Synthesis by ATRP and effects of molecular weight on photomechanical properties of liquid crystalline polymers containing side-chain azobenzene chromophores

Angiolini, Luigi; Benelli, Tiziana; Giorgini, Loris; Paris, Fabio; Salatelli, Elisabetta; Fontana, Marco; Camorani, Paolo

doi:10.1016/j.eurpolymj.2008.07.019

Cited by 14 publications

(10 citation statements)

References 32 publications

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“…On the other hand it does not offer the possibility of a permanent shape‐memory effect: if the material is heated above the T g of the hard‐block, the orientation information is lost. For the preparation of the defined block‐copolymer structure, modern methods of controlled polymerization such as atom transfer radical polymerization (ATRP) and ring‐opening metathesis polymerization (ROMP) could be successfully applied on liquid crystalline materials 31, 48–52…”

Section: General Considerationsmentioning

confidence: 99%

Liquid Crystalline Elastomers as Actuators and Sensors

2010

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This review collects recent developments in the field of liquid crystalline elastomers (LCEs) with an emphasis on their use for actuator and sensor applications. Several synthetic pathways leading to crosslinked liquid crystalline polymers are discussed and how these materials can be oriented into liquid crystalline monodomains are described. By comparing the actuating properties of different systems, general structure-property relationships for LCEs are obtained. In the final section, how these materials can be turned into usable devices using different interdisciplinary techniques are described.

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Section: General Considerationsmentioning

confidence: 99%

Liquid Crystalline Elastomers as Actuators and Sensors

2010

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“…There are many methods for depositing pNIPAM onto a substrate, including atom transfer radical polymerization (ATRP), electron beam ionization, and solution deposition [14,35,41,45–47]. Previously, we compared two methods of deposition (plasma and co-deposition with a sol-gel), demonstrating that both were technically appropriate for obtaining thermoresponsive pNIPAM films.…”

Section: Introductionmentioning

confidence: 99%

Effect of substrate storage conditions on the stability of “Smart” films used for mammalian cell applications

Bluestein

Reed

Canavan

2017

Applied Surface Science

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When poly(N-isopropyl acrylamide) (pNIPAM) is tethered to a surface, it can induce the spontaneous release of a sheet of mammalian cells. The release of cells is a result of the reversible phase transition the polymer undergoes at its lower critical solution temperature (LCST). Many techniques are used for the deposition of pNIPAM onto cell culture substrates. Previously, we compared two methods of deposition (plasma polymerization, and co-deposition with a sol-gel). We proved that although both were technically appropriate for obtaining thermoresponsive pNIPAM films, the surfaces that were co-deposited with a sol-gel caused some disruption in cell activity. The variation of cell behavior could be due to the delamination of pNIPAM films leaching toxic chemicals into solution. In this work, we assessed the stability of these pNIPAM films by manipulating the storage conditions and analyzing the surface chemistry using X-ray photoelectron spectroscopy (XPS) and contact angle measurements over the amount of time required to obtain confluent cell sheets. From XPS, we demonstrated that ppNIPAM (plasma polymerized NIPAM) films remains stable across all storage conditions while sol-gel deposition show large deviations after 48 h of storage. Cell response of the deposited films was assessed by investigating the cytotoxicity and biocompatibility. The 37°C and high humidity storage affects sol-gel deposited films, inhibiting normal cell growth and proper thermoresponse of the film. Surface chemistry, thermoresponse and cell growth remained similar for all ppNIPAM surfaces, indicating these substrates are more appropriate for mammalian cell culture applications.

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“…Photosensitive materials have attracted considerable attention in the past several decades, since the photochemical reactions in organic materials may induce many changes in the properties, such as solubility, optical behavior, photomechanical effect, refractive index, and dielectric constant [1][2][3][4][5][6]. Among the photosensitive materials, the UV-sensitive polymers have been highlighted because of their excellent properties and wide applications in many fields.…”

Section: Introductionmentioning

confidence: 99%

Novel UV-sensitive bis-chalcone derivatives: synthesis and photocrosslinking properties in solution and solid PMMA film

et al. 2011

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A series of chalcone derivatives in which two chalcone groups are attached by alkyldioxy chains were synthesized and characterized by 1 H NMR, UV-Vis, and Fourier transform infrared (FTIR) spectral analysis. Upon the irradiation of 365-nm UV light, the chalcone groups in the molecules underwent [2p ? 2p] photodimerization. The photocrosslinking properties were investigated both in solution and in polymethyl methacrylate (PMMA) solid films on quartz plate. It has been found that the photocrosslinking rates of the compounds depended on the different flexibility of the functional groups, which was determined by the length of the spacer chain between the two chalcone moieties. The longest soft chain containing derivatives has a faster photocrosslinking rate both in solution and in solid film. Irradiated by polarized ultraviolet light (PUV), all of the films doped with bis-chalcone derivatives showed an anisotropic absorption property, which may give a promising application as LC-alignment materials.

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Synthesis by ATRP and effects of molecular weight on photomechanical properties of liquid crystalline polymers containing side-chain azobenzene chromophores

Cited by 14 publications

References 32 publications

Liquid Crystalline Elastomers as Actuators and Sensors

Liquid Crystalline Elastomers as Actuators and Sensors

Effect of substrate storage conditions on the stability of “Smart” films used for mammalian cell applications

Novel UV-sensitive bis-chalcone derivatives: synthesis and photocrosslinking properties in solution and solid PMMA film

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