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Relevant bibliographies by topics / Mesogenic systems

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Academic literature on the topic 'Mesogenic systems'

Author: Grafiati

Published: 18 May 2024

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Journal articles on the topic "Mesogenic systems"

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Chao, C. Y., X. Li, and C. K. Ober. "Directing self-assembly in macromolecular systems: Hydrogen bonding in ordered polymers." Pure and Applied Chemistry 76, no. 7-8 (January 1, 2004): 1337–43. http://dx.doi.org/10.1351/pac200476071337.

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Hydrogen-bonded side-chain liquid-crystalline block copolymers (SCLCBCPs) containing block segments with proton donors were combined with functionalized mesogenic pendent groups. Studies of a wide range of mesogen and polymer combinations were carried out to study the relationship between morphology and mesophase behavior. The thermal behaviors of the resulting self-assembled microstructures were also examined. A model of the assembly process leading to mesogenic group organization corresponding to different compositions was proposed.

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Vora, R. A., and S. J. Rajput. "Binary Mesogenic Systems Comprised of Ester Mesogens and Non-Mesogens." Molecular Crystals and Liquid Crystals 209, no. 1 (December 1991): 265–77. http://dx.doi.org/10.1080/00268949108036201.

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Koßmehl, Gerhard, and Jürgen Bahr. "Liquid Crystalline Azomethines and Polyazomethines Containing Azobenzene and Stilbene Units." Zeitschrift für Naturforschung B 46, no. 2 (February 1, 1991): 245–54. http://dx.doi.org/10.1515/znb-1991-0219.

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Azobenzene and stilbene derivatives with azomethine and ester groups and polymers of corresponding structures with mesogens possessing three to four aromatic systems in their mesogenic units have been synthesized, characterized and studied for their liquid crystalline properties by DSC measurements and observation by polarizing microscopy.

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Mirnaya, T. A., G. G. Yaremchuk, and S. V. Volkov. "Phase Diagrams of Binary Alkanoate Systems with Common Cation: Potassium Isobutyrate-Propionate, and Sodium Butyrate-Isobutyrate." Zeitschrift für Naturforschung A 51, no. 8 (August 1, 1996): 957–59. http://dx.doi.org/10.1515/zna-1996-0811.

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Abstract The phase diagrams of the binary mixtures of mesogenic potassium isobutyrate with non-mesogenic potassium propionate and mesogenic sodium butyrate with non-mesogenic sodium isobutyrate have been investigated by differential thermal analysis and hot stage polarization microscopy. Both systems have one eutectic and one metatectic phase equilibriums. Pecularities of liquid crystal formation in binary alkanoate systems with common alkali metal cation are discussed and compared with those of systems with common anion.

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Dolden, J. G., and P. T. Alder. "The Mesogenic Index: An Empirical Method for Predicting Polymeric Liquid Crystallinity." High Performance Polymers 10, no. 3 (September 1998): 249–72. http://dx.doi.org/10.1088/0954-0083/10/3/004.

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An empirical method for predicting the chemical compositions of random or partially ordered copolymers that exhibit mesophases was devised by the authors in 1989, while working on liquid crystal copolymer synthesis for BP Chemicals. A brief description of the method and its application to the chemical synthesis of amorphous thermotropic polyamides was given by the authors in a previous paper. Thermotropic polyimides were also synthesized by the authors as a result of the use of the predictive method. Subsequently, the method has been updated and applied to polycarbonates and polyimides. The new approach has been termed ‘the mesogenic index’ (MI) and has successfully been applied to 23 copolymer systems in which the critical compositions for mesophase formation have been established by means of varying constituent monomer concentrations. It is also consistent in predicting liquid crystalline behaviour in several hundred main-chain polymer systems containing amide, ester, carbonate, ether and urethane groups. It is inherent in the MI system that the mesogenic length is defined in terms of the number of monomer units for a given polymer class. From published work in the literature, it was first established that ester and amide groups need at least two and three aromatic rings in the mesogen respectively. Using these values to define mesogen length in polyester and polyamide copolymers, the condition MI > 10 has been determined for mesophase formation. This rule has been applied to other linking groups, such as carbonate or imide, with the surprising result that the corresponding mesogen lengths for these condensation polymers are simple numbers. Moreover, the rule has been applied successfully to mixed systems, by simply averaging the contributions of the different groups to the mesogen length in strictly molar proportions. The mesogenic index is based upon summing functional group contributions towards rigidity and/or resonance stabilization of the mesogen. To the best of our knowledge, this is the first simple method to be published that successfully correlates chemical composition with mesophase formation.

