Stimuli-responsive microgels with cationic moieties: characterization and interaction with E. coli cells

Soft Matter ◽  
2021 ◽  
Author(s):  
Larissa Hussmann ◽  
Thomke Belthle ◽  
Dan E. Demco ◽  
Radu Fechete ◽  
Andrij Pich
Keyword(s):  
Phase Transitions ◽  
Functional Group ◽  
Stimuli Responsive ◽  
E Coli ◽  
Volume Phase ◽  
Positively Charged

Poly-N-vinylcaprolactam based microgels with positively charged 1-vinyl-3-methylimidazolium were analyzed by functional group volume phase transitions and morphology. The microgels are antibacterial, due to positive charges in the microgel corona.

scholarly journals Continuous fabrication of multi-stimuli responsive graphene oxide composite hydrogel fibres by microfluidics

RSC Advances ◽  
2017 ◽  
Vol 7 (31) ◽  
pp. 19243-19249 ◽  
Author(s):  
Li Peng ◽  
Yan Liu ◽  
Jinghua Gong ◽  
Kaihuan Zhang ◽  
Jinghong Ma
Keyword(s):  
Graphene Oxide ◽  
Phase Transitions ◽  
Composite Hydrogel ◽  
Stimuli Responsive ◽  
Oxide Composite ◽  
Volume Phase ◽  
Spinning Process ◽  
Continuous Fabrication

Stimuli responsive graphene oxide composite hydrogel fibres were preparedviaa microfluidic spinning process, and exhibit both thermo-triggered volume-phase transitions and electrically triggered bending behaviours.

scholarly journals Dual stimuli-responsive oligo(ethylene glycol)-based microgels: insight into the role of internal structure in volume phase transitions and loading of magnetic nanoparticles to design stable thermoresponsive hybrid microgels

2016 ◽  
Vol 7 (2) ◽  
pp. 350-363 ◽  
Author(s):  
Mohamed Boularas ◽  
Elise Deniau-Lejeune ◽  
Valérie Alard ◽  
Jean-François Tranchant ◽  
Laurent Billon ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Magnetic Nanoparticles ◽  
Ethylene Glycol ◽  
Internal Structure ◽  
Stimuli Responsive ◽  
Volume Phase ◽  
Insight Into ◽  
Hybrid Microgels

Design of multi-responsive biocompatible P(MEO2MA-co-OEGMA-co-MAA) microgels and their hybrid magnetic couterparts.

Azulene as an ingredient for visible-light- and stimuli-responsive photoswitches

2021 ◽  
Author(s):  
Andrey G. Lvov ◽  
Aleksei Bredihhin
Keyword(s):  
Visible Light ◽  
Functional Group ◽  
Unique Combination ◽  
Stimuli Responsive

The azulene molecule features an unique combination of optical, luminescent, and stimuli-responsive properties. This makes the azulene motif a promising functional group to be introduced in photoswitches. Recent challenges in...

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 Wave onset in central gray matter - its intrinsic optical signal and phase transitions in extracellular polymers

2001 ◽  
Vol 73 (3) ◽  
pp. 351-364 ◽  
Author(s):  
VERA M. FERNANDES-DE-LIMA ◽  
JOÃO E. KOGLER ◽  
JOCELYN BENNATON ◽  
WOLFGANG HANKE
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Gray Matter ◽  
Action Potentials ◽  
Optical Signal ◽  
Excitable Media ◽  
Extracellular Polymers ◽  
Axon Membrane ◽  
Intrinsic Optical Signal ◽  
Volume Phase

The brain is an excitable media in which excitation waves propagate at several scales of time and space. ''One-dimensional'' action potentials (millisecond scale) along the axon membrane, and spreading depression waves (seconds to minutes) at the three dimensions of the gray matter neuropil (complex of interacting membranes) are examples of excitation waves. In the retina, excitation waves have a prominent intrinsic optical signal (IOS). This optical signal is created by light scatter and has different components at the red and blue end of the spectrum. We could observe the wave onset in the retina, and measure the optical changes at the critical transition from quiescence to propagating wave. The results demonstrated the presence of fluctuations preceding propagation and suggested a phase transition. We have interpreted these results based on an extrapolation from Tasaki's experiments with action potentials and volume phase transitions of polymers. Thus, the scatter of red light appeared to be a volume phase transition in the extracellular matrix that was caused by the interactions between the cellular membrane cell coat and the extracellular sugar and protein complexes. If this hypothesis were correct, then forcing extracellular current flow should create a similar signal in another tissue, provided that this tissue was also transparent to light and with a similarly narrow extracellular space. This control tissue exists and it is the crystalline lens. We performed the experiments and confirmed the optical changes. Phase transitions in the extracellular polymers could be an important part of the long-range correlations found during wave propagation in central nervous tissue.

scholarly journals Single-crystal-to-single-crystal transformations triggered by dehydration in polyoxometalate-based compounds

2018 ◽  
Vol 74 (11) ◽  
pp. 1222-1242 ◽  
Author(s):  
Santiago Reinoso ◽  
Beñat Artetxe ◽  
Juan M. Gutiérrez-Zorrilla
Keyword(s):  
Phase Transitions ◽  
Single Crystal ◽  
Crystal Engineering ◽  
Structural Response ◽  
Transformation Process ◽  
External Stimulus ◽  
Stimuli Responsive ◽  
Feature Article ◽  
Crystal Transformation ◽  
Solvent Molecules

Single-crystal-to-single-crystal transformations are solid-state phase transitions between different crystalline states in which the crystal integrity and the long-range structural order are retained through the whole transformation process. Such a phenomenon constitutes the structural response that some compounds afford when being exposed to a given external stimulus (temperature, pressure, light, etc.) and, therefore, its study has become a relevant focus of interest within crystal engineering because it allows for monitoring how certain properties (colour, magnetism, luminescence, porosity) of the stimuli-responsive material are modified as the structure evolves into the activated form. A range of organic, inorganic and hybrid systems have been found to undergo such phase transitions, but these examples only include a small number of compounds that incorporate polyoxometalate anions, among which the removal of guest solvent molecules (dehydration) stands out as the most common external stimulus able to induce the occurrence of a single-crystal-to-single-crystal transformation. This feature article compiles the examples of dehydration-triggered single-crystal-to-single-crystal transformation studies that have been reported to date for polyoxometalate-based compounds and reviews some of their most relevant structural aspects.

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