scholarly journals Photorheological fluids of azobenzene polymers for lubrication regulation

Friction ◽  
2021 ◽  
Author(s):  
Shuangxi Tang ◽  
Shayu Li ◽  
Liran Ma ◽  
Yu Tian
Keyword(s):  
Ultraviolet Light ◽  
Near Infrared ◽  
Practical Importance ◽  
Structural Difference ◽  
Molecular Structures ◽  
Infrared Light ◽  
Fluid Viscosity ◽  
Light Radiation ◽  
Near Infrared Light ◽  
Photorheological Fluids

AbstractFluid viscosity is ubiquitous property and is of practical importance in intelligent fluids, industrial lubrication, and pipeline fluid transportation. Recently, there has been a surging interest in viscosity regulation. Here, we have developed a group of photorheological fluids by utilizing azobenzene polymers with a light-induced microstructure transformation. In this work, a photosensitive polymer with 4,4′-bis-hydroxyazobenzene as the main chain was designed and synthesized as a pivotal functional material. The sufficiently large structural difference under ultraviolet and near-infrared light makes it possible to regulate the viscosity of a polyethylene glycol solution. The viscosity of the photosensitive rheological fluids under ultraviolet light radiation is found to be up to 45.1% higher than that under near-infrared light radiation. To explore this intelligent lubricating technology, the friction regulation of ceramic sliding bearings was investigated utilizing photosensitive rheological fluids. Reversible friction regulation with a ratio of up to 3.77 has been achieved by the alternative irradiation of near-infrared and ultraviolet light, which can be attributed to the differences in mechanical properties and molecular structures under ultraviolet and near-infrared light according to both simulations and experiments. Such photorheological fluids will have promising applications in controllable lubrication, intelligent rheological fluids, and photosensitive dampers.

Changes in Sensory and Pain Perception Thresholds After Linear Polarized Near-Infrared Light Radiation in the Trigeminal Region

CRANIO® ◽  
2005 ◽  
Vol 23 (3) ◽  
pp. 174-178 ◽  
Author(s):  
Koji Kashima ◽  
Naoshi Watanabe ◽  
Shuichi Higashinaka ◽  
Sho Maeda ◽  
Ryosuke Shiba
Keyword(s):  
Pain Perception ◽  
Near Infrared ◽  
Infrared Light ◽  
Light Radiation ◽  
Near Infrared Light ◽  
Trigeminal Region

Synthesis, characterization, photophysical properties, and computational studies on N-hexylphenothiazine/cyanopyridine based π-conjugated copolymers

2021 ◽  
pp. 095400832098875
Author(s):  
Ashraf A El-Shehawy ◽  
Adel M Attia ◽  
Abdul-Rahman IA Abdallah ◽  
Morad M El-Hendawy
Keyword(s):  
Density Functional ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Coupling Reaction ◽  
Molecular Structures ◽  
Degree Of Crystallinity ◽  
Infrared Light ◽  
Photovoltaic Properties ◽  
Near Infrared Light ◽  
Conjugated Copolymers

In this paper, π-conjugated copolymers, namely N-hexylphenothiazine/cyanopyridine/phenyl/benzothiadiazole, N-hexylphenothiazine/cyanopyridine/phenyl/9,9-dihexylfluorene, and N-hexylphenothiazine/cyanopyridine/phenyl/9,9-diethylhexylfluorene were readily synthesized via Pd-catalyzed Suzuki cross-coupling reaction. The polymer structures and their photophysical properties were characterized by elemental analysis, 1H NMR, GPC, TGA, XRD, UV-vis absorption and PL spectroscopy measurements. The coupling agent effect on photophysical properties of copolymers was investigated to rationally design polymers with particular physical properties to be employed in optoelectronic devices. The UV-vis absorption spectroscopy of copolymers showed λmax at a range of ∼334–474 nm and red-shifted in their films to a range of ∼342–381 nm. These copolymers displayed highly intense fluorescence in their solutions and films. The PL spectra of copolymers indicated red and near-infrared light, rendering them a prospect for being red and near-infrared light-emitting materials for PLEDs. XRD analysis demonstrated a d-spacing range of ∼3.79–4.32 Å, reflecting π-π stacking and some degree of crystallinity in some polymers, and only P1 and P2 showed peaks in the small-angle region, indicating lamellar structures. To understand the relationship between molecular structures of target materials and their photophysical and photovoltaic properties, density functional theory (DFT) and its time-dependent form (TD-DFT) were employed.

Frequency effects of near-infrared light radiation on the forehead as quantified by EEG measurements

2021 ◽  
Author(s):  
Liuye Yao ◽  
Zhiyu Qian ◽  
Lu Zhou ◽  
Yu Zhang ◽  
Yangyang Liu ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Light Radiation ◽  
Near Infrared Light ◽  
Frequency Effects

Cu2−xSe@mSiO2–PEG core–shell nanoparticles: a low-toxic and efficient difunctional nanoplatform for chemo-photothermal therapy under near infrared light radiation with a safe power density

Nanoscale ◽  
2014 ◽  
Vol 6 (8) ◽  
pp. 4361-4370 ◽  
Author(s):  
Xijian Liu ◽  
Qian Wang ◽  
Chun Li ◽  
Rujia Zou ◽  
Bo Li ◽  
...  
Keyword(s):  
Power Density ◽  
Photothermal Therapy ◽  
Near Infrared ◽  
Infrared Light ◽  
Core Shell ◽  
Light Radiation ◽  
Shell Nanoparticles ◽  
Near Infrared Light ◽  
Nir Light ◽  
Core Shell Nanoparticles

A difunctional nanoplatform based on the Cu2−xSe@mSiO2–PEG core–shell nanoparticles demonstrates an excellent biocompatibility and can be used for combining photothermal- and chemotherapies driven by NIR light.

An ordered copper nanowell-array film with near-perfect broadband absorption from ultraviolet to near-infrared light

2020 ◽  
Vol 59 (11) ◽  
pp. 110906
Author(s):  
Juan Shen ◽  
Yong Ren ◽  
Xinxin Zhu ◽  
Min Mao ◽  
Quan Zhou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Broadband Absorption

scholarly journals Recent Near-Infrared Light-Activated Nanomedicine toward Precision Cancer Therapy

2021 ◽  
Author(s):  
Xiaowei Luan ◽  
Yongchun Pan ◽  
Yanfeng Gao ◽  
Yujun Song
Keyword(s):  
Cancer Therapy ◽  
Near Infrared ◽  
Infrared Light ◽  
Human Society ◽  
Near Infrared Light ◽  
History Of ◽  
The Universe

Light has witnessed the history of mankind and even the universe. It is of great significances to the life of human society, contributing to energy, agriculture, communication, and much more....

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