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Showing 1 to 20 of 33 for “"lower critical solution temperature (LCST)"”.
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Syntax of Phase Transition Peptide Polymers with LCST and UCST Behavior
… a soluble to insoluble phase transition at temperatures above a lower critical solution temperature (LCST) or below an upper critical solution temperature (UCST). We show that this syntax ranges from phase transition polymers composed of simple repeats of a few amino acids to polymers whose …
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Factors Affecting Size and Swelling of Poly(ethylene glycol) Hydrogel Microspheres Formed in Aqueous Sodium Sulfate Solutions
The lower critical solution temperature: LCST) behavior of poly(ethylene glycol): PEG) in aqueous sodium sulfate solutions was exploited to fabricate hydrogel microspheres under mild conditions without the use of other monomers, polymers, surfactants or organic solvents. Reactive PEG derivatives …
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Development and Characterization of Reagent Pencils for Microfluidic Paper Based Analytical Devices
… (PNIPAM) was developed. In this work, PNIPAM’s lower critical solution temperature (LCST) was manipulated with various salt solutions to control fluid flow both laterally and vertically through various microPAD designs. It was found that, while PNIPAM successfully blocked or retarded fluid flow …
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Synthesis and characterization of tethered poly(n-isopropylacrylamide) for quantitative cell adhesion studies
… its relative hydrophobicity above and below its lower critical solution temperature (LCST ~ 32\uf0b0C). This thesis reports on grafted PNIPAAm brushes, synthesized using a relatively simple and rapid method which allows atom transfer radical polymerization (ATRP) in presence of air. In this study …
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Thermoresponsive Glycopolymers via Controlled Radical Polymerization (RAFT) for Biomolecular Recognition
… of the most widely studied polymers due to its lower critical solution temperature (LCST) at ~ 32° C in aqueous solution. Additionally, glycopolymers, where free sugar units are present, have potentially interesting applications especially in bio-recognition where sugars play an important role. …
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Development of functional hydrogels for sensor applications
… glycol methacrylates. This allows to tune the lower critical solution temperature (LCST) of the polymers in aqueous media. The molar masses are variable thanks to the excurse taken in polymerization in ionic liquids thus stretching molar masses from 25 to over 1000 kDa. The systems that were …
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Intrinsically Disordered Protein Polymer Libraries as Tools to Understand Protein Hydrophobicity
… and aliphatic amino acids, have observable lower critical solution temperature (LCST) phase transition behavior at physiologically relevant temperature and concentration ranges. This behavior is a striking feature of disordered proteins in nature, where chemical or physical stimuli lead to …
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Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide)
… using thermal inkjet printing of a prepolymer solution and subsequent polymerization using UV irradiation. When the gel is swollen, it blocks flow from passing through the channel. Upon heating, the gel shrinks and allows flow in the channel. Poly(NIPAAm) is a thermosensitive hydrogel that …
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Functional and responsive surfaces via initiated chemical vapor deposition (iCVD)
… through the use of an external stimulus, such as temperature, pH, or electric fields among others. Temperature-responsive polymers, especially those based on N-isopropylacryalmide (NIPAAm), are of particular research interest due the ease of implementation of temperature changes to systems as well …
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Evaluating bacterial cell immobilization matrices for use in a biosensor
… matrix for the bacteria; however its high lower critical solution temperature (LCST) of ~33oC is problematic for typical, ambient applications. Another thermally reversible copolymer, N-isopropylacrylamide-co-N-acryloyl-6-amino caproic acid (NIPA-co-AcACA) was synthesized; however, it did …
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Fabrication and light scattering study of multi-responsive nanostructured hydrogels and water-soluble polymers.
… into the PNIPAM network. The semi-dilute aqueous solutions of the PNIPAM-PAAc IPN microgels exhibit an inverse thermo-reversible gelation. Furthermore, IPN microgels undergo the reversible volume phase transitions in response to both pH and temperature changes associated to PAAc and PNIPAM, …
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Polymer hydrogel nanoparticles and their networks
… bromide) dispersion above the lower critical solution temperature (LCST) of the HPC. The size distributions of microgel particles, measured by dynamic light scattering, have been correlated with synthesis conditions including surfactant concentration, polymer concentration, and …
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A study of inter- and intramolecular interactions through neutron compton scattering and low temperature matrix isolation infrared spectroscopy
… observe changes in momentum distributions in a solution of poly-N-isopropyl acrylamide (pNIPAAm) passing through a temperature-induced phase change, deuterated polymer/ solvent mixtures were studied on the VESUVIO instrument at the ISIS RAL facility, and the analysis of that data is presented. …
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Synthesis, Characterization and Structure-Property Relationships of Polymer-Stabilized Nanoparticles Containing Imaging and Therapeutic Agents
… induced by heating the suspension above the lower critical solution temperature (LCST) of the polymer, and substantial increase in the NMR transverse relaxation rates was noted. Controlled clusters of primary iron oxide nanoparticles stabilized by the biodegradable block copolymer, …
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Kinetic and mechanistic investigations of polyimide formation and characterization of their blends with polybenzimidazoles
… function of reaction conditions. The homogeneous solution imidization processes were described by auto-acid catalyzed second order kinetics. The effects of heteroatom bridging groups in the diamines and dianhydrides on reaction rates have been investigated and a possible reaction mechanism for the …
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Poly(NIPAAm-co-AAm)-gold nanoshell composites for optically-triggered cancer therapeutic delivery
… undergo a physical property transition at their lower critical solution temperature (LCST). When transitioning from below to above the LCST, the hydrogel material expels large amounts of water and absorbed molecules. This phase change can be optically triggered by embedded gold-silica nanoshells, …
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Novel amphiphilic diblock copolymers by RAFT-polymerization, their self-organization and surfactant properties
… copolymers in bulk. The thermodynamic state in solution is found to be in the strong or super strong segregation limit. Nevertheless, due to the low glass transition temperature of the core-forming block, unimer exchange occurs between the micelles. Despite the dynamic character of the polymeric …
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Ratiometric copper(II) indicators based on poly(n-isoproprylacrylamide) and fluorescence resonance energy transfer
… of these two portions. Aggregation above the lower critical solution temperature (LCST) of this copolymer brings about a large increase in fluorescence resonance energy transfer (FRET). Addition of Cu(II) to the aggregated copolymer introduces charge onto the backbone, causing the copolymer to …
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Introduction of a thermo-sensitive non-polar species into polyelectrolyte multilayer capsules for drug delivery
… to be a thermo-sensitive polymer that has a Lower Critical Solution Temperature (LCST) around 32oC; above this temperature PNIPAM is insoluble in water and collapses. It is also known that with the addition of salt, the LCST decreases. This work shows Differential Scanning Calorimetry (DSC) …
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Twofold switchable block copolymers based on new polyzwitterions
… in water, deuterated water, and aqueous salt solutions. These poly(sulfobetaine)s show thermoresponsive behavior in water, exhibiting upper critical solution temperatures (UCST). Phase transition temperatures depend notably on the molar mass and polymer concentration, and are much higher in …
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