## 1 Introduction  
Surface properties of polymer particles or flat surfaces have been one of the most important contributors to their application, especially when the application involves the interaction of these surfaces with foreign media or entities. As an example, the surface properties are of tremendous importance in the chromatographic separations of proteins, polymers or any mixtures. There is always a requirement or desire to achieve extra functionalization on the surface by controlling the surface properties, which can be used for either one application or another or a combination of a few [1,2]. These functionalized surfaces represent a novel class of materials, which at the forefront of technology can lead to revolutionary changes in conventional processes. In one such approach, environmentally responsive character has been generated on the surfaces. Generation of this property on the surface of the materials leads to functionalized materials in which their nature e.g., hydrophobicity or hydrophilicity can be finely controlled by environmental stimulants like temperature, salt, pH, _etc_. This property translates into the use of these materials in a number of applications like temperature controlled adsorption and desorption of biomolecules, temperature controlled drug delivery processes, _etc_. Different ways to generate the thermal responsive behavior on the surfaces have been developed, different materials to generate thermal responsiveness have been used and different substrates on which thermal responsive character has been achieved have been used. Many techniques to functionalize the surfaces have been reported in the literature, like physical adsorption of oligomeric or polymeric chains on the surface [3-5], grafting of polymer chains 'to' the surface [6,7] and grafting of polymer chains 'from' the surface [8,9]. Though physical adsorption has an advantage that it can lead to the adsorption of long polymer chains of well defined length, molecular weight distribution and composition to the surface, this approach suffers from the limitations of steric hindrance posed by the long polymer chains, thus seriously limiting the final surface density of the grafts. Apart from that, as the chains are only physically bound to the surfaces, the efficiency of these linkages for load transfer or resistance towards washing or cleaving off may not be sufficient. Grafting of polymer chains 'to' the surface approach focuses on chemical immobilization of end-functionalized polymer chains to the surface by reacting the ends with the reactive groups already immobilized on the surface. It can also be achieved either by attaching a monomer on the surfaces and subsequently polymerizing the monomer in the presence of externally added monomer and initiator. In both the cases, as the preformed long chains approach the surfaces, therefore, the steric hindrance concerns may still hinder the generation of high density grafts on the surface. The generated grafts may also not be very uniform in terms of molecular weight and chain lengths _etc_. owing to the uncontrolled nature of the process which is generally achieved by non-living conventional free radical polymerization. Another important and extensively studied approach is the grafting of polymer chains 'from' the surface. In this approach, an initiator is covalently bound to the surface which is subsequently polymerized with the external monomer without the external addition of any further initiator. This approach has enjoyed more success because of its ability to generate densely packed polymer functionalities in the absence of any kinetic hindrance along with the advantage of covalently bound polymer chains on the surface [8-11]. Such structures are referred to as polymer brushes, when the distance between the grafted chains is less than twice the radius of gyration of the unperturbed polymerchain [12].