nanoparticles hybrid composites for surface-enhanced Raman scattering (SERS)
studies is an interesting application of macroscopic methods to solve application
problems related to stimuli-responsive systems [231]. Finally, it is worth citing
Moghadam and Larson [232], who studied aqueous solutions of hydrophobic drug
molecules (phenytoin) with PNIPAM and its co-polymers to assess its efficacy for
drug delivery applications (effects of the chain length, tacticity, and the
co-monomer content were investigated). The authors noted that: ‘(..) the length and
time scales reachable by atomistic simulations are not sufficient to observe rare
nucleation events and crystal growth nor the effect of polymer on these processes.
Furthermore, even though our results clearly show the collapse of single chains in
aqueous solutions as the temperature increases above the LCST, to understand the
dynamics of gels, which are composed of a complex network of these chains, we
would need to simulate chains containing hundreds of monomers, which is far
beyond the capability of atomistic simulations and would require the development
of coarse-grained models of both polymer and drug, perhaps also using implicit
solvent to increase simulation time/length scale’.
8.6 Outlooks and Perspectives
Currently, stimuli-responsive polymer materials, especially hydrogels, gain a great
attention as potential biomaterials for tissue engineering, drug carriers and
bio-sensors. In this field, the bio-inert systems containing water as a solvent are
mostly demanded. Oligo- and poly (ethylene glycol) and its derivatives (including
POEGMAs), and co-polymers seem to be most attractive. Also, water treatment
technologies important for the environment protection have started to use
stimuli-responsive polymer hydrogels for ion recovery, organic compounds
adsorption and bio-separation. Lenses with a adjustable focal length, attenuators,
micro-valves are examples of technical applications of SRPS. However, some
polymer smart systems have been already commercialized and they are produced at
the industrial scale. Many interesting fields have been still undiscovered and require
further systematic investigation. The so-called reconfigurable materials have risen
to the forefront here [6, 233]. This new class of materials can change not only the
volume, but also the shape in a controlled manner. This new functionality can be
used to design smart connectors and adhesives, grippers, self-folding (origami)
systems, artificial muscles and attenuators and potentially many other devices.
The creation of smart materials still requires new ways of the synthesis of
polymer systems with a strictly demanded size, shape, functionality and properties.
Currently, a broad range of controlled radical polymerisations, such as many
variants of the atom transfer radical polymerisation (ATRP) or the reversible/
addition fragmentation chain transfer (RAFT) polymerization should be mentioned
here [234–241]. The relatively new approach is the polymerization-induced
self-assembly (PISA) (as an alternative to physical methods of controlled
micro-phase separation of di- and multiblock co-polymers), allowing to create
8 Vibrational Spectroscopy in Analysis of Stimuli-Responsive …
257
studies is an interesting application of macroscopic methods to solve application
problems related to stimuli-responsive systems [231]. Finally, it is worth citing
Moghadam and Larson [232], who studied aqueous solutions of hydrophobic drug
molecules (phenytoin) with PNIPAM and its co-polymers to assess its efficacy for
drug delivery applications (effects of the chain length, tacticity, and the
co-monomer content were investigated). The authors noted that: ‘(..) the length and
time scales reachable by atomistic simulations are not sufficient to observe rare
nucleation events and crystal growth nor the effect of polymer on these processes.
Furthermore, even though our results clearly show the collapse of single chains in
aqueous solutions as the temperature increases above the LCST, to understand the
dynamics of gels, which are composed of a complex network of these chains, we
would need to simulate chains containing hundreds of monomers, which is far
beyond the capability of atomistic simulations and would require the development
of coarse-grained models of both polymer and drug, perhaps also using implicit
solvent to increase simulation time/length scale’.
8.6 Outlooks and Perspectives
Currently, stimuli-responsive polymer materials, especially hydrogels, gain a great
attention as potential biomaterials for tissue engineering, drug carriers and
bio-sensors. In this field, the bio-inert systems containing water as a solvent are
mostly demanded. Oligo- and poly (ethylene glycol) and its derivatives (including
POEGMAs), and co-polymers seem to be most attractive. Also, water treatment
technologies important for the environment protection have started to use
stimuli-responsive polymer hydrogels for ion recovery, organic compounds
adsorption and bio-separation. Lenses with a adjustable focal length, attenuators,
micro-valves are examples of technical applications of SRPS. However, some
polymer smart systems have been already commercialized and they are produced at
the industrial scale. Many interesting fields have been still undiscovered and require
further systematic investigation. The so-called reconfigurable materials have risen
to the forefront here [6, 233]. This new class of materials can change not only the
volume, but also the shape in a controlled manner. This new functionality can be
used to design smart connectors and adhesives, grippers, self-folding (origami)
systems, artificial muscles and attenuators and potentially many other devices.
The creation of smart materials still requires new ways of the synthesis of
polymer systems with a strictly demanded size, shape, functionality and properties.
Currently, a broad range of controlled radical polymerisations, such as many
variants of the atom transfer radical polymerisation (ATRP) or the reversible/
addition fragmentation chain transfer (RAFT) polymerization should be mentioned
here [234–241]. The relatively new approach is the polymerization-induced
self-assembly (PISA) (as an alternative to physical methods of controlled
micro-phase separation of di- and multiblock co-polymers), allowing to create
8 Vibrational Spectroscopy in Analysis of Stimuli-Responsive …
257