Low temperature desiccants in atmospheric water generation.

Surging global water demand as well as changes to weather patterns and over exploitation of natural water sources, such as ground water, has made potable water a critical resource in many parts of the World already – one rapidly heading towards a crisis situation. Desalination has been adopted as a solution – this is however energy intensive and impractical for most of the developing countries - those most in need of water. A renewable source of energy is solar thermal and solar photovoltaic. A plentiful source of water is the humidity in the atmosphere. This research is to push the envelope in pairing these two facts in solving the ‘water problem’, in the use of existing humidification/dehumidification (HDH) systems using solid desiccants. Solar thermal, notably the simple & affordable systems, do not deliver the high temperature that current HDH systems need. Again, the design of the current HDH systems are better suited for steady state, or near steady state, conditions. Solar energy, as well as atmospheric temperature and humidity, are extremely dynamic and independently variable. The existing desiccants have been found to be the limiting factor in building affordable, simple & maintenance free solar thermal powered HDH systems. The result of this study identifies a promising new lithium oxide nano material that meets or exceeds the specifications for such a desiccant. Specifically, Lithium Aluminate (LiAlO2) nano powder, synthesized using a UofL patented process, was found to be have ultra-fast kinetics (of the order of 2-5 minutes for adsorption as well as desorption), low temperature desorption (60-80oC) and low cost ($20/kg). As a spin-off benefit, a validated system was also built that handles the dynamic environmental factors that such an HDH system will need to manage in real-world installations

Preparation and mechanical properties of Nanoclay-MWCNT/Epoxy hybrid nanocomposites

[EN] Among the various kinds of reinforcing element, Multi Wall Carbon Nano-tubes (MWCNT) and Nanoclay have found much more attention as a filler element to upgrade the mechanical properties of polymer composite material. In this paper, production of hybrid nanocomposites and the effect of MWCNT and nanoclay on mechanical properties of hybrid nanocomposites have been evaluated. In hybrid nanocomposites, MWCNT and nanoclay are embedded in epoxy resin. The processing of hybrid nanocomposite is always been a difficult task for researcher to prepare defects free samples. Here, the processing of Epoxy/Nanoclay-MWCNT hybrid composites has been done by using homogenizer and ultrasonic techniques for complete dispersion of nanoparticles into epoxy resin. The MWCNT and nanoclay were embedded into epoxy resin in different weight fractions and mixtures were used for tensile test and hardness specimen production. The tensile modulus and tensile strength values have been calculated via tensile tests. The test result shows that tensile modulus of samples increases as the filler content increase up to certain extent but then start decreasing. Also the elongation reduces as the filler content rises in the epoxy which shows the brittleness present in the samples. Rockwell hardness on B-scale was conducted on Nanocomposite samples and found that increasing the filler content excessively does not improve hardness as much.Kumar, S.; Gupta, A. (2021). Preparation and mechanical properties of Nanoclay-MWCNT/Epoxy hybrid nanocomposites. Journal of Applied Research in Technology & Engineering. 2(1):17-21. https://doi.org/10.4995/jarte.2021.14239OJS172121Alsafee, A.B., Al-ajaj, I.A., Khalili, A.S. (2014). Concentration effect of multi walled carbon nanotube on mechanical properties of epoxies composites. 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Enhanced thermal stability and structural characteristics of different MMT-clay/epoxy-nanocomposite materials. Polymer Degradation and Stability, 93(1), 201-213. https://doi.org/10.1016/j.polymdegradstab.2007.10.005Lee, D., Song, S.H., Hwang, J., Jin, S.H., Park, K.H., Kim, B.H., Hong, S.H., Jeon, S. (2013). Enhanced mechanical properties of epoxy nanocomposites by mixing noncovalently functionalized boron nitride nanoflakes. Small, 9(15), 2602-2610. https://doi.org/10.1002/smll.201203214Liu, W.D., Zhu, B.K., Zhang, J., Xu, Y.Y. (2007). Preparation and dielectric properties of polyimide/silica nanocomposite films prepared from sol-gel and blending process. Polymers for Advanced Technologies, 18(7), 522-528. https://doi.org/10.1002/pat.910Mat Yazik, M.H., Sultan, M.T.H., Norkhairunnisa Mazlan, Abu Talib, A.R., Naveen, J., Shah, A.U.M., Safri, S.N.A. (2020). Effect of hybrid multi-walled carbon nanotube and montmorillonite nanoclay content on mechanical properties of shape memory epoxy nanocomposite, Journal of Material research and Technology, 9(3), 6085-6100. https://doi.org/10.1016/j.jmrt.2020.04.012Mahesh, Hosur, Tanjheel, H. Mahdi, Mohammad E. Islam, Jeelani, S. (2017). Mechanical and viscoelastic properties of epoxy nanocomposites reinforced with carbon nanotubes, nanoclay, and binary nanoparticles, Journal of Reinforced Plastics and Composites, 36(9), 667-684. https://doi.org/10.1177/0731684417691365Mahesh, Hosur, Tanjheel, Mahdi, Jeelani, S. (2018). Studies on the performance of multi-phased carbon/epoxy composites with nanoclay and multi-walled carbon nanotubes. Multiscale and Multidiscip. Model. Exp. and Des., 1, 255-268. https://doi.org/10.1007/s41939-018-0017-9Rozenberg, B.A., Tenne, R. (2008). Polymer-assisted fabrication of nanoparticles and nanocomposites. Progress in Polymer Science, 33(1), 40-112. https://doi.org/10.1016/j.progpolymsci.2007.07.004Sun, D., Chu, C.C., Sue, H.J. (2010). Simple approach for preparation of epoxy hybrid nanocomposites based on carbon nanotubes and a model clay. Chemistry of Materials, 22(12), 3773-3778. https://doi.org/10.1021/cm1009306Zhou Y. X., Wu P. X., Cheng Z-Y., Ingram J., Jeelani S. (2011). Improvement in electrical, thermal and mechanical properties of epoxy by filling carbon nanotube. Express Polymer Letters, 2(1), 40-48. https://doi.org/10.3144/expresspolymlett.2008.