Alkylated cage silsesquioxanes: a comprehensive study of thermal properties and self-assembled structure

RSC Advances ◽  
2014 ◽  
Vol 4 (66) ◽  
pp. 34981-34986 ◽  
Author(s):  
Lei Wang ◽  
Yoshihito Ishida ◽  
Rina Maeda ◽  
Masatoshi Tokita ◽  
Teruaki Hayakawa
Keyword(s):  
Thermal Properties ◽  
Chain Length ◽  
Long Range ◽  
Aliphatic Chain ◽  
Lamellar Structures ◽  
Self Assembled ◽  
Comprehensive Study

Long-range straight ordered lamellar structures with controllable feature sizes at sub-10 nm scale are created by thoroughly choosing the aliphatic chain length and branch numbers of alkylated cage silsesquioxane.

A comprehensive study of substituent effects on poly(dibenzofulvene)s

2017 ◽  
Vol 41 (2) ◽  
pp. 512-520 ◽  
Author(s):  
Michael Y. Wong ◽  
Louis M. Leung
Keyword(s):  
Thermal Properties ◽  
Substituent Effects ◽  
Comprehensive Study

Comparison of absorption, emission, electrochemistry and thermal properties across 14 poly(DBF)s.

Suppression of Radical-Induced Lipid Peroxidation in a Model System by Alkyl Esters of Cinnamate Quaternary Ammonium Salts

2001 ◽  
Vol 56 (9-10) ◽  
pp. 878-885 ◽  
Author(s):  
Anna Krasowska ◽  
Maria Stasiuk ◽  
Malgorzata Oswiecimska ◽  
Arkadiusz Kozubek ◽  
Malgorzata Bien ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Chain Length ◽  
Alkyl Chain ◽  
Quaternary Ammonium Salts ◽  
Alkyl Chain Length ◽  
Ammonium Salts ◽  
Yeast Cells ◽  
Phenolic Antioxidants ◽  
Lipid Phase ◽  
Aliphatic Chain

AbstractThree new groups of phenolic antioxidants, quaternary ammonium salts with a phenol ring and alkyl chains of different length (pyrrolidine ethyl esters of 3,5-di-t-butyl-4-hydroxydihydrocinnamic acid n-alkoxymethylchlorides (PYE-n) or n-alkylbromides (PYA-n) and 2-dimethylaminoethyl ester n-alkylbromides (PPA-n), were synthesized. Some of them were previously found to efficiently protect yeast cells against oxidants and to inhibit the production of thiobarbituric acid-reactive substances in whole yeast cells and in isolated membrane lipids. The new antioxidants (at 1-100 μm) abolished or diminished peroxidation of oliwe oil emulsions caused by the OH•-producing Fe2+ and RO• and ROO•-producing tertbutylhydroperoxide (TBHP) and the azo compounds 2,2′-azobis-(amidinopropane)dihydronitrile (AAPH) and 1,1′-azobis-(1-cyclohexanecarbonitrile) (ACHN): all present at 10 mᴍ . The efficiency of individual both antioxidants was examined in relation to the type of lipid peroxidation inducer, the site of antioxidant incorporation into the emulsion lipid phase, the length of the alkyl chain, and the maximum concentration of effective antioxidant monomers given by its critical micelle concentration. PYA-n class compounds were highly efficient against all peroxidation inducers and their efficiency did not depend on the position of their molecules in the lipid phase and/or on the aliphatic chain length. In contrast, the efficiency of PYE-n and PPA-n class compounds depended both on the type of oxidant and on the length of their aliphatic chain. Their potency against Fe2+ and ACHN increased with increasing alkyl chain length whereas with AAPH it dropped with increasing alkyl chain length. A similar pattern was found with the action of PYE-n against TBHP whereas in the PPA-n group an extending alkyl chain reduced the anti-TBHP efficiency. These relationships may not be entirely straightforward and other factors (chemical nature of each compound, its possible interaction with fluorescent probes used for diagnostics, etc.) may play a considerable and not yet quite clear role. PPA-n class antioxidants have the lowest critical micelle concentration, which may limit their efficiency. Nevertheless, these phenolic antioxidants can be conveniently employed as highly efficient inhibitors of lipid peroxidation.

