tructure and local order of lyotropic cholesteric calamitic phases: The effect of the chiral molecul

Autor(es)

Santos, O. R. ^[1] ; Reis, D. ^[2] ; Oliveira-Filho, A. G. ^[2] ; Oliveira, C. L. P. ^[2] ; Figueiredo Neto, A. M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Tecnol Fed Parana, Campus Campo Mourao, BR-87301006 Campo Mourao, Parana - Brazil

^[2] Univ Sao Paulo, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MOLECULAR LIQUIDS; v. 349, MAR 1 2022.
• Citações Web of Science: 0

Resumo

We investigate a lyotropic mixture presenting in the calamitic nematic phase (N-C) and its corresponding calamitic cholesteric phase (Ch(C)), where a small amount of the chiral agent (brucine sulfate) was added. Different experimental techniques (polarized optical microscopy and laser conoscopy) were used to characterize the phases. The main technique employed in the analysis of the structure and local ordering at nanoscale is the Small-Angle X-ray Scattering, where advanced modeling analysis were applied. The lyotropic nematic mixtures was composed of potassium laurate/potassium sulfate/dodecanol/water and the cholesteric phases were obtained from these mixtures, by adding the chiral molecule, brucine sulfate. From an advanced modeling analysis, we show that the micellar overall shape is not modified by the doping with brucine. However, the presence of the brucine between micelles in the Ch(C) phase imposes a higher correlation between micelles along the direction of the pseudo-lamellar ordering. Finally, the order parameter < P2 > was calculated and these values for the phases N-C and Ch(C) are 0.8133(6) and 0.747(2), respectively, indicating a slightly higher orientational ordering in the N-C phase. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/50983-3 - INCT 2014: fluidos complexos
• Beneficiário: Antonio Martins Figueiredo Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/24531-3 - Propriedades estruturais e biofísicas de lipoproteínas nativa e modificada
• Beneficiário: Antonio Martins Figueiredo Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático