In this work, we explore the ability of utilizing hydrogels synthesized from a temperature-sensitive polymer and a polyelectrolyte to desalinate salt water by means of reversible thermally induced absorption and desorption. Thus, the influence of the macromolecular architecture on the swelling/deswelling behavior for such hydrogels was investigated by tailor-made network structures. To this end, a series of chemically cross-linked polymeric hydrogels were synthesized via free radical-initiated copolymerization of sodium acrylate (SA) with the thermoresponsive comonomer N-isopropylacrylamide (NIPAAm) by realizing different structural types. In particular, two different polyNIPAAm macromonomers, either with one acrylate function at the chain end or with additional acrylate functions as side groups were synthesized by controlled polymerization and subsequent polymer-analogous reaction and then used as building blocks. The rheological behaviors of hydrogels and their estimated mesh sizes are discussed. The performance of the hydrogels in terms of swelling and deswelling in both deionized water (DI) and brackish water (2 g/L NaCl) was measured as a function of cross-linking degree and particle size. The salt content could be reduced by 23% in one cycle by using the best performing material.

Because of the success of dyeing synthetic fibers with disperse dyes in supercritical carbon dioxide, we have investigated the possibility of dyeing natural fibers with this technique. Experiments are presented for wool and cotton dyeings after a special pretreatment.

Although current desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. We have previously reported that reversible thermally induced sorption/desorption process using polymeric hydrogels hold promise for water desalination with further development. In order to develop a more effective hydrogels architecture, polyelectrolyte moieties were introduced in this work as pendent chains and a thermally responsive polymer as network backbone using reversible addition-fragmentation chain transfer (RAFT) polymerisation. The ability of the comb-type polymeric hydrogels to desalinate water was evaluated. These hydrogels were proved to absorb water with low salinity from brine solution of 2 g L −1 NaCl and release the absorbed water at relatively low temperature conditions of 50 • C. The fraction of the grafted polyacrylic acid and the comb-chain length were varied to understand their influence on the swelling/deswelling behaviour for these hydrogels. The ionic fraction in the hydrogels and the resulting hydrophilic/hydrophobic balance are crucial for the proposed desalination process. In contrast, the comb-chain length impacted the swelling behaviour of hydrogels but showed relatively little influence on the dewatering process.

In this work, a pioneering study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM) has been demonstrated.

Here, we synthesize zwitterionic polymer brushes on polyester fabrics by atom transfer radical polymerization (ATRP) after a prefunctionalization step involving an aminolysis reaction with ethylenediamine. Aminolysis is an easy method to achieve homogeneous distributions of functional groups on polyester fibers (PET) fabrics. Varying the polymerization time and the prefunctionalization conditions of the reaction, it is possible to tune the amount of water retained over the surface and study its effect on protein adhesion. This study revealed that the polymerization time plays a major role in preventing protein adhesion on the PET surface.Polymers 2020, 12, 6 2 of 15 interactions between a surface and a bacteria cell envelope [12]. In addition, steric hindrance plays an important role in avoiding protein adhesion, which is a reason why not all hydrophilic surfaces are able to prevent fouling [13][14][15]. Functionalization by polymers implies either a surface grafting of the polymer on a surface (grafting to) or a polymerization using a "grafting from" approach. The latter is often preferred when a better control over grafting density is needed [16][17][18][19][20][21][22][23].Among all polymers, polyethylene glycol (PEGs) and zwitterionic polymers proved to be highly effective against the adhesion of foulants, since several coatings that prevent the attachment of proteins and bacteria have already been synthesized [24,25]. PEG and PEG derivatives were widely used in many applications, including implantable surfaces or the functionalization of nanoparticles (NPs) for drug delivery, where these systems could prolong the blood circulation time [26][27][28][29][30][31][32][33][34][35][36]. However, oxidative damage of PEGylated surfaces and PEG's non-biodegradability represents a major concern and limits its use to short-term applications [37].On the other hand, zwitterionic polymers proved to be very promising for such applications. Zwitterions are neutral but charged molecules containing both a positively and a negatively charged site [38,39]. This charge separation results in a pronounced hydration effect due to the strong interactions with water molecules [25,40].Among zwitterionic polymers, sulfobetaine methacrylate (SBMA) polymers showed low fouling properties and have attracted considerable attention also due to an upper critical solution temperature (UCST) behavior [41][42][43][44][45][46][47].The importance of realizing such antifouling surfaces extends to textile materials as well. For example, textiles used in filtration systems are extensively compromised by fouling, which lowers their durability and requires them to be replaced at short-term distances. Among all fibers, polyester fibers (PET) are broadly used because of their good workability and low price. In addition, it is possible to control filtrations properties by the fiber diameter, the mesh size, and the absolute material thickness [48]. The functionalization of polyester is very demanding due to its lack of functional groups within the polymer ...