scholarly journals Stimuli-Responsive Nanodiamond–Polyelectrolyte Composite Films

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 507 ◽  
Author(s):  
Tony Tiainen ◽  
Marina Lobanova ◽  
Erno Karjalainen ◽  
Heikki Tenhu ◽  
Sami Hietala
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Composite Films ◽  
Complexing Agent ◽  
Mechanical And Thermal Properties ◽  
Stimuli Responsive ◽  
Phase Transition Behavior ◽  
Thermally Induced ◽  
Reversible Phase Transition ◽  
Reversible Phase

Nanodiamonds (NDs) can considerably improve the mechanical and thermal properties of polymeric composites. However, the tendency of NDs to aggregate limits the potential of these non-toxic, mechanically- and chemically-robust nanofillers. In this work, tough, flexible, and stimuli-responsive polyelectrolyte films composed of cross-linked poly(butyl acrylate-co-dimethylaminoethyl methacrylate) (P(BA-co-DMAEMA)) were prepared by photopolymerization. The effects of the added carboxylate-functionalized NDs on their mechanical and stimuli-responsive properties were studied. When the negatively charged NDs were added to the polymerization media directly, the mechanical properties of the films changed only slightly, because of the uneven distribution of the aggregated NDs in the films. In order to disperse and distribute the NDs more evenly, a prepolymerized polycation block copolymer complexing agent was used during the photopolymerization process. This approach improved the mechanical properties of the films and enhanced their thermally-induced, reversible phase-transition behavior.

scholarly journals Above Room Temperature Reversible Phase Transition Induces Distinct Dielectric and Nonlinear Optical Switching Response Behavior in Crown-Ether-Based Supramolecular Clathrate

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 184 ◽  
Author(s):  
Jing Jing ◽  
Fan Jiang ◽  
Yan-Li Wei ◽  
Chao Shi ◽  
Heng-Yun Ye ◽  
...  
Keyword(s):  
Phase Transition ◽  
Crown Ether ◽  
Optical Switching ◽  
Nonlinear Optical ◽  
Thermal Hysteresis ◽  
Switching Behavior ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Reversible Phase Transition ◽  
Reversible Phase

Stimuli-responsive materials with coexisting nonlinear optical (NLO) and dielectric properties are technologically important, which enable simultaneous conversion of optoelectronic properties between different states under external stimuli. By rationally screening guest cations (C6H5NF2)+ in the crown-ether inclusion system, we synthesized a crown-ether supramolecular compound [(C6H5NF2)(18-crown-6)][PF6] (1). Differential scanning calorimetry (DSC) showed that 1 undergoes a reversible phase transition above room temperatures (305 K/292 K), with a thermal hysteresis of 13 K. Temperature-dependent dielectric and NLO measurements show that the compound exhibits two distinct switching response behaviors. Structural analysis indicates that the order–disorder change of the host molecule 18-crown-6 and the guest organic cation during the phase transition induces the dielectric and NLO switching behavior of the compound.

scholarly journals Thermoresponsive Polypeptoids

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2973
Author(s):  
Dandan Liu ◽  
Jing Sun
Keyword(s):  
Phase Transition ◽  
Functional Groups ◽  
Synthetic Methods ◽  
Stimuli Responsive ◽  
Thermoresponsive Polymers ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Reversible Phase Transition ◽  
Polymer Architectures ◽  
Reversible Phase

Stimuli-responsive polymers have been widely studied in many applications such as biomedicine, nanotechnology, and catalysis. Temperature is one of the most commonly used external triggers, which can be highly controlled with excellent reversibility. Thermoresponsive polymers exhibiting a reversible phase transition in a controlled manner to temperature are a promising class of smart polymers that have been widely studied. The phase transition behavior can be tuned by polymer architectures, chain-end, and various functional groups. Particularly, thermoresponsive polypeptoid is a type of promising material that has drawn growing interest because of its excellent biocompatibility, biodegradability, and bioactivity. This paper summarizes the recent advances of thermoresponsive polypeptoids, including the synthetic methods and functional groups as well as their applications.

Research in Toughening Wear-Resistant of Alumina Ceramic

2013 ◽  
Vol 750-752 ◽  
pp. 537-540
Author(s):  
Zhan Shen Zheng ◽  
Sen Geng ◽  
Rong Yang
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Tetragonal Zirconia ◽  
Density Measurement ◽  
Alumina Ceramic ◽  
Monoclinic Zirconia ◽  
Hardness Testing ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
Sem Test

This article describes the alumina ceramic mixed with two kinds of additives in order to improve the performance of ceramic, such as mixed with submicron ZrO2 and MnO2 Monoclinic zirconia (m-ZrO2) and tetragonal zirconia (t-ZrO2) of reversible phase transition of volume change is used to improve the toughness and wear resistance of composite alumina ceramic. Through doing various tests about fired products, including hardness testing, SEM test and bulk density measurement, we can understand the microstructure and mechanical properties of samples.

scholarly journals Macroscopic crystalline deformation in an organic dye during reversible phase transition caused by alkyl disorder

CrystEngComm ◽  
2018 ◽  
Vol 20 (19) ◽  
pp. 2644-2647 ◽  
Author(s):  
Takaya Minami ◽  
Hiroyasu Sato ◽  
Shinya Matsumoto
Keyword(s):  
Phase Transition ◽  
Single Crystals ◽  
Organic Dye ◽  
Thermally Induced ◽  
Reversible Phase Transition ◽  
Reversible Phase

Single crystals of a bisazomethine dye exhibit thermally induced reversible crystalline deformation due to alkyl disorder.

Temperature-Dependent Solid-state Luminescence and Reversible Phase Transition of (n-Bu4N)[Au(SC6H3-3,5-Me2)2]

2003 ◽  
Vol 32 (11) ◽  
pp. 1002-1003 ◽  
Author(s):  
Seiji Watase ◽  
Takayuki Kitamura ◽  
Nobuko Kanehisa ◽  
Masami Nakamoto ◽  
Yasushi Kai ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Temperature Dependent ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
State Luminescence
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