Doubly thermo-responsive nanoparticles constructed with two diblock copolymers prepared through the two macro-RAFT agents co-mediated dispersion RAFT polymerization

2015 ◽  
Vol 6 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Quanlong Li ◽  
Xin He ◽  
Yongliang Cui ◽  
Pengfei Shi ◽  
Shentong Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Increasing Temperature

Doubly thermo-responsive nanoparticles constructed with two diblock copolymers were prepared, and the nanoparticles exhibit a two-step phase-transition with increasing temperature.

Doubly thermo-responsive ABC triblock copolymer nanoparticles prepared through dispersion RAFT polymerization

2014 ◽  
Vol 5 (8) ◽  
pp. 2961-2972 ◽  
Author(s):  
Quanlong Li ◽  
Chengqiang Gao ◽  
Shentong Li ◽  
Fei Huo ◽  
Wangqing Zhang
Keyword(s):  
Phase Transition ◽  
Triblock Copolymer ◽  
Raft Polymerization ◽  
Abc Triblock Copolymer ◽  
Increasing Temperature

Doubly thermo-responsive triblock copolymer nanoparticles are prepared by a dispersion RAFT polymerization and the nanoparticles exhibit a two-step phase-transition with increasing temperature.

scholarly journals Aqueous one-pot synthesis of well-defined zwitterionic diblock copolymers by RAFT polymerization: an efficient and environmentally-friendly route to a useful dispersant for aqueous pigments

2021 ◽  
Vol 23 (3) ◽  
pp. 1248-1258
Author(s):  
Shannon M. North ◽  
Steven P. Armes
Keyword(s):  
Iron Oxide ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Environmentally Friendly ◽  
Iron Oxide Particles ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Effective ◽  
Oxide Particles

An atom-efficient, wholly aqueous one-pot synthesis of zwitterionic diblock copolymers has been devised. Such copolymers can serve as highly effective aqueous dispersants for nano-sized transparent yellow iron oxide particles.

scholarly journals Monoclinic–orthorhombic first-order phase transition in K2ZnSi5O12 leucite analogue; transition mechanism and spontaneous strain analysis.

2021 ◽  
pp. 1-20
Author(s):  
Anthony M.T. Bell ◽  
Francis Clegg ◽  
Christopher M.B. Henderson
Keyword(s):  
Phase Transition ◽  
Strain Analysis ◽  
Phase Region ◽  
Martensitic Transition ◽  
Two Phase ◽  
Spontaneous Strain ◽  
First Order ◽  
Transition Mechanism ◽  
First Order Phase Transition ◽  
Increasing Temperature

Abstract Hydrothermally synthesised K2ZnSi5O12 has a polymerised framework structure with the same topology as leucite (KAlSi2O6, tetragonal I41/a), which has two tetrahedrally coordinated Al3+ cations replaced by Zn2+ and Si4+. At 293 K it has a cation-ordered framework P21/c monoclinic structure with lattice parameters a = 13.1773(2) Å, b = 13.6106(2) Å, c = 13.0248(2) Å and β = 91.6981(9)°. This structure is isostructural with K2MgSi5O12, the first cation-ordered leucite analogue characterised. With increasing temperature, the P21/c structure transforms reversibly to cation-ordered framework orthorhombic Pbca. This transition takes place over the temperature range 848−863 K where both phases coexist; there is an ~1.2% increase in unit cell volume between 843 K (P21/c) and 868 K (Pbca), characteristic of a first-order, displacive, ferroelastic phase transition. Spontaneous strain analysis defines the symmetry- and non-symmetry related changes and shows that the mechanism is weakly first order; the two-phase region is consistent with the mechanism being a strain-related martensitic transition.

Construction of Rod-Forming Single Network Mesophases in Rod–Coil Diblock Copolymers via Inversely Designed Phase Transition Pathways

2018 ◽  
Vol 51 (15) ◽  
pp. 5773-5787 ◽  
Author(s):  
Tongjie Sun ◽  
Faqiang Liu ◽  
Ping Tang ◽  
Feng Qiu ◽  
Yuliang Yang
Keyword(s):  
Phase Transition ◽  
Diblock Copolymers ◽  
Transition Pathways

Synthesis of azobenzene-containing side chain liquid crystalline diblock copolymers using RAFT polymerization and photo-responsive behavior

2013 ◽  
Vol 130 (3) ◽  
pp. 2165-2175 ◽  
Author(s):  
Wuqiong Sun ◽  
Xiaohua He ◽  
Xiaojuan Liao ◽  
Shaoliang Lin ◽  
Wei Huang ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Side Chain ◽  
Responsive Behavior

Change of Phase Transition Temperature in Band Engineered Ferroelectric Lanthanum-Modified Bismuth Titanates

2020 ◽  
Vol 20 (11) ◽  
pp. 7135-7139
Author(s):  
Rui Tang ◽  
Sangmo Kim ◽  
Chung Wung Bark
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Ferroelectric Properties ◽  
Solar Spectrum ◽  
Ferroelectric Material ◽  
Transition Temperatures ◽  
Phase Transition Temperatures ◽  
Increasing Temperature

