNIPAM) and poly(2-isopropyl-2-oxazoline) (PIPOX) has been examined at surfaces to understand the effect of different molecular arrangements in a polymer repeating unit of structural isomers on the construction and pH-stability of hydrogen-bonded multilayers. Films were fabricated using layer-by-layer (LbL) technique through hydrogen-bonding interactions primarily between carbonyl groups of neutral polymers and hydroxyl groups of TA molecules at pH 2. PIPOX and TA formed thinner and more stable films in the pH scale with a critical dissolution pH of 9 when compared to films of PNIPAM and TA with a critical pH of 8. The differences in the thickness and pH-stability were due to different conformational behavior of PNIPAM and PIPOX in water which affects the accessibility of carbonyl groups for participation in the hydrogen bonding and the number of binding sites between the polymer pairs. Addition of electrostatic interactions by introducing amino groups only at the PIPOX chain end shifted the critical dissolution pH to higher values and resulted in gradual dissolution of the films in a wide pH range of 9-12. Such films hold promise for use in biomedical field due to biocompatibility and lower critical solution temperature (LCST) behavior at near physiological temperature of PNIPAM and PIPOX together with the pH-response of the hydrogen-bonded films.

Subject Keywords

Layer-By-Layer Technique, Hydrogen-Bonding, Multilayers, Structural Isomers, Polymer End-Group, Ph-Responsive

URI

https://hdl.handle.net/11511/42241

Journal

JOURNAL OF COLLOID AND INTERFACE SCIENCE

DOI

https://doi.org/10.1016/j.jcis.2011.05.033

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Effect of Alkyl Derivatization on Several Properties of N-Halamine Antimicrobial Siloxane Coatings Kocer, Hasan B.; Akdağ, Akın; Ren, Xuehong; Broughton, R. M.; Worley, S. D.; Huang, T. S. (American Chemical Society (ACS), 2008-10-01) Variation of alkyl substitution at position 5 on the hydantoin ring of a series of N-halamine siloxane derivatives has been employed to better understand the biocidal activities of these compounds for use in preparing antimicrobial coatings. The alkyl derivatization of the hydantoin ring at its 5 position, while an essentially constant chlorine loading is maintained at the I position, has shown that there is little dependence of the antimicrobial efficacy against Escherichia coli O157:H7 on the alkyl chain ...
Effect of fluorine substituted benzothiadiazole on electro-optical properties of donor-acceptor-donor type monomers and their polymers Çakal, Deniz; Önal, Ahmet Muhtar (Elsevier BV, 2020-11-01) A series of trimeric monomers bearing thiophene donor units and fluorinated analogues of benzothiadiazole acceptor units was synthesized via donor-acceptor-donor approach and polymerized electrochemically in order to investigate the effect of fluorine atom on electro-optical properties of both monomers and their corresponding polymers. All monomers exhibited solvatochromic and fluorescent properties. The introduction of fluorine atom into the conjugated backbone increased the oxidation potentials. Upon movi...
Effect of Presoaked Expanded Perlite Aggregate on the Dimensional Stability and Mechanical Properties of Engineered Cementitious Composites KESKİN, SÜLEYMAN BAHADIR; Sulaiman, Kamaran; Sahmaran, Mustafa; Yaman, İsmail Özgür (American Society of Civil Engineers (ASCE), 2013-06-01) This paper reports on an investigation of the use of expanded perlite aggregate as saturated lightweight aggregate (LWA) with respect to the mechanical and dimensional stability properties of engineered cemetitious composites (ECC). Expanded perlite aggregate was soaked in water for 24 h before its use in ECC, and replaced 10, 20, and 30% of the aggregate that was used in ECC production. The mixture proportion of a standard ECC mixture with properties that have been extensively reported in the literature is...
Effect of impact modifier on the properties of poly (ethylene terephthalate)-organoclay nanocomposites Yılmazer, Ülkü; Alyamac, Elif (2006-11-30) The effects of component concentrations and addition order of the components, on the final properties of ternary nanocomposites composed of amorphous poly (ethylene terephthalate) matrix, organically modified clay, and an ethylene / methyl acrylate / glycidyl methacrylate (E-MAGMA) terpolymer were studied. All formulations were prepared by melt compounding of the components with a two-step mixing procedure in a corotating twin-screw extruder. Considering the X-Ray Diffraction, SEM, impact and strain at brea...
Effect of Conjugated Core Building Block Dibenzo[a,c]phenazine Unit on pi-Conjugated Electrochromic Polymers: Red-Shifted Absorption Unver, Elif Kose; Tarkuc, Simge; Udum, Yasemin Arslan; Tanyeli, Cihangir; Toppare, Levent Kamil (2010-04-15) A comparative investigation was undertaken for the electrosynthesis and electrochemical properties of three different electroactive polymers having a conjugated core building block, dibenzo[a,c]phenazine. A series of monomers has been synthesized as regards to thiophene based units; thiophene, 3-hexyl thiophene, and 3,4-ethylenedioxythiophene. The effects of different donor substituents on the polymers' electrochemical properties were examined by cyclic voltammetry. Introducing highly electron-donating (eth...

Citation Formats

İ. Erel Göktepe and A. L. Demirel, “Effect of structural isomerism and polymer end group on the pH-stability of hydrogen-bonded multilayers,” JOURNAL OF COLLOID AND INTERFACE SCIENCE, pp. 477–482, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/42241.