The effect of aliphatic chain length on thermal properties of poly(alkylene dicarboxylate)s

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Corrado Berti ◽  
Annamaria Celli ◽  
Paola Marchese ◽  
Elisabetta Marianucci ◽  
Giancarlo Barbiroli ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Three Dimensional ◽  
The Other ◽  
Aliphatic Chain ◽  
Melting Temperatures ◽  
Avrami Analysis ◽  
Isothermal Analysis ◽  
Dimensional Growth ◽  
Crystallizing Polymers ◽  
Crystalline Forms

AbstractSome poly(alkylene dicarboxylate)s, derived from ethanediol or 1,4- butanediol and different diacids, have been synthesized and analyzed by DSC to determine the correlations existing between the thermal properties and the length of the aliphatic chain. The polymers show crystallization and melting temperatures and enthalpies which increase as the polymethylene segments lengthen, due to the formation of more stable crystals. The samples derived from ethanediol are peculiar; they show reorganization processes during the melting and the melting temperatures are notably higher with respect to those of the other polyesters. This behavior is discussed. Isothermal analysis highlights that poly(alkylene dicarboxylate)s are fast crystallizing polymers. The Avrami analysis suggests a crystallization mechanism characterized by heterogeneous nucleation and three dimensional growth; secondary crystallizations is present only in the samples characterized by short -(CH2)- sequences, due to the reorganization of less perfect crystalline forms. A comparative study between the crystallization rates as a function of the undercooling is reported.

Alkanethiol Adsorption on Platinum: Chain Length Effects on the Quality of Self-Assembled Monolayers

2011 ◽  
Vol 115 (36) ◽  
pp. 17788-17798 ◽  
Author(s):  
María Alejandra Floridia Addato ◽  
Aldo A. Rubert ◽  
Guillermo A. Benítez ◽  
Mariano H. Fonticelli ◽  
Javier Carrasco ◽  
...  
Keyword(s):  
Chain Length ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Platinum Chain ◽  
Length Effects

Self-Assembled DNA Photonic Wire for Long-Range Energy Transfer

2008 ◽  
Vol 130 (47) ◽  
pp. 15889-15895 ◽  
Author(s):  
Jonas K. Hannestad ◽  
Peter Sandin ◽  
Bo Albinsson
Keyword(s):  
Energy Transfer ◽  
Long Range ◽  
Self Assembled ◽  
Photonic Wire

scholarly journals X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

2012 ◽  
Vol 3 ◽  
pp. 12-24 ◽  
Author(s):  
Hicham Hamoudi ◽  
Ping Kao ◽  
Alexei Nefedov ◽  
David L Allara ◽  
Michael Zharnikov
Keyword(s):  
Chain Length ◽  
Photoelectron Spectroscopy ◽  
Self Assembled Monolayers ◽  
Phenylene Ethynylene ◽  
X Ray ◽  
Molecular Length ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Gold Thiolate

Self-assembled monolayers (SAMs) of nitrile-substituted oligo(phenylene ethynylene) thiols (NC-OPEn) with a variable chain length n (n ranging from one to three structural units) on Au(111) were studied by synchrotron-based high-resolution X-ray photoelectron spectroscopy and near-edge absorption fine-structure spectroscopy. The experimental data suggest that the NC-OPEn molecules form well-defined SAMs on Au(111), with all the molecules bound to the substrate through the gold–thiolate anchor and the nitrile tail groups located at the SAM–ambient interface. The packing density in these SAMs was found to be close to that of alkanethiolate monolayers on Au(111), independent of the chain length. Similar behavior was found for the molecular inclination, with an average tilt angle of ~33–36° for all the target systems. In contrast, the average twist of the OPEn backbone (planar conformation) was found to depend on the molecular length, being close to 45° for the films comprising the short OPE chains and ~53.5° for the long chains. Analysis of the data suggests that the attachment of the nitrile moiety, which served as a spectroscopic marker group, to the OPEn backbone did not significantly affect the molecular orientation in the SAMs.

InGaZnO Thin-Film Transistors Modified by Self-Assembled Monolayer With Different Alkyl Chain Length

2015 ◽  
Vol 36 (7) ◽  
pp. 687-689 ◽  
Author(s):  
Peng Xiao ◽  
Linfeng Lan ◽  
Ting Dong ◽  
Zhenguo Lin ◽  
Sheng Sun ◽  
...  
Keyword(s):  
Thin Film ◽  
Chain Length ◽  
Thin Film Transistors ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Self Assembled Monolayer ◽  
Self Assembled
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