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Mirnaya, T. A., G. G. Yaremchuk, and S. V. Volkov. "Phase Diagrams of Binary Systems of Some Alkali Iso–Butyrates with One Mesogenic Component." Zeitschrift für Naturforschung A 50, no. 9 (September 1, 1995): 893–96. http://dx.doi.org/10.1515/zna-1995-0917.

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Abstract The phase diagrams of the binary mixtures of mesogenic potassium iso-butyrate with non-mesogenic lithium-, sodium-, and caesium iso-butyrate have been investigated by differential thermal analysis and hot stage polarization microscopy. The temperature and concentration ranges of liquid crystal formation have been established. Sodium and caesium iso-butyrate have been found to possess latent mesogenic properties.

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Mirnaya, T. A., Y. V. Bereznitski, and S. V. Volkov. "Liquid Crystals and Glasses in Binary Systems from Sodium and Alkali-Earth Metal Butyrates." Zeitschrift für Naturforschung A 51, no. 7 (July 1, 1996): 867–70. http://dx.doi.org/10.1515/zna-1996-0711.

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Abstract The temperature and composition ranges of liquid crystal and glass formation have been established for the binary mixtures of mesogenic sodium butyrate with non-mesogenic magnesium, calcium and strontium butyrates by means of differential thermal analysis and hot stage polarization microscopy. The formation of a vitreous optically anisotropic mesophase has been found for binaries of sodium butyrate with calcium and strontium butyrates.

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Krigbaum, William R. "Phase studies of binary mesogenic systems." Faraday Discussions of the Chemical Society 79 (1985): 133. http://dx.doi.org/10.1039/dc9857900133.

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Bubnov, Alexej, Martin Cigl, Deyvid Penkov, Marek Otruba, Damian Pociecha, Hsiu-Hui Chen, and Věra Hamplová. "Design and Self-Assembling Behaviour of Calamitic Reactive Mesogens with Lateral Methyl and Methoxy Substituents and Vinyl Terminal Group." Polymers 13, no. 13 (June 30, 2021): 2156. http://dx.doi.org/10.3390/polym13132156.

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Smart self-organising systems attract considerable attention in the scientific community. In order to control and stabilise the liquid crystalline behaviour, and hence the self-organisation, the polymerisation process can be effectively used. Mesogenic units incorporated into the backbones as functional side chains of weakly cross-linked macromolecules can become orientationally ordered. Several new calamitic reactive mesogens possessing the vinyl terminal group with varying flexible chain lengths and with/without lateral substitution by the methyl (methoxy) groups have been designed and studied. Depending on the molecular structure, namely, the type and position of the lateral substituents, the resulting materials form the nematic, the orthogonal SmA and the tilted SmC phases in a reasonably broad temperature range, and the structure of the mesophases was confirmed by X-ray diffraction experiments. The main objective of this work is to contribute to better understanding of the molecular structure–mesomorphic property relationship for new functional reactive mesogens, aiming at further design of smart self-assembling macromolecular materials for novel sensor systems.

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Li, Qian Yue, Jun Xu, Wen Zheng Zhang, and Peng Li. "Preparation and Characterization of Chiral Cyclosiloxane-Based Liquid-Crystalline Elastomers Bearing Menthyl Groups." Advanced Materials Research 466-467 (February 2012): 445–48. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.445.

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Chiral side-chain liquid-crystalline elastomers (LCEs) IP~IVP containig menthyl groups were synthesized by a one-step hydrosilylation reaction. The chemical structures and LC properties of the monomers and polymers were characterized by use of various experimental techniques. The effect of crosslinking mesogens on mesomorphic properties of the chiral LCEs was studied by swelling experiments. All the samples IP~IVP showed cholesteric mesophase when they were heated and cooled, proved by visual observation and X-ray measurements. The glass transition temperature (Tg) of elastomers increased slightly with increase of crosslinking mesogens in the polymer systems, but mesophase-isotropic phase transition temperature (Ti) decreased slightly, suggesting that the temperature range of mesophase became narrow with increase of crosslinking mesogens for all the elastomers. The maximum reflection bands shift slightly to long wavelength and become broad at the same temperature, indicating that the helical structure is partially disrupted because of both the constraint of chemical crosslinking agents and the different mesogenic units.

