This project will develop new chemical/technological solutions for controlling evaporation from water storages and irrigation channels.
Australia is one of the driest continents on earth and it is not yet clear how climate change will impact on rainfall patterns and therefore water supplies. Large areas of the country have suffered drought and most of our major population centres continue to experience significant water restrictions. Protecting, maintaining and minimising losses from our water supplies is therefore a priority. This project will develop new chemical/technological solutions for evaporation control from water storages and irrigation channels. Annual evaporative losses of water from storages can exceed 40% of water stored. The use of ultra-thin layers (monolayers) formed from environmentally benign chemicals/polymers has the potential to reduce evaporation losses and at the same time be cost effective and applicable to all storage sizes.
In collaboration with the experimental team at the University of Melbourne, this research uses theoretical modelling techniques to develop more stable and effective molecular monolayers to suppress evaporation from open water storages. The design of new monolayers will incorporate the following important and novel features:
- Evaporation suppression: Optimum packing density will maximise evaporation resistance while still enabling air diffusion to the water layer, and when combined with multi-zoned functionality (alternating hydrophilic and hydrophobic zones) in the interfacial region of the monolayer, (Fig. 1), will alter the surface structure of water and improve evaporation resistance by creating an energetically unfavourable path for water migration.
- Wind stability: Development of more versatile hydrophilic anchors will ensure deeper penetration of the water layer and stronger bonding to water to increase wind resistance.
- Temperature stability: Development of novel polymer “comb“ materials for incorporation in the monolayer will ensure suitable hydrophobic v hydrophilic balance to prevent dissolution at warmer temperatures and improve temperature stability.
- Environmentally safe: These materials will be designed to have no impact on the environment or water quality over their life-cycle.
Using classical potentials we calculate monolayer structure and properties as a function of surface density and temperature. With this knowledge we are then able to propose modifications that will lead to improved anchoring of the monoloayer to the water surface and improved evaporation resistance. Theoretical findings are tested against experimental benchmarks.
Simulations are performed using fully atomistic theoretical models of surfaces. The energy of the interactions is calculated using the OPLS and COMPASS forcefields.
- Professor Irene Yarovsky – Team leader
- Dr George Yiapanis – Research Fellow
- Mr Michael Plazzer – PhD student
- Mr Patrick Charchar – Undergraduate student
- Dr David Henry (2009-2010)
University of Melbourne
University of Calgary, Canada
- Dynamic Performance of Duolayers at the Air/Water Interface - Part A: Experimental Analysis, A. Leung, E. Prime, D. Tran, Q. Fu, A. Christofferson, G. Yiapanis, I. Yarovsky, G.G. Qiao, and D. H. Solomon, J.Phys Chem B, 118 (2014) 10919−10926
- Dynamic Performance of Duolayers at the Air/Water Interface - Part B: Mechanistic Insights from All-atom Simulations, A. Christofferson, G. Yiapanis, A. Leung, E. Prime, D. Tran, G. G. Qiao, D. H.Solomon, and I. Yarovsky, J. Phys. Chem. B, 118 (2014) 10927−10933
- Molecular mechanisms of stabilisation of thin organic films on water, G. Yiapanis, A. Christofferson, M. Plazzer, M. Weir, E. Prime, G. Qiao, D. Solomon, I. Yarovsky, Langmuir, 29 (2013) 14451−14459
- Molecular interactions behind the synergistic effect in mixed monolayers of 1-octadecanol and ethylene glycol monooctadecyl ether, D. N. H. Tran, E. L. Prime, M. Plazzer, A. H. M. Leung, G. Yiapanis, A. J. Christofferson, I. Yarovsky, G. Qiao, and D. H. Solomon, J. Phys. Chem. B 117 (2013) 3603-3612
- Prime, Emma L., Diana NH Tran, Michael Plazzer, Devi Sunartio, Andy HM Leung, George Yiapanis, Svetlana Baoukina, Irene Yarovsky, Greg G. Qiao, and David H. Solomon. "Rational design of monolayers for improved water evaporation mitigation." Colloids and Surfaces A: Physicochemical and Engineering Aspects (2012).
- Prime, Emma L., David J. Henry, Irene Yarovsky, Greg G. Qiao, and David H. Solomon. "Comb polymers: Are they the answer to monolayer stability?" Colloids and Surfaces A: Physicochemical and Engineering Aspects 384, no. 1 (2011): 482 489.
- Plazzer, Michael B., David J. Henry, George Yiapanis, and Irene Yarovsky. "Comparative study of commonly used molecular dynamics force fields for modeling organic monolayers on water." The Journal of Physical Chemistry B 115, no. 14 (2011): 3964-3971.
- Henry, David J., Visham I. Dewan, Emma L. Prime, Greg G. Qiao, David H. Solomon, and Irene Yarovsky. "Monolayer structure and evaporation resistance: a molecular dynamics study of octadecanol on water." The Journal of Physical Chemistry B 114, no. 11 (2010): 3869-3878.
Conference / Poster presentations
- Plazzer, M.B. ;Yiapanis, G.; Yarovsky, I. “Study of Self-Assembling Monolayers.“ 18th International Symposium on Surfactants in Solution, Melbourne, 2010.
- Plazzer, M.B. ;Yiapanis, G.; Yarovsky, I. “Stability of Organic Monolayers on Water: A Molecular Dynamics Study.“ Molecular Modelling Conference, Melbourne, 2010.