A series of carboxyethyl amine sodium salts (CASSs) with different carboxyl group numbers are synthesized as draw solutes for forward osmosis (FO) application. Their chemical structures are examined by 1 HNMR and HRMS. FO performances are investigated and compared in terms of different physicochemical properties. The effects of the CASS concentration on the osmotic pressure and viscosity of the draw solutions, as well as the resulted FO performance are also systematically investigated. A high water flux of 23.07 LMH and an acceptable reverse salt flux of 0.75 gMH can be achieved with 0.5 g mL 21 triethylenetetramine hexapropionic acid sodium (TTHP-Na) draw solution under PRO mode, which is superior to most other draw solutes reported in previous literatures. TTHP-Na draw solution is further evaluated to recycle the Congo red solution via FO process to examine its applicability for waste water treatment.

In this study, synergetic and controlled-release low-density polyethylene (LDPE) antioxidant active films were prepared by cast extrusion. A well-ordered (4 nm) Mobil Composition of Matter No. 41 (MCM-41) was prepared to carry α-tocopherol for reducing the diffusivity (D), while improving the D of quercetin. Characterization of MCM-41 included small angle X-ray scattering, scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption/desorption testing. New films added α-tocopherol and α-tocopherol loaded with MCM-41 on the base of a LDPE film containing quercetin. Testing of new films covered the physical properties, release behavior, and 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging assays. The physical properties discussed differences among any additives, which contain mechanical and barrier properties. Release experiments showed the controlled-release of MCM-41 to α-tocopherol, while addition of α-tocopherol promoted the release of quercetin in food simulant (95% ethanol). Free radical scavenging increased obviously after adding α-tocopherol and α-tocopherol loaded with MCM-41. This study demonstrated the feasibility of synergetic and controlled-release antioxidant active packaging films. Practical ApplicationThis work provides a method to control the release of α-tocopherol in the packaging films using molecular sieve MCM-41, and promotes the release of quercetin. The preservation of easily oxidized fatty foods is very important. In addition to the usual high-barrier composite packaging, the release-type antioxidant packaging is also a method. Food antioxidant packaging film is an important research direction in the field of intelligent packaging, and has great potential in the field of food flexible packaging. Release-type antioxidants are added to the packaging substrate, and the release rate of antioxidants is adjusted to prevent the oxidation of contents, to extend the shelf life of butter, and other commodities in the process of commodity storage and transportation.

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Abstract:Osmotic energy, as a sustainable energy source with little environmental impact, has drawn much attention in both academia and industry in recent years. Osmotically driven membrane processes can harvest the osmotic energy and thus have great potential to produce sustainable clean water or electric energy. The draw solution, as an osmotic component, has been more and more explored by scientists in recent years in order to achieve a high osmotic pressure and suitable molecular size. In this work, a novel draw solute-sodium tetraethylenepentamine heptaacetate (STPH)-is synthesized and identified by nuclear magnetic resonance spectroscopy ( 1 H-NMR) and Fourier transform infrared (FTIR). Its solution properties are optimized in terms of the solution pH and concentration, and related to the forward osmosis (FO) performance. A water flux of 28.57 LMH and a low solute flux of 0.45 gMH can be generated with 0.5 g/mL STPH draw solution and de-ionized water (DI water) as the feed solution under pressure retarded osmosis (PRO) mode, which is superior to the FO performance with many other draw solutes reported. Further FO desalination test shows a stable water flux of 9.7 LMH with 0.3 g/mL STPH draw solution and 0.6 M NaCl feed solution. In addition, the draw solution recovery is also investigated.

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