The ferroelectric material chosen for a solar cell has to absorb as much of the solar spectrum as possible, therefore a low band gap is desirable, but it is rarely known for phase transition temperature on the bandgap engineered ferroelectric materials. The phase transition temperature of a ferroelectric material can be determined by monitoring its dielectric constant with increasing temperature, as the dielectric constant changes abruptly at the phase transition temperature. Here, we inform the measurement of the phase transition temperature of the ferroelectric complex oxide Bi3.25La0.75Ti3O12 as well as cobalt and iron doped Bi3.25La0.75Ti3O12 bulk ceramics for photovoltaic cells based on dielectric monitoring with changing temperature. We synthesized lanthanum-modified bismuth-titanate-based ceramics with various doping concentrations transition metal to Ti. X-ray diffraction analysis revealed that all the compounds crystallized in an orthorhombic structure. Their morphologies and size distributions were observed using scanning electron microscopy. From the ultraviolet-visible spectroscopy absorption spectra of the synthesized powder, bandgaps were checked. An inductance-capacitance-resistance meter was used to obtain the relationship between dielectric responses and the temperature of the targets in a tube furnace. We observed that the dielectric constant increases gradually with increasing temperature, until the transition temperature and subsequently decreases, and we were able to determine the phase transition temperatures of the tested materials. Furthermore, the results revealed that all the doped bismuth titanates keep their phase transition temperatures, which were sufficiently high, to maintain their ferroelectric properties above room temperature.

scholarly journals Doubly Dynamic Hydrogel Formed by Combining Boronate Ester and Acylhydrazone Bonds

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 487
Author(s):  
Yusheng Liu ◽  
Yigang Liu ◽  
Qiuxia Wang ◽  
Yugui Han ◽  
Hao Chen ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Solid Content ◽  
Self Healing ◽  
Covalent Bonds ◽  
Boronate Ester ◽  
Isopropyl Acrylamide ◽  
Reversible Addition ◽  
The Difference

The incorporation of double dynamic bonds into hydrogels provides an effective strategy to engineer their performance on demand. Herein, novel hydrogels were PREPARED by combining two kinetically distinct dynamic covalent bonds, boronate ester and acylhydrazone bonds, and the synergistic properties of the hydrogels were studied comprehensively. The functional diblock copolymers P(N-isopropyl acrylamide-co-N-acryloyl-3-aminophenylboronic acid)-b-(N-isopropyl acrylamide-co-diacetone acrylamide) (PAD) were prepared via reversible addition−fragmentation chain transfer (RAFT) polymerization. The hydrogel was constructed by exploiting dynamic reaction of phenyboronic acid moieties with polyvinyl alcohol (PVA) and ketone moieties with adipic dihydrazide (ADH) without any catalyst. The active boronate ester linkage endows the hydrogel with fast gelation kinetics and self-healing ability, and the stable acylhydrazone linkage can enhance the mechanical property of the hydrogel. The difference in kinetics endows that the contribution of each linkage to mechanical strength of the hydrogel can be accurately estimated. Moreover, the mechanical property of the hydrogel can be readily engineered by changing the composition and solid content, as well as by controlling the formation or dissociation of the dynamic linkages. Thus, we provide a promising strategy to design and prepare multi-responsive hydrogels with tunable properties.

Synthesis of POSS-functionalized liquid crystalline block copolymers via RAFT polymerization for stabilizing blue phase helical soft superstructures

2018 ◽  
Vol 9 (16) ◽  
pp. 2101-2108 ◽  
Author(s):  
Jianqiu Jin ◽  
Mingjie Tang ◽  
Zhenghe Zhang ◽  
Kang Zhou ◽  
Yun Gao ◽  
...  
Keyword(s):  
Phase Transition ◽  
Liquid Crystals ◽  
Block Copolymers ◽  
Liquid Crystalline ◽  
Raft Polymerization ◽  
Phase Liquid ◽  
Blue Phase

A study of the phase transition behaviors of blue phase liquid crystals containing different amounts of POSS-functionalized LC BCPs.

Sound velocity of neon at high pressures and temperatures by Brillouin scattering

2019 ◽  
Vol 104 (11) ◽  
pp. 1650-1655
Author(s):  
Wei Wei ◽  
Xinyang Li ◽  
Ningyu Sun ◽  
Sergey N. Tkachev ◽  
Zhu Mao
Keyword(s):  
Phase Transition ◽  
High Pressures ◽  
Velocity Structure ◽  
Solid Phase ◽  
Brillouin Scattering ◽  
Compressional Wave ◽  
Rare Gases ◽  
Apparent Reduction ◽  
Diamond Anvil ◽  
Increasing Temperature

Abstract In this study, we have determined the combined effect of pressure and temperature on the compressional-wave velocity (VP) of Ne up to 53 GPa and 1100 K using Brillouin scattering in externally heated diamond-anvil cells. The phase transition from the supercritical fluid to solid phase was observed to cause a 10.5–11% jump in VP, and the magnitude in the VP contrast across the phase transition increases with temperature. In addition, we have observed an abnormal reduced increase rate of VP with pressure in the supercritical Ne fluid at both 800 and 1100 K before the transition to the solid phase. VP of the solid Ne exhibits a nonlinear increase with pressure at all the investigated temperatures. The elevating temperature was noted to cause an apparent reduction in VP, yet the reduction in VP caused by increasing temperature dramatically decreases at higher pressures. At 20 GPa, increasing temperature by 100 K can lower the VP of Ne by 2.4%. Yet elevating temperature by 100 K can only reduce the VP by 0.4% at 50 GPa. We further compare VP of Ne to that of other rare gases, including Ar, Kr, and Xe. At 300 K, VP of Ne shows a stronger dependence on pressure than both Kr and Xe. Moreover, increasing temperature can produce a greater reduction in VP of Ne than that of Ar below 50 GPa. Our measured VP of Ne is also useful for understanding the velocity structure of giant planets, such as Jupiter.

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