New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction
Amino acid-based surfactants were used as the main surfactants to prepare new lyotropic mixtures presenting three nematic phases. One of them is biaxial (NB), and the two others are uniaxial, discotic (ND) and calamitic (NC). These surfactants were the non-chiral molecules, potassium N-dodecanoyl-...
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2014-05-01
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| author | Erol Akpinar Dennys Reis Muhammet Yildirim Antônio Martins Figueiredo Neto |
| author_facet | Erol Akpinar Dennys Reis Muhammet Yildirim Antônio Martins Figueiredo Neto |
| author_sort | Erol Akpinar |
| collection | DOAJ |
| description | Amino acid-based surfactants were used as the main surfactants to prepare new lyotropic mixtures presenting three nematic phases. One of them is biaxial (NB), and the two others are uniaxial, discotic (ND) and calamitic (NC). These surfactants were the non-chiral molecules, potassium N-dodecanoyl-DL-alaninate (DL-KDDA), potassium N-dodecanoyl-DL-serinate (DL-KDDS), disodium N-dodecanoyl-DL-aspartate (DL-NaDDAs) and potassium N-dodecanoyl-glycinate (KDDGly). Measurements of the optical birefringences and X-ray diffraction analysis were used to characterize the nematic phases and phase transitions. Mixtures with DL-KDDS exhibited the largest biaxial phase domain (~9 °C) with respect to the other mixtures in this study. The results obtained with the KDDGly mixture showed that the existence of hydrogen bonding between the head groups of the surfactant molecules seems to hinder the orientation of the micelles under the action of an external magnetic field. |
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| id | doaj.art-cb20a11eb5c04c7abe0d6675d9be4b83 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-04-12T10:25:17Z |
| publishDate | 2014-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-cb20a11eb5c04c7abe0d6675d9be4b832022-12-22T03:37:00ZengMDPI AGMaterials1996-19442014-05-01764132414710.3390/ma7064132ma7064132New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray DiffractionErol Akpinar0Dennys Reis1Muhammet Yildirim2Antônio Martins Figueiredo Neto3Department of Chemistry, Arts and Sciences Faculty, Abant Izzet Baysal University, Bolu 14280, TurkeyInstituto de Física, Universidade de São Paulo, Caixa Postal 66318, São Paulo, SP 05314-970, BrazilDepartment of Chemistry, Arts and Sciences Faculty, Abant Izzet Baysal University, Bolu 14280, TurkeyInstituto de Física, Universidade de São Paulo, Caixa Postal 66318, São Paulo, SP 05314-970, BrazilAmino acid-based surfactants were used as the main surfactants to prepare new lyotropic mixtures presenting three nematic phases. One of them is biaxial (NB), and the two others are uniaxial, discotic (ND) and calamitic (NC). These surfactants were the non-chiral molecules, potassium N-dodecanoyl-DL-alaninate (DL-KDDA), potassium N-dodecanoyl-DL-serinate (DL-KDDS), disodium N-dodecanoyl-DL-aspartate (DL-NaDDAs) and potassium N-dodecanoyl-glycinate (KDDGly). Measurements of the optical birefringences and X-ray diffraction analysis were used to characterize the nematic phases and phase transitions. Mixtures with DL-KDDS exhibited the largest biaxial phase domain (~9 °C) with respect to the other mixtures in this study. The results obtained with the KDDGly mixture showed that the existence of hydrogen bonding between the head groups of the surfactant molecules seems to hinder the orientation of the micelles under the action of an external magnetic field.http://www.mdpi.com/1996-1944/7/6/4132biaxial nematicphase transitionsbirefringencelaser conoscopystructurehydrogen bondingX-ray diffraction |
| spellingShingle | Erol Akpinar Dennys Reis Muhammet Yildirim Antônio Martins Figueiredo Neto New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction Materials biaxial nematic phase transitions birefringence laser conoscopy structure hydrogen bonding X-ray diffraction |
| title | New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction |
| title_full | New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction |
| title_fullStr | New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction |
| title_full_unstemmed | New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction |
| title_short | New Lyotropic Mixtures with Non-Chiral N-Acylamino Acid Surfactants Presenting the Biaxial Nematic Phase Investigated by Laser Conoscopy, Polarized Optical Microscopy and X-ray Diffraction |
| title_sort | new lyotropic mixtures with non chiral n acylamino acid surfactants presenting the biaxial nematic phase investigated by laser conoscopy polarized optical microscopy and x ray diffraction |
| topic | biaxial nematic phase transitions birefringence laser conoscopy structure hydrogen bonding X-ray diffraction |
| url | http://www.mdpi.com/1996-1944/7/6/4132 |
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