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Dissertations / Theses on the topic "Mesogenic systems"

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Haldar, Sripada. "Investigation on some achiral and chiral mesogemic systems by different experimental techniques." Thesis, University of North Bengal, 2013. http://hdl.handle.net/123456789/1481.

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Tamba, Maria Gabriela [Verfasser], W. [Akademischer Betreuer] Weißflog, and R. [Akademischer Betreuer] Zentel. "Design of liquid crystal dimers and trimers : synthesis and characterization of novel systems containing bent-core and calamitic mesogenic units / Maria Gabriela Tamba. Betreuer: W. Weißflog ; R. Zentel." Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2014. http://d-nb.info/1069814741/34.

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Elliott, Alice Margaret Sophie. "The physical structure of a system of mesogenic side chain polymers." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388435.

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Lian, Qing. "Structural investigation of a mesogen-chitosan graft copolymer system." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8598.

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Harwood, Simon M. "Novel chiral thermochromic mesogens derived from cholest-5-en-3#beta#-ol and related systems." Thesis, University of Hull, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327294.

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Thompson, Neil James. "The synthesis and liquid-crystalline properties of metallo-mesogens : copper (II) complexes of #beta#-diketones and ferrocene-containing systems." Thesis, University of Hull, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259771.

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Piovesan, Annie. "Contribution a l'etude de la structure moleculaire de mesogenes thermotropes hautement ordonnes : transitions monocouche-bicouche dans des composes polaires." Clermont-Ferrand 2, 1986. http://www.theses.fr/1986CLF21042.

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Etude de cristaux liquides thermotropes presentant des phases smectiques de type a et b. Etude de l'influence de divers parametres moleculaires sur la stabilite thermique de telles phases. Proposition d'un modele d'organisation des molecules a l'interieur d'une lamelle smectique

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Guo, Chang-yi, and 郭昶邑. "Wide blue phase range observed in simple binary mixture systems containing biphenyl mesogens with 2-octyloxy tail." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/54061303021332896775.

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碩士
大同大學
化學工程學系(所)
104
Four series of simple and rodlike racemic biphenyl mesogens possessing 2-octyloxy tail and different substituents at inner-core position of phenyl ring were easily prepared. In general, cubic BPs can be induced by adding appropriate ratio of chiral additive S811 or ISO(6OBA)2 into these racemic biphenyl mesogens during the heating and cooling processes. Interestingly, BPIII (5-6 K) easily dominates in high chirality condition for the blending mixture composed of mono-substituted biphenyl mesogens and chiral dopant S811. In addition, formation temperature of BPIII is near room temperature (36°C) when compound C6OBiPhI-OH is blend with 35 wt% S811 during the cooling process. Stable BPs with more than 20 K present in the blending mixture system composed of chiral dopant ISO(6OBA)2 and no substituted biphenyl mesogens CnOBiPhI-H or difluoro substituted CnOBiPhI-FF. Notably, the widest temperature range of BP (~34 K) can be induced by adding only 10 wt% chiral dopant ISO(6OBA)2 with high HTP into the biphenyl compound C6OBiPhI-H. The properties of BPs were characterized by POM, DSC and reflection spectra. On the basis of our experimental results and molecular modeling, we demonstrated that the appearance and temperature range of BPs in this simple type of biphenyl mesogen with 2-octyloxy tail are affected by the molecular dipole moment and biaxiality.

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Wu, Zong-Ye, and 吳宗燁. "The effect of functional groups of racemic rodlike Schiff base mesogens on the stabilization of blue phase in binary mixture system." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41890230015479625079.

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碩士
大同大學
化學工程學系(所)
104
Four series of rodlike racemic Schiff base mesogens possessing different alkyl chains and two types of linkage, ester and alkynyl groups were synthesized and applied to induce cubic blue phases (BPs) in simple binary mixture systems. The mesophases of these Schiff base mesogens were confirmed by variable-temperature XRD and the characteristic texture of POM. In general, when chiral additive S811 with the ratio of 20-40 wt% is added into the rodlike racemic Schiff base mesogens possessing hydroxyl group, the temperature range of cubic BPs could be induced more than 20 K. The widest temperature range of cubic BP (35 K) presents in the blending mixture composed of rodlike racemic salicylaldimine-based mesogen OH-TIn possessing alkynyl linkage and 35-40 wt% S811. However, Schiff base mesogens with alkynyl linkage and no hydroxyl group show direct isotropic to chiral nematic transition when equal chiral dopants is added. Interestingly, wide BPs (>30 K) also can be induced by adding chiral additive ISO(6OBA)2 with high HTP into the racemic Schiff base mesogen with ester linkage. Cubic BPI and BPII can be confirmed by reflectance spectra and polarized optical microscopy (POM). The results of reflectance spectra indicate that Schiff base mesogens possessing alkoxy chain exhibit wider BPII range than Schiff base mesogens possessing alkyl chain due to larger super-cooling effect in the binary mixture system containing chiral dopant S811. However, only BPII can be induced in the blending mixture system composed of Schiff base mesogen and ISO(6OBA)2 both on heating and cooling processes. On the basis of our experimental results and molecular modeling, the appearance and temperature range of BPs are affected by the values of biaxiality, the polarizability and dipole moment of geometry.

