scholarly journals Well-Defined Dual Light- and Thermo-Responsive Rod-Coil Block Copolymers Containing an Azobenzene, MEO2MA and OEGMA

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 284 ◽  
Author(s):  
Changjun Park ◽  
Jaewon Heo ◽  
Jinhee Lee ◽  
Taehyoung Kim ◽  
Sang Youl Kim
Keyword(s):  
Block Copolymers ◽  
Polymeric Micelles ◽  
Solution Temperature ◽  
Chain Growth ◽  
Condensation Polymerization ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Rigid Rod ◽  
Responsive Behavior ◽  
End Group

Here we report the dual light- and thermo-responsive behavior of well-defined rod-coil block copolymers composed of an azobenzene unit, 2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA) and oligo(ethylene glycol) methacrylate (OEGMA). Azobenzene-containing rigid rod blocks prepared by chain growth condensation polymerization of the azobenzene containing monomer were used as a macroinitiator of atom transfer radical polymerization (ATRP) after attaching an α-bromoisobutyryl group as an end group. Synthesis of well-defined rod-coil block copolymers with different coil block lengths was achieved by copolymerization of MEO2MA and OEGMA monomers. The synthesized polymers exhibited amphiphilic properties and polymeric micelles were formed in aqueous solution. The light-responsive behaviors of azobenzene moieties, photoisomerization by irradiation of light, and thermo-responsive behaviors of P(MEO2MA-co-OEGMA) coil blocks, aggregation by increment of temperature over lower critical solution temperature, were investigated. A dual stimuli-responsive behavior of the rod-coil block copolymers was observed when exposed to light and heat.

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 Study on the Effect of 1-Butanol Soluble Lignin on Temperature-Sensitive Gel

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1109 ◽  
Author(s):  
Pan Jiang ◽  
Yi Cheng ◽  
Sheng Yu ◽  
Jie Lu ◽  
Haisong Wang
Keyword(s):  
Environmental Temperature ◽  
Hydroxyl Group ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Stimuli Responsive ◽  
Agricultural Field ◽  
Absorption Properties ◽  
Critical Solution Temperature ◽  
Temperature Sensitive Hydrogel ◽  
Soluble Lignin

A protocol for the fractionation of lignin with 1-butanol as solvent has been proposed in order to improve the utilization of industry alkali lignin. 1-butanol soluble lignin (BSL) was used as a building block for temperature-sensitive hydrogel with N-isopropylacrylamide (NIPAAm) through graft polymerization. The result shows that 1-butanol fractionation is an effective method to improve the molecular weight homogeneity of lignin (PDI, 2.5 to 1.83) and increase the hydroxyl group content (0.585–1.793 mmol/g). The incorporation of BSL into the temperature-sensitive hydrogel can enhance the thermal stability and increase the hydrophobicity of the gel, which leads to a decrease in lower critical solution temperature (LCST). In addition, the compression strength, swelling ratio, and pore size of the gel can be adjusted by the dosage of lignin. This stimuli-responsive gel, with an LCST around 32 °C, is expected to be applied in the agricultural field as a pesticide carrier by stimulating release and absorption properties based on the change in natural environmental temperature.

scholarly journals Multiresponsive micellar block copolymers from 2-vinylpyridine and dialkylvinylphosphonates with a tunable lower critical solution temperature

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78750-78754 ◽  
Author(s):  
F. Adams ◽  
P. T. Altenbuchner ◽  
P. D. L. Werz ◽  
B. Rieger
Keyword(s):  
Block Copolymers ◽  
Lower Critical Solution Temperature ◽  
Ph Sensitivity ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Temperature Range

Tailor-made, multi-responsive micellar AB and ABB′ block copolymers show a pH-sensitivity and a tunable LCST within an expanded temperature range.

