scholarly journals Photo Actuation Performance of Nanotube Sheet Incorporated Azobenzene Crosslinked Liquid Crystalline Polymer Nanocomposite

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 735 ◽  
Author(s):  
Meng Bi ◽  
Yifan He ◽  
Yuchang Wang ◽  
Wenlong Yang ◽  
Ban Qin ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Microelectromechanical Systems ◽  
In Situ Polymerization ◽  
Uv Light ◽  
Polymer Network ◽  
Polymer Nanocomposite ◽  
Crystalline Polymer ◽  
Light Irradiation ◽  
Nanocomposite Films ◽  
Biological Engineering

Crosslinked liquid crystalline polymers (CLCPs) containing azobenzene (AZO-CLCPs) are a type of promising material due to their significance in the design of light-driven smart actuators. Developing AZO-CLCP composites by incorporating AZO-CLCPs with other materials is an effective way of enhancing their practicability. Herein, we report an AZO-CLCP/CNT nanocomposite prepared by the in situ polymerization of diacrylates containing azobenzene chromophores on carbon nanotube (CNT) sheets. The liquid crystal phase structure of CLCP matrix was evidenced by the two-dimensional X-ray scattering. The prepared pure AZO-CLCP films and AZO-CLCP/CNT nanocomposite films demonstrated strong reversible photo-triggered deformation under the irradiation of UV light at 366 nm of wavelength, as a result of photo-induced isomerization of azobenzene moieties in the polymer network. But compared to pure AZO-CLCP films, the AZO-CLCP/CNT nanocomposite films could much more rapidly return to their initial shapes after the UV light irradiation was removed due to the elasticity effect of CNT sheets. The deformation behavior of AZO-CLCP/CNT nanocomposite films under the light irradiation was also different from that of the pure AZO-CLCP films due to the interfacial interaction between a polymer network and CNT sheet. Furthermore, incorporation of a CNT sheet remarkably increased the mechanical strength and robustness of the material. We also used this AZO-CLCP/CNT nanocomposite as a microvalve membrane actuator, which can be controlled by light, for a conceptual device of a microfluidic system. The results showed that this AZO-CLCP/CNT nanocomposite may have great potential in smart actuator applications for biological engineering, medical treatment, environment detection and microelectromechanical systems (MEMS), etc.

scholarly journals Photocatalytic Degradation of Methylene Blue under UV Light Irradiation on Prepared CarbonaceousTiO2

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zatil Amali Che Ramli ◽  
Nilofar Asim ◽  
Wan N. R. W. Isahak ◽  
Zeynab Emdadi ◽  
Norasikin Ahmad-Ludin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
In Situ Polymerization ◽  
Uv Light ◽  
Carbon Composite ◽  
Light Irradiation ◽  
Uv Light Irradiation ◽  
Transmission Electron ◽  
Vis Spectroscopy

This study involves the investigation of altering the photocatalytic activity of TiO2using composite materials. Three different forms of modified TiO2, namely, TiO2/activated carbon (AC), TiO2/carbon (C), and TiO2/PANi, were compared. The TiO2/carbon composite was obtained by pyrolysis of TiO2/PANi prepared by in situ polymerization method, while the TiO2/activated carbon (TiO2/AC) was obtained after treating TiO2/carbon with 1.0 M KOH solution, followed by calcination at a temperature of 450°C. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TG-DTA), Brunauer-Emmet-Teller (BET), and UV-Vis spectroscopy were used to characterize and evaluate the prepared samples. The specific surface area was determined to be in the following order: TiO2/AC > TiO2/C > TiO2/PANi > TiO2(179 > 134 > 54 > 9 m2 g−1). The evaluation of photocatalytic performance for the degradation of methylene blue under UV light irradiation was also of the same order, with 98 > 84.7 > 69% conversion rate, which is likely to be attributed to the porosity and synergistic effect in the prepared samples.

