Thermo-responsive polymers properties

We hope that this brief review has given the reader a general feeling of the development and application of CE in the separation of nucleic acids. With the advent of capillary array electrophoresis and microchip electrophoresis, as well as remarkable improvements in separation matrices, CE has become a standardized and cost-effective technique in the separation of nucleic acids. Novel thermo-responsive polymer solutions combine the merits of different monomers, and offer the possibility to fine-tune the desirable properties of polymer molecular architecture and chemical composition. Artificial entropic trapping systems obviate the use of viscous polymer solutions, and even offer fast, unattended, miniaturized, and multiplexed platforms. Optimizing the geometry of these electrophoretic systems to both increase the separation and reduce the diffusion (band broadening) is the main topic for future research. 

It would be of interest to add some functionalities such as properties in response to changes in pH, temperature, electrical potential and so on as well as hydrophilic properties to PTFE surfaces by the combined technique just described. Poly(AT-isopropylaoylamide) (PNIPA ) is a well-known thermo-responsive polymer whose hydrogel undergoes a volume change around 31 C in an aqueous solution. And further, poly 2-(dimethylamino)ethyl methacrylate (PDMA) in a pH 10 buffer solution exhibits a drastic decrease in the transmittance around 28 °C, which is considered to come from a phase transition of PDMA chains (ii). Therefore, we have tried to prepare JV -isopropylacrylamide (NIPAAm) or 2-(dimethylamino)ethyl... 

Thermo-responsive materials have huge potential for a suite of applications, owing to their responsiveness to an external trigger and the ability to be used in different formats. There are a variety of thermo-responsive polymers that differ in their mechanism of temperature sensitivity and thereby have different properties. These... 

The most commonly studied thermo-responsive polymers are poly (N-isopropylacrylamide), poly(2-alkyl-2-oxazoline)s, poly(vinyl methyl ether), poly(N-vinyl caprolactam), and polymers of oligoethylene glycol (meth)acrylates. Each of them is characterized with specific LCST, mechanism of heat-driven phase transition, structure and properties of the resulting mesoglobules, as well as with varying extents of reversibility and reproducibility of the process of mesoglobule formation [58]. The most preferable characteristics of the thermo-responsive polymers and mesoglobules used as templates for nanocapsule preparation have been formulated below [58] ... 

Contrary to the monomer-based techniques described so far, low-pressure plasma immobilisation allows to permanently attach stimuli-responsive polymer films with a thickness of a few nanometers on polymeric substrates using an argon discharge. At appropriate treatment parameters, covalent fixation is achieved while important properties of the immobilised polymer like the thermo-responsive behaviour are preserved (Schmaljohann et al. 2004 Nitschke et al. 2004). 

SHT Shtanko, N.I., Lequieu, W., Goethals, E.J., and DuPrez, F.E., pH- and thermo-responsive properties of poly(A-viiwlcaprolactam-co-acrylic acid) copolymers, Polym. Int. 52, 1605, 2003. 

The low recovery stress (<10 MPa) of thermo-responsive SMPs originates from their intrinsically low modulus, in the order of 0.1-1 GPa below the thermal transition temperature. CNTs have proven to enhance the mechanical properties, particularly modulus, of various polymers. ... 

On the other hand, cells and proteins exhibit space- and time-dependent dynamic changes in their conformations and functionalities in the human body. Since the 1990s, dynamic switchable surfaces have been comprehensively studied in order to control the biomolecular dynamics by modification with smart polymers [6], which show changes in their conformations and properties in response to external stimuli. Among them, thermo-responsive poly(AT-isopropylacrylamide) (PNlPA/ m) is one of the most successful models to control the interaction between biomolecules and the grafted substrates by temperature... 

Smart colloids are colloidal dispersions for which certain properties, such as size and structure, can be altered by changing an external influence, such as temperature, eg, cross-linked polymer gels of poly(iV-isoproplyaciylamide). Such polymer systems can swell or shrink in response to temperature changes, and are also termed thermo-shrinking polymers. (see References 122-124). 

Glampedaki P, Petzold G, Dutsch V, MillerR, Warmoeskerken MCG (2012) Physicochemical properties of biopolymer-based polyelectrolyte complexes with controlled pH/thermo responsiveness. React Funct Polym 72 458... 

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