Pyrene-labeled amphiphilic poly-(N-isopropylacrylamides) prepared by using a lipophilic radical initiator: synthesis, solution properties in water, and interactions with liposomes

1995 ◽  
Vol 73 (11) ◽  
pp. 2030-2040 ◽  
Author(s):  
Françoise M. Winnik ◽  
Alexander Adronov ◽  
Hiromi Kitano
Keyword(s):  
Polymeric Micelles ◽  
Polymer Concentration ◽  
Polymer Chains ◽  
Solution Temperature ◽  
Solution Properties ◽  
Excimer Emission ◽  
Elastic Light Scattering ◽  
Critical Solution Temperature ◽  
Liposome Suspension ◽  
Hydrophobic Tail

Fluorescently labeled amphiphilic poly-(N-isopropylacrylamides) (PNIPAM) substituted with a N-[4-(1-pyrenyl)butyl]-N-n-octadecyl group at the chain end were prepared by free-radical polymerization in dioxane of N-isopropylacrylamide (NIPAM) using 4,4′-azobis{4-cyano-N,N-[4-(1-pyrenyl)butyl]-n-octadecyl}pentanamide as the initiator. The solution properties of the polymers in water were studied as a function of polymer concentration and temperature. Quasi-elastic light-scattering measurements and fluorescence experiments monitoring the pyrene excimer and pyrene monomer emissions revealed the presence of multimolecular polymeric micelles below the lower critical solution temperature (LCST) of PNIPAM. These underwent partial, reversible reorganization as they were heated above the LCST. The interactions of the pyrene-labeled amphiphilic PNIPAM with dimyristoylphosphatidylcholine (DMPC) liposomes have been examined in water at 25 °C. From fluorescence experiments it was established that the polymeric micelles are disrupted irreversibly upon contact with the liposomes. The anchoring of the polymer chains occurs by insertion of their hydrophobic tail within the phospholipidic bilayer, as evidenced from a large decrease of the pyrene excimer emission relative to pyrene monomer emission. The copolymers remained anchored within the bilayer as the temperature of the copolymer–liposome suspension was raised above the LCST of PNIPAM. Keywords: liposome, poly-(N-isopropylacrylamide), fluorescence, micelles.

Anthracene functionalized thermosensitive and UV-crosslinkable polymeric micelles

2015 ◽  
Vol 6 (11) ◽  
pp. 2048-2053 ◽  
Author(s):  
Yang Shi ◽  
Renata M. Cardoso ◽  
Cornelus F. van Nostrum ◽  
Wim E. Hennink
Keyword(s):  
Aqueous Solution ◽  
Block Copolymer ◽  
Lower Critical Solution Temperature ◽  
Polymeric Micelles ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Uv Illumination ◽  
Uv Lamp

An anthracene-functionalized thermosensitive block copolymer was synthesized, which formed micelles by heating its aqueous solution above the lower critical solution temperature (LCST). The micelles were subsequently crosslinked by UV illumination at 365 nm with a normal handheld UV lamp.

scholarly journals How to manipulate the upper critical solution temperature (UCST)?

2017 ◽  
Vol 8 (1) ◽  
pp. 220-232 ◽  
Author(s):  
Jukka Niskanen ◽  
Heikki Tenhu
Keyword(s):  
Aqueous Solutions ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Ph Influence ◽  
Counter Ions ◽  
Upper Critical Solution Temperature

In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers.

scholarly journals Smart, Naturally-Derived Macromolecules for Controlled Drug Release

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1918
Author(s):  
Izabela Zaborniak ◽  
Angelika Macior ◽  
Paweł Chmielarz
Keyword(s):  
Smart Materials ◽  
Phase Transfer ◽  
Controlled Drug Release ◽  
Polymer Chains ◽  
Solution Temperature ◽  
Hydrodynamic Diameter ◽  
Ph Responsive ◽  
Critical Solution Temperature ◽  
Vis Spectroscopy ◽  
Responsive Behavior

A series of troxerutin-based macromolecules with ten poly(acrylic acid) (PAA) or poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) homopolymer side chains were synthesized by a supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) approach. The prepared precisely-defined structures with low dispersity (Mw/Mn < 1.09 for PAA-based, and Mw/Mn < 1.71 for PDMAEMA-based macromolecules) exhibited pH-responsive behavior depending on the length of the polymer grafts. The properties of the received polyelectrolytes were investigated by dynamic light scattering (DLS) measurement to determine the hydrodynamic diameter and zeta potential upon pH changes. Additionally, PDMAEMA-based polymers showed thermoresponsive properties and exhibited phase transfer at a lower critical solution temperature (LCST). Thanks to polyelectrolyte characteristics, the prepared polymers were investigated as smart materials for controlled release of quercetin. The influence of the length of the polymer grafts for the quercetin release profile was examined by UV–VIS spectroscopy. The results suggest the strong correlation between the length of the polymer chains and the efficiency of active substance release, thus, the adjustment of the composition of the macromolecules characterized by branched architecture can precisely control the properties of smart delivery systems.

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