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Lobo, Nitin Prakash. "NMR Methods For The Study Of Partially Ordered Systems." Thesis, 2012. https://etd.iisc.ac.in/handle/2005/2588.

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The work presented in this thesis has two parts. The first part deals with methodological developments in the area of solid-state NMR, relevant to the study of partially ordered systems. Liquid crystals are best examples of such partially ordered systems and they are easily oriented by the magnetic field used for the NMR study. They provide spectra rich in information useful for the study of structure and dynamic s of the oriented molecule. Dipolar couplings and anisotropic chemical shifts are relatively easy to obtain for these systems. However, the methodologies used for extracting the required information are constantly undergoing change, with newer ideas being used for optimal use of the technique and increasing the sensitivity of the methodology. In this thesis, existing methods used for obtaining dipolar couplings from oriented liquid crystalline samples are examined in detail and conditions for optimal use of the methods are investigated. Different approaches for enhancing the sensitivity of the techniques are also proposed. Estimation of chemical shift anisotropy of carbons for a molecule that is used as a building block for several mesogens has been obtained and its utility for estimating the order parameters of the system have been examined. The second part of the thesis deals with the application of solid state NMR methods to the study of a number of novel liquid crystalline systems and for the estimation of dynamics, order and orientation of the mesogenic molecules in the magnetic field. Chapter-2 deals with a detailed and systematic study to improve the sensitivity of cross-polarization based separated local field (SLF) NMR spectroscopy techniques such as PISEMA(Polarization Inversion Spin Exchange at the Magic Angle) and PDLF(Pro-ton Detected Local Field). The chapter has been further divided into three sections. Section-A describes the optimization procedure for cross-polarization period for reducing zero-frequency peaks in SLF experiments. Polarization Inversion(PI) is one of the important components of PISEMA and plays a crucial role in enhancing the dipolar cross-peaks and suppressing the axial-peaks. Shortening this period has the advantage of less r.f. power input into the system, thus less susceptibility to sample heating. Therefore it is crucial to arrive at the optimum condition for which maximum sensitivity and resolution are obtained. A detailed experimental investigation of the role of the initial po1arization period has been carried out for two different samples of static oriented liquid crystalline material at two different temperatures and a contact time of 2ms has been found to be optimal for such samples. Insection-B of this chapter, the initial preparation period of the experiment is considered as a possible means of increasing the sensitivity of the experiment. Thus the use of cross-polarization via the dipolar bath by the use of a diabatic demagnetization in the rotating frame(ADRF-CP) has been proposed to be incorporated into PISEMA. To understand the CP dynamics, magnetization in double-and zero-quantum reservoirs of an ensemble of spin-1/2 nuclei and their role in determining the sensitivity the experiments have been theoretically examined. Experimentally, a modification incorporating ADRF-CP is shown to result in enhancement of signal-to-noise by as much as 90% in the case of rigid single crystals of a model peptide and up to 50% in non-rigid, partially ordered liquid crystalline systems. In section-C another useful SLF technique known as PDLF spectroscopy has also been examined. In this case a sweep of one of the r.f. amplitudes(RAMP-CP),rather than ADRF is found to work well. The reason for the different behaviours has been discussed. Chapter-3 highlights two experimental approaches used to extract the chemical shift anisotropy(CSA) tensor information from rotating solids. Section-A is devoted to the measurement of the CSA values of thiophene by using MAS side band analysis, by extracting the principal values from the intensities of just a few spinning side bands. Experiments have been performed on thiophene-2 carboxylic acid and thiophene-3 carboxylic acid samples and the carbon CSA values have been obtained. In section-B, CSA values of carbons of the core unit of the liquid crystal4- hexyloxybenzoic acid (HBA) have been obtained by using the recoupling pulse sequence SUPER(Separation of Undistorted Powder patterns by Effortless Recoupling).HBA belongs to an important class of thermotropic liquid crystals which are structurally simple and often used as starting materials for many novel mesogens. As this molecule could serve as an ideal model compound, high resolution13C NMR studies of HBA in solution, solid and liquid crystalline phases have been also undertaken. The CSA values obtained from the 2D SUPER experiment showed good agreement to those computed by DFT calculations. The CSA values were used for obtaining the order parameter of the system at different temperatures. These matched well the order parameter obtained from the 13C-1 H dipolar couplings in the nematic phase determined by SLF spectroscopy at various temperatures. A knowledge of the CSA of the carbons is thus very useful, as they can be used for gaining knowledge about the system from the chemical shifts obtained from a simple 1D spectrum. In chapter-4, 1-and 2-dimensional13CNMR techniques have been utilized to obtain extensive information about some novel mesogenic molecules. Four molecules of different structure and topology have been taken up for study. These molecules have the following features. Mesogen-1 has a terminal hydroxyl group. Such systems with further modification can result in mesogenic monomers for side chain liquid crystalline polymers. Mesogen-2 has a dimethyl amino group at one end and has three phenyl groups connected by appropriate linking units that form the core. In the third case, mesogen-3, the terminal hydroxyl group of mesogen-1 is replaced with a hydrogen such that13C-1 H dipolar couplings provide directly information on molecular ordering and orientation. In the fourth case, mesogen-4, the core is built with four phenyl rings. Here the fourth ring is linked to other three rings via a flexible chain unit. In each of these cases the 2DSLFNMR experiments have been carried out where13C-1 H dipolar couplings as well as13C chemical shifts were used for obtaining the order parameters of various segments of the molecule. The data provide useful insight into the phase behaviour, ordering and orientation of the molecules. Chapter-5 discusses the applications of the natural abundance 13CNMR techniques to thiophene based mesogens, that have the potential for use in molecular electronics material. Typically, these molecules consist of phenyl rings appropriately connected by linking units with thiophene. Different core units as well as different linking units to thiophene have been considered. The six mesogens thus obtained have been investigated in detail using 1D and 2D NMR methods.13C-1 H dipolar couplings have been used to obtain ordering information, that show interesting correlation to the molecular orientation and dynamics.

