Reversible switching of the shear modulus of photoresponsive liquid-crystalline polymers.
نویسندگان
چکیده
Manipulation makes light work: The morphology and rheological properties of a liquid-crystalline system can be dynamically manipulated with UV light by attaching photoresponsive liquid-crystalline moieties to a siloxane-based polymer. Stimulation with UV light induces a conformational change in the molecule, which disrupts the liquid-crystalline mesophase (see picture), and results in a dramatic change in its rheological properties.
منابع مشابه
Synthesis of a photoresponsive liquid-crystalline polymer containing azobenzene.
The synthesis of an oriented liquid-crystalline photoresponsive polymer, prepared by polymerization of mono- and di-acrylates, both of which contain azobenzene chromophores, is reported. The prepared free-standing polymer film shows strong reversible photoinduced deformation upon exposure to unpolarized UV light at 366 nm, as a result of an optically induced isomeric change of the azobenzene mo...
متن کاملUltrasonic measurements of the elastic moduli of liquid crystalline polymers
The five independent elastic moduli of extruded rods of two thermotropic liquid crystalline polymers, Vectra B900 and Vectra A950, and the nine independent moduli of an injection-moulded bar of Vectra A950 have been measured by ultrasonic methods at 10 MHz. For Vectra B900, the sharp rise in the axial extensional modulus C33 and the moderate drop in the transverse modulus C 11 with increasing d...
متن کاملStilbene-containing Thermotropic Liquid Crystalline Polyesters for Aerospace Applications
Materials used in space travel must maintain thermal and dimensional stability in extreme conditions, while remaining melt processable for ease of industrial production. The rigid chemical structure of stilbene often correlates to polymers exhibiting a liquid crystalline morphology and the olefinic bond undergoes a [2 + 2] cycloaddition in the presence of UV light. Based on the combined benefit...
متن کاملPolymer communication Rapid viscoelastic switching of an ambient temperature range photo-responsive azobenzene side chain liquid crystal polymer
A B S T R A C T We report the rheological properties of a new azobenzene side chain liquid crystal polymer (SCLCP) with photo-responsive behavior in the range of 0ºC to 50ºC as probed by small amplitude oscillatory shear (SAOS) rheometry with in situ UV irradiation. In the linear viscoelastic (LVE) strain regime, temperature sweeps measured G' and G " from 80°C to-5°C and identified glass trans...
متن کاملA Rewritable, Reprogrammable, Dual Light‐Responsive Polymer Actuator
We report on the fabrication of a rewritable and reprogrammable dual-photoresponsive liquid crystalline-based actuator containing an azomerocyanine dye that can be locally converted into the hydroxyazopyridinium form by acid treatment. Each dye absorbs at a different wavelength giving access to programmable actuators, the folding of which can be controlled by using different colors of light. Th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Angewandte Chemie
دوره 48 19 شماره
صفحات -
تاریخ انتشار 2009