Humidity-Responsive Bilayer Actuators Based on a Liquid-Crystalline Polymer Network

2013 ◽  
Vol 5 (11) ◽  
pp. 4945-4950 ◽  
Author(s):  
Mian Dai ◽  
Olivier T. Picot ◽  
Julien M. N. Verjans ◽  
Laurens T. de Haan ◽  
Albertus P. H. J. Schenning ◽  
...  
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Polymer Network ◽  
Crystalline Polymer

SYNTHESIS AND CHARACTERIZATION OF THERMOTROPIC LIQUID CRYSTALLINE POLYESTER/MULTI-WALLED CARBON NANOTUBE NANOCOMPOSITES

NANO ◽  
2009 ◽  
Vol 04 (06) ◽  
pp. 339-344
Author(s):  
J. J. WANG ◽  
W. F. ZHAO ◽  
J. G. HE ◽  
Z. P. DONG ◽  
R. LI
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
In Situ Polymerization ◽  
Crystalline Polymer ◽  
Transition Temperatures ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermogravimetric Analyzer ◽  
Temperature Solution ◽  
Matrix Differential

A thermotropic liquid crystalline polymer (TLCP) was synthesized from 4, 4'-Oxobisbenzoic acid and methylhydroquinone by low-temperature solution polycondensation. Nanocomposites of TLCP with the content of MWNTs from 0 wt% to 10 wt% were prepared by in situ polymerization. Scanning electron microscopy images showed that the MWNTs were well-separated in the TLCP matrix. Differential scanning calorimetry, thermogravimetric analyzer, X-ray diffraction, and polarized optical microscopy were used to investigate the thermal behavior, crystalline structure and liquid crystalline properties of the pure TLCP and TLCP/MWNT nanocomposites. The thermogravimetric analyses indicated that a small amount of MWNTs could improve the thermal stability of TLCP matrix. Furthermore, the result of differential scanning calorimetry demonstrated that both melt transition temperatures and isotropic transition temperatures of the hybrids were enhanced. Our study provided a design guide for CNT-filled TLCP composites which could be favorable for industrial use.

Optically and thermally activated shape memory supramolecular liquid crystalline polymers

2016 ◽  
Vol 4 (22) ◽  
pp. 4946-4953 ◽  
Author(s):  
Shangyi Fu ◽  
Hu Zhang ◽  
Yue Zhao
Keyword(s):  
Shape Memory ◽  
Liquid Crystalline ◽  
Uv Light ◽  
Crystalline Polymer ◽  
Crystalline Polymers ◽  
Thermally Activated ◽  
Azobenzene Mesogens ◽  
Triple Shape Memory ◽  
Spatiotemporal Control ◽  
Polymer Bearing

A supramolecular side-chain liquid crystalline polymer bearing azobenzene mesogens exhibits not only the triple-shape memory effect but also UV light-enabled spatiotemporal control of shape recovery.

Preparation of Low-K Fluorinated Polyimide/Phlogopite Nanocomposites

2008 ◽  
Vol 47-50 ◽  
pp. 987-990
Author(s):  
Yi He Zhang ◽  
Qing Song Su ◽  
Li Yu ◽  
Li Bing Liao ◽  
Hong Zheng ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Layered Silicate ◽  
Polymer Nanocomposite ◽  
Nanocomposite Films ◽  
Polymerization Process ◽  
Ultrasonic Dispersion ◽  
Thermal Stabilities ◽  
Fluorinated Polyimide ◽  
Polyimide Matrix

Phlogopite with layered silicate structure had been firstly chemically modified via an in situ intercalation method, and phlogopite-polymer nanocomposite films were prepared from 2,2'-bis (3,4-dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and oxydimethyl aniline (ODA) in N,N-dimethylacetamide as a solvent by using in-situ polymerization process combined with ultrasonic dispersion and multi-step curing. The structure of phlogopite minerals and its polymer nanocomposites were characterized by X-ray diffraction (XRD) and infrared spectra (FTIR) respectively. The experimental results indicated that the phlogopites with layered nanostructure had lost their ordered structure and had been exfoliated or intercalated. Thereafter, they were dispersed randomly in the polyimide matrix. The dependence of dielectric properties and thermal stabilities of the nanocomposite films on the phlogopite content and frequency were studied.

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