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Book chapters on the topic "Mesogenic systems"

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Shibaev, V. P., Ya S. Freidzon, and S. G. Kostromin. "Molecular Architecture and Structure of Thermotropic Liquid Crystal Polymers with Mesogenic Side Groups." In Partially Ordered Systems, 77–120. New York, NY: Springer New York, 1994. http://dx.doi.org/10.1007/978-1-4613-8333-8_3.

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Dong, Ronald Y. "Internal Dynamics of Flexible Mesogens." In Partially Ordered Systems, 233–62. New York, NY: Springer New York, 1997. http://dx.doi.org/10.1007/978-1-4612-1954-5_8.

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Dong, Ronald Y. "Internal Dynamics of Flexible Mesogens." In Partially Ordered Systems, 213–35. New York, NY: Springer US, 1994. http://dx.doi.org/10.1007/978-1-4684-0208-7_8.

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I. Shabatina, Tatyana. "Self-Assembled Nanostructures Formation in Hybrid Metal-Mesogenic Systems." In Nanostructures in Energy Generation, Transmission and Storage. IntechOpen, 2019. http://dx.doi.org/10.5772/intechopen.83003.

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Cairns, Darran, Matthew Sousa, and Gregory Crawford. "Responsive Reactive Mesogen Microstructures." In Cross-Linked Liquid Crystalline Systems, 69–90. CRC Press, 2011. http://dx.doi.org/10.1201/b10525-5.

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Strohriegl, Peter. "Reactive Mesogens in Organic Light-Emitting Devices." In Cross-Linked Liquid Crystalline Systems, 319–46. CRC Press, 2011. http://dx.doi.org/10.1201/b10525-13.

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Amimori, Ichiro, and Tokuju Oikawa. "Viewing Angle Compensation Films for LCD Using Reactive Mesogens." In Cross-Linked Liquid Crystalline Systems, 91–118. CRC Press, 2011. http://dx.doi.org/10.1201/b10525-6.

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"Self-Assembly and Biomimetics." In Nanoscopic Materials: Size-Dependent Phenomena and Growth Principles, 296–326. 2nd ed. The Royal Society of Chemistry, 2014. http://dx.doi.org/10.1039/bk9781849739078-00296.

