scholarly journals Influence of Side Chain Length on the Self-Assembly of Hairy-Rod Poly(9,9-dialkylfluorene)s in the Poor Solvent Methylcyclohexane

2007 ◽  
Vol 40 (26) ◽  
pp. 9398-9405 ◽  
Author(s):  
M. Knaapila ◽  
F. B. Dias ◽  
V. M. Garamus ◽  
L. Almásy ◽  
M. Torkkeli ◽  
...  
2017 ◽  
Vol 53 (93) ◽  
pp. 12572-12575 ◽  
Author(s):  
Liu-Pan Yang ◽  
Fei Jia ◽  
Fangfang Pan ◽  
Zhi-Sheng Pan ◽  
Kari Rissanen ◽  
...  

The side-chain length of oxatub[4]arenes was shown to affect its conformational interconversion, molecular recognition and macroscopic self-assembly behavior.


2021 ◽  
Author(s):  
Sayak Subhra Panda ◽  
John D. Tovar

Peptidic sequences when conjugated to π-electronic groups form self-assembled networks of π-electron pathways. These materials hold promise for bio-interfacing charge transporting applications because of their aqueous processability and compatibility. In this work, we incorporated diketopyrrolopyrrole (DPP), a well-established π-core for organic electronic applications, within the peptidic sequence. We embedded different numbers of thiophene rings (2 and 3) on both sides of the DPP to alter the length of the π-cores. We also varied the length of the N-alkyl side chains (methyl, butyl, hexyl) attached to the DPP core. These variations allowed us to explicitly study the effect of π-core and N-alkyl side-chain length on photophysical properties and morphology of the resulting nanomaterials. All of these molecules formed H-type aggregates in the assembled state. Longer π-cores have relatively red-shifted absorption maxima whereas the N-alkyl variation did not present significant photophysical changes.


2020 ◽  
Vol 27 (9) ◽  
pp. 923-929
Author(s):  
Gaurav Pandey ◽  
Prem Prakash Das ◽  
Vibin Ramakrishnan

Background: RADA-4 (Ac-RADARADARADARADA-NH2) is the most extensively studied and marketed self-assembling peptide, forming hydrogel, used to create defined threedimensional microenvironments for cell culture applications. Objectives: In this work, we use various biophysical techniques to investigate the length dependency of RADA aggregation and assembly. Methods: We synthesized a series of RADA-N peptides, N ranging from 1 to 4, resulting in four peptides having 4, 8, 12, and 16 amino acids in their sequence. Through a combination of various biophysical methods including thioflavin T fluorescence assay, static right angle light scattering assay, Dynamic Light Scattering (DLS), electron microscopy, CD, and IR spectroscopy, we have examined the role of chain-length on the self-assembly of RADA peptide. Results: Our observations show that the aggregation of ionic, charge-complementary RADA motifcontaining peptides is length-dependent, with N less than 3 are not forming spontaneous selfassemblies. Conclusion: The six biophysical experiments discussed in this paper validate the significance of chain-length on the epitaxial growth of RADA peptide self-assembly.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1789
Author(s):  
Dmitry Tolmachev ◽  
George Mamistvalov ◽  
Natalia Lukasheva ◽  
Sergey Larin ◽  
Mikko Karttunen

We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration.


1998 ◽  
Vol 39 (2) ◽  
pp. 302-312 ◽  
Author(s):  
Ian J. Martins ◽  
Catherine Vilchèze ◽  
B-C. Mortimer ◽  
Robert Bittman ◽  
Trevor G. Redgrave

2021 ◽  
pp. 116251
Author(s):  
M.A. Olea-Amezcua ◽  
J.E. Castellanos-Águila ◽  
H. HernÁndez-Cocoletzi ◽  
E. Ferreira ◽  
M. Trejo-Durán ◽  
...  

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