Ali Wael, Gebert Beate, Altinpinar Sedakat, Mayer-Gall Thomas, Ulbricht Mathias, Gutmann Jochen S, Graf Karlheinz
Physikalische Chemie and CENIDE (Center for Nanointegration), Universität Duisburg-Essen, Universitätsstr. 2, 45141 Essen, Germany.
Deutsches Textilforschungszentrum Nord-West gGmbH, Adlerstr. 1, 47798 Krefeld, Germany.
Polymers (Basel). 2018 May 23;10(6):567. doi: 10.3390/polym10060567.
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.
尽管当前的海水淡化技术已经足够成熟和先进，但淡水短缺仍然被视为全球最紧迫的问题之一。因此，人们强烈希望探索和研究低能耗的新潜在方法。我们之前报道过，使用聚合物水凝胶的可逆热诱导吸附/解吸过程在进一步发展后有望用于海水淡化。为了开发更有效的水凝胶结构，在这项工作中，通过可逆加成-断裂链转移（RAFT）聚合反应，将聚电解质部分作为侧链引入，并使用热响应聚合物作为网络主链。评估了梳型聚合物水凝胶的海水淡化能力。这些水凝胶被证明能够从2 g L - 1 NaCl的盐水溶液中吸收低盐度的水，并在50 ∘C的相对低温条件下释放吸收的水。改变接枝聚丙烯酸的比例和梳链长度，以了解它们对这些水凝胶的溶胀/去溶胀行为的影响。水凝胶中的离子比例以及由此产生的亲水/疏水平衡对于所提出的海水淡化过程至关重要。相比之下，梳链长度影响水凝胶的溶胀行为，但对脱水过程的影响相对较小。
