Visiting Fellow
Dr Amir Razmjou Chaharmahali
Engineering
School of Chemical Engineering
“Spending more than a decade on teaching, research and development, Dr Razmjou has accrued multidisciplinary skills to develop innovative technologies for biomedical and environmental applications. He received his PhD in Chemical Engineering from UNSW, 2012. His surface architecturing skills using functional nanostructured materials alongside biofunctionalization have helped him to develop innovative membranes for desalination and water treatment, and nanobiosensors. Inspiring form nature, ion-selective nanochannels, and nanopores are strategically being designed to utilize for selectively controlling transportation phenomena in atomic scale. Dr Razmjou’s current research focuses on designing ion-selective nanostructured membranes for Lithium (Li) ion separations and resource recovery, developing advanced Biomicrofluidics systems using microfabrication technologies, and biocatalytic conversion of CO2 using membranes. Dr Razmjou, the editorial board member of Desalination, has published more than 100 peer-reviewed papers (Dec 2020) in related top-tier journals and supervised more than 20 postgraduate students. “
His current research focuses on designing ion selective membranes for Lithium (Li) ion separations and resource recovery, developing advanced Biomicrofluidics systems using microfabrication technologies and biocatalytic conversion of CO2.
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Advanced Lithium (Li) ion selective membranes:
Dr Razmjou current research activities focus on designing Lithium ion selective membranes to be used in Li recovery, and Li selective electrodes and sensing.
Dr Razmjou’s experience and skills in developing “nanostructured materials” and “membranes” have been used for developing Li ion selective nanostructured membranes.
Razmjou’s group produced more than 55 publications about nanostructured materials and 40 papers directly related to membrane technology (Dec 2020). Dr Razmjou’s team was the first to discover that Li ions transport in a Zig-Zag fashion within the sub-nanometre channels due to the spontaneous breaking of charge symmetry[1]. The discovery that laid a foundation for his future work and was published in 2019 in Water Research entitled “Lithium ion-selective membrane with 2D subnanometer channels”, and is not only among highly cited papers but has also been chosen as a Hot Paper by the Web of Science.
Dr Razmjou is also pioneered in introducing a framework for the design of Li ion selective membranes[2]. The framework was published in Nature Communication 2019 entitled “Design principles of ion-selective nanostructured membranes for the extraction of lithium ions” and has been chosen among the “Top 50 Chemistry and Materials Sciences Articles” in Nature.
Using Molecular Dynamics (MD) simulation, Dr Razmjou recently, studied the effect of chemistry and geometry of GO nanochannels on the Li ion selectivity and recovery[3]. In his paper published in Desalination, He argued that the best way to boost Li ion selectivity is through creating asymmetry in morphology or chemistry of nanochannels.
One of the main obstacle hindering the commercial implementation of MOF and 2D based Li ion selective membranes is difficulty in scaling them up. In his recently published work in Applied Materials Today (2020), he proved the possibility of creating a rapid and facile Li selective coherent MOF thin film on a “flexible polymeric” membrane[4], this is a significant step froward in commercial implementation of MOF materials. Another main issue in creating Li ion selective membranes is microdefects. In his communication in Advanced Materials Interfaces, Dr Razmjou explained that the microdefects can bypass the high entry energy barrier of nanochannels and allow non-selective ionic transport through cracks or pinholes[5].
Dr Razmjou also interested in the incorporation of gust molecules as ion trappers into 2D based membranes. For instances in his recent work published in Advanced Materials technologies, that tannic acid (TA) inside graphene oxide (GO) nanochannel acts as natural ion trapper, which possesses lithiophilic elements[6].
Another current challenge in producing Li from brine is related to the fact that the extraction process of lithium from brine normally starts with a solar evaporation pond to increase the lithium concentration, which takes more than a year and is weather-dependent and has environmental concerns. Dr Razmjou actively is developing advanced processes for concentrating brine for lithium recovery. In his recent work published in Desalination, he evaluated the enrichment of lithium from salt lake brine using graphene oxide (GO) composite pervaporation membrane with the crystallizer unit[7].
References
1. Razmjou, A., et al., Lithium ion-selective membrane with 2D subnanometer channels. Water Research, 2019. 159: p. 313-323.
2. Razmjou, A., et al., Design principles of ion selective nanostructured membranes for the extraction of lithium ions. Nature Communications, 2019. 10(1).
3. Razmjou, A., et al., Effect of chemistry and geometry of GO nanochannels on the Li ion selectivity and recovery. Desalination, 2020. 496.
4. Mohammad, M., et al., Metal-Phenolic network and metal-organic framework composite membrane for lithium ion extraction. Applied Materials Today, 2020. 21: p. 100884.
5. Razmjou, A., The Role of Defects in Li+ Selective Nanostructured Membranes: Comment on “Tunable Nanoscale Interlayer of Graphene with Symmetrical Polyelectrolyte Multilayer Architecture for Lithium Extraction”. Advanced Materials Interfaces, 2019. 6(2): p. 1801427.
6. Ahmadi, H., et al., Incorporation of Natural Lithium-Ion Trappers into Graphene Oxide Nanosheets. Advanced Materials Technologies, 2020.
7. Cha-umpong, W., et al., Concentrating brine for lithium recovery using GO composite pervaporation membranes. Desalination, 2020: p. 114894.