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Self-assembly is a process in which structural motives provide specific interaction for directed aggregation of the modular building blocks under equilibrium conditions. Interactions among the building blocks but also between building blocks and solvent play a role. This allows the formation of oriented unimolecular layers and bilayers, such as soap films or biological cell membranes. Depending on the shape of the units, oriented packing may lead to curvature. The interface of the layer to the solvent is associated with a small interfacial energy, and curved surfaces separate regimes of different pressure. In isotropic systems this leads to structures of constant curvature. Nature makes extensive use of these construction principles, and chemists can take advantage of them in biomimetic synthesis in the laboratory. The building motives are often elongated or polar organic molecules such as surfactants, but in liquid crystals the mesogenes can also be disc-shaped. The resulting soft matter structures can be used as moulds for the synthesis of quite artistic architectures from hard ceramics at or near room temperature via the sol–gel process. Alternatively, three-dimensional structures can be designed and synthesised from modules with specific coupling elements. Metal–organic frameworks are examples of such structures which after removal of the solvent are porous and may be stable, suitable for gas adsorption or separation, or catalysis.

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Conference papers on the topic "Mesogenic systems"

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Larichev, A. V., A. N. Simonov, and V. P. Shibaev. "Real time holography and phase conjugation in films of azo dye containing side-chain LC polymers." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.cfk7.

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Progress in the field of optical data processing and storage depends in great extent on development of the new effective nonlinear media [1]. Azo dye containing side-chain LC polymers are thought to be one of the perspective candidates for different optical applications because of their chemical stability and high nonlinear susceptibilities [2]. An attractive feature is the combination of liquid crystalline (LC) properties and optical nonlinear properties originating from light induced trans-cis isomerization of chromophores. The substance may be attributed to a class of two component nonlinear systems with vigorous intermolecular interaction. Behaviour of mesogenic (matrix) and dye subsystems are strongly correlated via the internal field. Thus, acting on the mesogenic subsystem by applying electric field and heating, it is possible to control the process of photo induced anisotropy formation in the polymeric bulk. However, the influence of the mentioned factors on the performance of the media in optical information systems is not clear yet.

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Ilavský, Michal, Jan Nedbal, Lenka Poláková, Zdeňka Sedlákova, Michio Tokuyama, Irwin Oppenheim, and Hideya Nishiyama. "Thermal and Dielectric Behavior of Liquid-Crystalline Polybutadiene-Diols with Mesogenic Groups in Side Chains." In COMPLEX SYSTEMS: 5th International Workshop on Complex Systems. AIP, 2008. http://dx.doi.org/10.1063/1.2897834.

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Mihara, Takashi, Hiroyuki Kohno, and Naoyuki Koide. "Physical properties of regioregular polythiophene derivatives containing mesogenic or ionic group in the side chain." In Smart Materials, Nano-, and Micro-Smart Systems, edited by Alan R. Wilson. SPIE, 2004. http://dx.doi.org/10.1117/12.585047.

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Torres, Yanira, Timothy White, Amber McClung, and William Oates. "Photoresponsive Azobenzene Liquid Crystal Polymer Networks: In Situ Photogenerated Stress Measurement." In ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3656.

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Azobenzene liquid crystal polymers and polymer networks are adaptive materials capable of converting light into mechanical work. Often, the photomechanical output of the azobenzene liquid crystal network (azo-LCN) is observed as a bending cantilever. The response of these materials can be either static (e.g. a simple bending cantilever) or dynamic (e.g. oscillating cantilever of 20–270 Hz). The resulting photomechanical output is dependent upon the domain orientation of the polymer network and the wavelength and polarization of the actinic light. Polydomain azobenzene liquid crystal polymer networks, which have the capability of bending both backwards and forwards with the change of polarization angle, are of particular interest. In the current study, three azo-LCNs are compared — two of them are equivalent in all respects except for one contains pendant azobenzene mesogens (1azo, azo-monoacrylate) and the other contains crosslinked azobenzene mesogens (2azo, azo-diacrylate). The third specimen has a combination of both mesogens. The mechanical behavior at different temperatures and examination of structure-property relationships in the polymerization process, including curing temperatures and liquid crystal cell alignment rubbing methods, were explored. Using dynamic mechanical analysis (DMA) the mechanical properties and the photogenerated stress and strain in the polymer are examined. It is found the differences in chemistry do correlate to small variation in the speed of photodirected bending, elastic modulus, and glass transition temperature. Despite these differences, all three azo-LCNs display nearly equivalent photogenerated stresses.

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