Switchable surfaces smart polymers

Thermoresponsive polymers based on oligo(ethylene glycol) acrylates or methacrylates can be easily prepared by atom transfer radical polymerization under straightforward experimental conditions (i.e. in bulk or in ethanol solution and in the presence of commercially available catalysts). Thus, these stimuli-responsive macromolecules can be exploited for preparing a wide range of smart advanced materials such as thermoreversible hydrogels, thermoresponsive block-copolymer micelles and switchable surfaces. Hence, some of the results... 

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... 

Like a bulk responsive material, surface of a substrate can be responsive upon electrochemical, photo, temperature, pH, mechanical, or electrical stimuli (Lahann Langer, 2005). Researchers are developing different ways to make these smart surfaces such as self-assembled monolayers (SAMs), polymer brushes, or copolymer coatings. A classic example is a switchable SAM surface in responsive to electric potential, which achieve hydrophobic-hydrophilic transition on a gold substrate. The switchable surfaces provide an idea platform to smdy surface-biological system interactions (Lahann et al., 2003). Polymer brushes and copolymers are more practical avenues to be applied with long-term performance. 

Very recently a differential pulse voltammetry device has been developed through imprinting smart polymers. In this experiment, which was described by N. Karimian et al, a temperature sensitive amine-terminated poly (N-isopropylacrylamide) block, and (N,N -methylenebisacryl amide) cross-linker with o-phenylenediamine were electropolymerised on the surface of a gold electrode, using folic acid as the template. This led to a thermally switchable MIP sensor with selectivity towards the template [355]. 

Materials or surfaces are said to be responsive if they display a pronounced response to an environmental stimulus, particularly a response that may be suitable for application. Some responses in the form of physical or phase changes can be switchable or reversible. With the development of materials science, especially with the development of synthetic polymers and surface chemistry, these materials and surfaces have been designed for broad applications. Smart or intelligent has also been used to describe these materials since the 1980s. Shape-memory alloys and polymers, piezoelectric materials, and switchable glass are all good examples. 

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