Microwave-Induced Chain Transfer Polymerization of a Stimuli-Responsive Polymer and Determination of Its Critical Solution Temperature

2006 ◽  
Vol 83 (3) ◽  
pp. 447 ◽  
Author(s):  
R. Freitag ◽  
F. Fischer
Keyword(s):  
Chain Transfer ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer ◽  
Chain Transfer Polymerization

scholarly journals Surface Modification of Silicon Nanowire Based Field Effect Transistors with Stimuli Responsive Polymer Brushes for Biosensing Applications

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 274 ◽  
Author(s):  
Stephanie Klinghammer ◽  
Sebastian Rauch ◽  
Sebastian Pregl ◽  
Petra Uhlmann ◽  
Larysa Baraban ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Silicon Nanowire ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Force Microscopy ◽  
Reversible Phase Transition ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer

We demonstrate the functionalization of silicon nanowire based field effect transistors (SiNW FETs) FETs with stimuli-responsive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) and poly(acrylic acid) (PAA). Surface functionalization was confirmed by atomic force microscopy, contact angle measurements, and verified electrically using a silicon nanowire based field effect transistor sensor device. For thermo-responsive PNIPAAM, the physicochemical properties (i.e., a reversible phase transition, wettability) were induced by crossing the lower critical solution temperature (LCST) of about 32 °C. Taking advantage of this property, osteosarcomic SaoS-2 cells were cultured on PNIPAAM-modified sensors at temperatures above the LCST, and completely detached by simply cooling. Next, the weak polyelectrolyte PAA, that is sensitive towards alteration of pH and ionic strength, was used to cover the silicon nanowire based device. Here, the increase of pH will cause deprotonation of the present carboxylic (COOH) groups along the chains into negatively charged COO− moieties that repel each other and cause swelling of the polymer. Our experimental results suggest that this functionalization enhances the pH sensitivity of the SiNW FETs. Specific receptor (bio-)molecules can be added to the polymer brushes by simple click chemistry so that functionality of the brush layer can be tuned optionally. We demonstrate at the proof-of concept-level that osteosarcomic Saos-2 cells can adhere to PNIPAAM-modified FETs, and cell signals could be recorded electrically. This study presents an applicable route for the modification of highly sensitive, versatile FETs that can be applied for detection of a variety of biological analytes.

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 Grafting of a Stimuli Responsive Polymer on Nanolayered Coextruded PS/PCL Films by Surface Initiated Polymerization

2016 ◽  
Vol 301 (7) ◽  
pp. 870-875 ◽  
Author(s):  
Katrina D. Pangilinan ◽  
Al Christopher C. de Leon ◽  
Joey Dacula Mangadlao ◽  
Eric Baer ◽  
Rigoberto C. Advincula
Keyword(s):  
Stimuli Responsive ◽  
Surface Initiated Polymerization ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer

Stimuli-responsive polymer vesicles

Soft Matter ◽  
2009 ◽  
Vol 5 (5) ◽  
pp. 927 ◽  
Author(s):  
Min-Hui Li ◽  
Patrick Keller
Keyword(s):  
Stimuli Responsive ◽  
Polymer Vesicles ◽  
Responsive Polymer ◽  
Stimuli Responsive Polymer

Facile, Template-Free Synthesis of Stimuli-Responsive Polymer Nanocapsules for Targeted Drug Delivery

2010 ◽  
Vol 122 (26) ◽  
pp. 4507-4510 ◽  
Author(s):  
Eunju Kim ◽  
Dongwoo Kim ◽  
Hyuntae Jung ◽  
Jiyeong Lee ◽  
Somak Paul ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Drug Delivery ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
Template Free ◽  
Targeted Drug ◽  
Stimuli Responsive Polymer
Sign in / Sign up

Export Citation Format

Share Document