Ultrasonic Absorption in Triethylamine‐Water Solution near its Critical Solution Temperature

1970 ◽  
Vol 47 (1A) ◽  
pp. 98-98
Author(s):  
S. S. Yun
Keyword(s):  
Water Solution ◽  
Solution Temperature ◽  
Ultrasonic Absorption ◽  
Critical Solution Temperature

Removal of metal ions from aqueous effluents involving new thermosensitive polymeric sorbent

2013 ◽  
Vol 67 (6) ◽  
pp. 1181-1187 ◽  
Author(s):  
A. Graillot ◽  
S. Djenadi ◽  
C. Faur ◽  
D. Bouyer ◽  
S. Monge ◽  
...  
Keyword(s):  
Water Solution ◽  
Sorption Properties ◽  
Molar Ratio ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Nickel Ions ◽  
Aqueous Effluents ◽  
Removal Of Metal Ions ◽  
Phosphonic Acid Groups ◽  
Thermosensitive Copolymers

In this work, new thermosensitive copolymers bearing phosphonated groups were synthesized and used to remove metal pollution. Sorption properties are brought by hydrolyzed (dimethoxyphosphoryl)methyl 2-methylacrylate (hMAPC1) monomer. N-n-propylacrylamide (NnPAAm) led to the thermoresponsive properties of the copolymers. Low lower critical solution temperature (LCST) values were observed, ranging between 20 and 25 °C depending on the molar ratio of each monomer in the copolymer. Sorption properties of these copolymers towards nickel ions were evaluated for increasing temperatures (10–40 °C), Ni ion concentrations of 20 mg L−1 and pH values between 3 and 7. Best results were observed for temperatures just lower than the LCST (20 °C), when the copolymer was fully soluble in water solution. For temperature higher than the LCST, phosphonic diacid groups accessibility was considerably reduced by the precipitation of the thermosensitive part of the copolymer leading to lower sorption properties. In these conditions, the highest Ni removal by the copolymer was observed for pH = 7, when there was almost no competition between the sorption of H+ and Ni2+ ions on the phosphonic acid groups. These optimal conditions enabled removal of about 70% of the nickel in the synthetic effluent.

Selective Hydrogen Bonding Controls Temperature Response of Layer-by-Layer Upper Critical Solution Temperature Micellar Assemblies

Soft Matter ◽  
2021 ◽  
Author(s):  
Aliaksei Aliakseyeu ◽  
Victoria Albright ◽  
Danielle Yarbrough ◽  
Samantha Hernandez ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Methacrylic Acid ◽  
Temperature Response ◽  
Solution Temperature ◽  
Layer By Layer ◽  
Critical Solution Temperature ◽  
Hydrogen Bonding Interactions ◽  
Upper Critical Solution Temperature ◽  
Lbl Films

This work establishes a correlation between the selectivity of hydrogen-bonding interactions and the functionality of micelle-containing layer-by-layer (LbL) assemblies. Specifically, we explore LbL films formed by assembly of poly(methacrylic acid)...

scholarly journals Thermo- and Photoresponsive Behaviors of Dual-Stimuli-Responsive Organogels Consisting of Homopolymers of Coumarin-Containing Methacrylate

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 329
Author(s):  
Seidai Okada ◽  
Eriko Sato
Keyword(s):  
Functional Group ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Equilibrium Degree ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Dual Functional ◽  
Wide Range ◽  
Increasing Temperature

Coumarin-containing vinyl homopolymers, such as poly(7-methacryloyloxycoumarin) (P1a) and poly(7-(2′-methacryloyloxyethoxy)coumarin) (P1b), show a lower critical solution temperature (LCST) in chloroform, which can be controlled by the [2 + 2] photochemical cycloaddition of the coumarin moiety, and they are recognized as monofunctional dual-stimuli-responsive polymers. A single functional group of monofunctional dual-stimuli-responsive polymers responds to dual stimuli and can be introduced more uniformly and densely than those of dual-functional dual-stimuli-responsive polymers. In this study, considering a wide range of applications, organogels consisting of P1a and P1b, i.e., P1a-gel and P1b-gel, respectively, were synthesized, and their thermo- and photoresponsive behaviors in chloroform were investigated in detail. P1a-gel and P1b-gel in a swollen state (transparent) exhibited phase separation (turbid) through a temperature jump and reached a shrunken state (transparent), i.e., an equilibrium state, over time. Moreover, the equilibrium degree of swelling decreased non-linearly with increasing temperature. Furthermore, different thermoresponsive sites were photopatterned on the organogel through the photodimerization of the coumarin unit. The organogels consisting of homopolymers of coumarin-containing methacrylate exhibited unique thermo- and photoresponsivities and behaved as monofunctional dual-stimuli-responsive organogels.

scholarly journals Synthesis of a thermoresponsive crosslinked MEO2MA polymer coating on microclusters of iron oxide nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alejandro Lapresta-Fernández ◽  
Alfonso Salinas-Castillo ◽  
Luis Fermín Capitán-Vallvey
Keyword(s):  
Iron Oxide ◽  
Synthesis Temperature ◽  
Water Soluble ◽  
Covalent Attachment ◽  
Solution Temperature ◽  
Tetraethylene Glycol ◽  
Critical Solution Temperature ◽  
Large Size ◽  
Transmission Electron ◽  
Azo Initiator

AbstractEncapsulation of magnetic nanoparticles (MNPs) of iron (II, III) oxide (Fe3O4) with a thermopolymeric shell of a crosslinked poly(2-(2-methoxyethoxy)ethyl methacrylate) P(MEO2MA) is successfully developed. Magnetic aggregates of large size, around 150–200 nm are obtained during the functionalization of the iron oxide NPs with vinyl groups by using 3-butenoic acid in the presence of a water soluble azo-initiator and a surfactant, at 70 °C. These polymerizable groups provide a covalent attachment of the P(MEO2MA) shell on the surface of the MNPs while a crosslinked network is achieved by including tetraethylene glycol dimethacrylate in the precipitation polymerization synthesis. Temperature control is used to modulate the swelling-to-collapse transition volume until a maximum of around 21:1 ratio between the expanded: shrunk states (from 364 to 144 nm in diameter) between 9 and 49 °C. The hybrid Fe3O4@P(MEO2MA) microgel exhibits a lower critical solution temperature of 21.9 °C below the corresponding value for P(MEO2MA) (bulk, 26 °C). The MEO2MA coating performance in the hybrid microgel is characterized by dynamic light scattering and transmission electron microscopy. The content of preformed MNPs [up to 30.2 (wt%) vs. microgel] was established by thermogravimetric analysis while magnetic properties by vibrating sample magnetometry.

A polyelectrolyte-containing copolymer with a gas-switchable lower critical solution temperature-type phase transition

2019 ◽  
Vol 10 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Jin-Jin Li ◽  
Yin-Ning Zhou ◽  
Zheng-Hong Luo ◽  
Shiping Zhu
Keyword(s):  
Phase Transition ◽  
Cloud Point ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Type Phase

A polyelectrolyte-containing copolymer with a CO2/N2-switchable cloud point, resulting from the gas-induced alternation of hydrophilicity, was prepared.

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