- Systematic structure control of ammonium iodide salts as feasible UCST-type forward osmosis draw solutes for the treatment of wastewater
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A variety of UCST-type thermoresponsive ammonium iodide salts is systematically designed and synthesised with desired aqueous solubility, phase-transition temperature, osmolality change, phase-transition concentration range, stability, and toxicity by controlling the ionic interactions, hydrophobicity, and symmetry of the salt structure. Suitable draw solutes can be selected based on the characteristics of the ammonium iodide salts as well as the feed solutions for feasible forward osmosis (FO)-based water purification. In this research, highly concentrated wastewater from a flue gas desulfuriser (FGD), with osmotic pressure three times higher than seawater, is targeted for purification by FO using the draw solutes. Two ammonium iodide salts (HM8I and HM10I) show a remarkable water flux from the wastewater samples and significantly lower salt leakage compared to conventional draw solutes. The osmolality of the phase-separated draw solution drops to less than one tenth of that of the initial feed solution, and reverse osmosis or nanofiltration can be applied to the solution with much lower external pressure for the final purification to produce fresh water. This systematic approach to the design and selection of suitable draw solutes can be an effective strategy for future practical FO-based wastewater treatment and seawater desalination.
- Park, Jeongseon,Joo, Heeyoung,Noh, Minwoo,Namkoong, Yon,Lee, Seonju,Jung, Kyung Hwa,Ahn, Hye Ryun,Kim, Seulah,Lee, Jong-Chan,Yoon, Jae Hoon,Lee, Yan
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supporting information
p. 1255 - 1265
(2018/02/06)
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- Polycations. 19. The synthesis of symmetrical dicationic lipids with internal dimethylazonia functionalities separated by a spacer unit and pendant chains
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Herein is reported the preparation of several series of symmetrical polyammonium salts that serve as cationic lipids or precursors thereof, and are structurally based on several series of parent diamines where dimethylazonia functionalities are present, separated by a central structural unit, and pendant terminal chains. The resultant materials are of significant interest for a variety of purposes, such as serving as antihydrophobic species and as transfectins, the details of which are provided in separate reports. Attempts to effect selective alkylation to provide the corresponding unsymmetrical cationic lipids were without success, always leading to relatively useless mixtures of products.
- Engel, Robert,Rizzo, JaimeLee Iolani,Montenegro, Diego,Leb, Jay,Coleman, Delroy,Hong, Carolyn,Jeanty, Herby,Thomas, Marie
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experimental part
p. 105 - 108
(2010/04/05)
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- A convenient synthesis of [11C]paraquat and other [N-methyl-11C]bisquaternary ammonium compounds
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[11C]Paraquat was synthesized by the reaction of [11C]methyl triflate with the mono-triflate salt of 1-methyl-[4,4′]bipyridinyl. The product was selectively separated from the precursor by a microcolumn of Chelex 100 ion exchange resin. The method was applied to the synthesis of a variety of [N-methyl-11C]bisquaternary ammonium compounds. This is the first reported use of a chelating cation exchange resin for the selective purification of organic dications. Copyright
- Jewett, Douglas M.,Kilbourn, Michael R.
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p. 281 - 289
(2007/10/03)
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- DNA Interactions with Porphyrins Bearing Ammonium Side Chains
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Eleven new porphyrins bearing either tertiary amine or ammonium groups with different spacers in the meso position have been synthesized.Five of them were water-soluble enough for DNA binding studies.UV/vis measurements of some derivatives as a function of pH quantifies the porphyrin core protonation postulated recently by Marzilli et al. with an uptake of two protons and pK values of 6.0 or 6.4, respectively.The porphyrins as well as their Cu(II) or Zn(II) derivatives decrease the viscosity of ds(CT) DNA slightly and increase the melting point of DNA by only up to 1.7 deg C at DNA base pair/ligand ratios of 40.DNA causes either a red shift (/= -7 nm) of the Soret bands.These results as well as the observed small hypochromicities show that all new porphyrins interact with DNA without intercalation.However, their affinity in comparison with other macrocycles bearing four positive charges is, based on ethidium bromide assays with C50 values of 7E-8 to 2E-7 M relatively high and points to groove binding contributions by other than electrostatic forces.
- Schneider, Hans-Joerg,Wang, Manxue
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p. 7473 - 7478
(2007/10/02)
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