Visit main University website

Neto Research Group

Neto Research Group

Neto Research Group

Our research

Nanotextured surfaces with anti-fouling and drag-reducing properties

Marine fouling and drag cause damage to infrastructure and high emissions in shipping. The Neto group investigates new ways of understanding, controlling, and reducing marine fouling and drag. In 2016 we explained how lubricant-infused surfaces reduce marine fouling of surfaces immersed in the ocean, and in 2022 we explained how interfacial air nanobubbles nucleating on lubricant-infused surfaces reduce drag up to 15%. We obtained preliminary evidence that gas bubbles on lubricant-infused surfaces are more stable to applied to applied pressure that on superhydrophobic surfaces, and confirmed this in 2025 by confocal microscopy study in static conditions.  In 2021 we developed a thorough understanding of how lubricant is lost from infused surfaces crossing air-water interfaces, and a year later we conducted CFD simulations demonstrating that even a small degree of lubricant depletion can reduce the drag reduction induced by these surfaces, confirming that it is indeed surface nanobubbles that convey most of the drag reduction. This research was enabled by maximising the precision and reliability of microfluidic experiments.

References

  1. L. James, C. Vega-Sánchez, P. Mehta, X. Zhang, C. Neto*; “Experimental Study of Gas Microbubbles on Oil-Infused Wrinkled Surfaces”, Adv. Mater. Interfaces, accepted 15/04/2025
  2. A. Naga, L. Scarratt, C. Neto, P. Papadopoulos, D. Vollmer; “Friction and Failure on Superhydrophobic and Slippery Surfaces”, ACS Nano, 2025, accepted.
  3. C. Vega-Sánchez, C. Neto*; “Slightly Depleted Lubricant-infused Surfaces Are No Longer Slippery”, Langmuir (2022) https://doi.org/10.1021/acs.langmuir.2c01412 Open access: https://hdl.handle.net/2123/31693
  4. Vega-Sánchez and C. Neto, C. Fluid Slip and Drag Reduction on Liquid-Infused Surfaces under High Static Pressure. Langmuir 40, 4460-4467, doi:10.1021/acs.langmuir.3c03792 (2024). Open access: https://hdl.handle.net/2123/33731
  5. S. Peppou-Chapman, C. Vega-Sanchez, C. Neto*; “Detection of Nanobubbles on Lubricant-Infused Surfaces Using AFM Meniscus Force Measurements”, Langmuir 10.1021/acs.langmuir.2c01411 (2022) Open access: https://hdl.handle.net/2123/31696
  6. S. Peppou-Chapman, J. K. Hong, A. Waterhouse, C. Neto*; “Life and death of liquid-infused surfaces: a review on the choice, analysis and fate of the infused liquid layer”, Chem. Soc. Rev. 49, 3688-3715 (2020) Open access: https://hdl.handle.net/2123/27554
  7. Vega-Sánchez, C; Peppou-Chapman, S; Zhu, L; Neto, C*; “Nanobubbles explain the large slip observed on lubricant-infused surfaces” Nature Comm.. 13, 351 (2022). DOI:10.1038/s41467-022-28016-1 Journal open access
  8. C.S. Ware, T. Smith-Palmer, S. Peppou-Chapman, L.R.J. Scarratt, E.M. Humphries, D. Balzer, C. Neto*; “Marine Antifouling Behavior of Lubricant-Infused Nanowrinkled Polymeric Surfaces” ACS Appl. Mater. Interfaces 2018, 10, 4173−4182. Open access: https://hdl.handle.net/2123/27856
  9. Lee, T.; Charrault, E.; Neto, C. Interfacial slip on rough, patterned and soft surfaces: A review of experiments and simulations. Adv. Colloid Interface Sci. 2014, 210, 21-38. Open access: https://hdl.handle.net/2123/21431

Liquid-like PDMS nanothin layers with ultra-low droplet friction

In our 2023 Angewandte Chemie paper we observed oil molecules retaining their ‘liquid-like’ properties when they were chemically attached as a nano-thin layer to solid surfaces, opening new possibilities for designing sustainable materials with non-stick characteristics. The ‘liquid-like’ coatings, known as slippery covalently-attached liquid surfaces (SCALS), are amongst the most slippery to droplets ever prepared, without relying on problematic perfluorinated polymers (PFAS), ‘forever chemicals’ that are usually used for their low adhesion properties. In 2025 we collaborated with colleagues in two different labs (Prof McHale at Uni Edinburgh and Prof Golovin at Uni Toronto) to explain the grafting reactions leading to these liquid-like surfaces reliably and reproducibly. In combined experiments and MD simulations we have shown that the most slippery SCALS are dense brushes that are ultra-smooth, and in which the chain length is not long enough to envelop liquid droplets placed on the surface. This work complements earlier work on the properties of anti-thrombotic slippery layers.

References

  1. I.J. Gresham, H. Barrio-Zhang, J..H Cho, B. Khatir, G.G. Wells, K. Golovin, G. McHale, C. Neto*; “Comparative study on protocols to prepare slippery liquid-like PDMS coatings – pitfalls and time-savers” (2025) ChemRxiv. 2025; doi:10.26434/chemrxiv-2025-hnwz1 
  2. F. Rasera, I. J. Gresham, A. Tinti, C. Neto*, A. Giacomello; “Molecular origin of slippery behavior in tethered liquid layers” ACS Nano (2025) https://doi.org/10.1021/acsnano.4c15843
  3. J.K. Hong, I. J. Gresham, D. Daniel, A. Waterhouse, C. Neto*; “Visualizing Nanoscale Lubricant Layer Under Blood Flow” ACS Appl. Mater. Interfaces 15, 56433–56441 (2023) https://doi.org/10.1021/acsami.3c11898 Open access: https://hdl.handle.net/2123/33405
  4. I. J. Gresham, S. G. Lilley, A. R.J. Nelson, K. Koynov, C.Neto*; “Nanostructure Explains the Behavior of Slippery Covalently Attached Liquid Surfaces” Angew. Chemie e202308008 (2023) https://doi.org/10.1002/anie.202308008 Journal open access
  5. G. McHale, R. Ledesma-Aguilara, C. Neto; “Cassie’s Law Reformulated: Composite Surfaces From Superspreading to Superhydrophobic” Langmuir 39, 11028-11035 (2023) doi:10.1021/acs.langmuir.3c01313 Journal open access
  6. I.J. Gresham, C. Neto*; “Advances and challenges in slippery covalently-attached liquid surfaces” Adv. Colloid Interface Sci. 315, 102906, doi:10.1016/j.cis.2023.102906 (2023). Open access: https://hdl.handle.net/2123/33191
  7. J.K. Hong, A.M. Ruhoff, K. Mathur, C. Neto, A. Waterhouse; “Mechanisms for Reduced Fibrin Clot Formation on Liquid-Infused Surfaces” Adv. Healthcare . Mater. 11, 2201360(2022) with front cover Journal open access
  8. J.K. Hong, K. Mathur, A. M. Ruhoff, B. Akhavan, A. Waterhouse, C. Neto*; “Design Optimization of Perfluorinated Liquid-Infused Surfaces for Blood-Contacting Applications”, Adv. Mater. Interf. (2022) accepted 20/12/2021 (IF = 6.14) First published: 29 January 2022 https://doi.org/10.1002/admi.202102214 Open access: https://hdl.handle.net/2123/31696

Gas enrichment at liquid-liquid interfaces

Water and organic solvents contain significant concentration of dissolved air, around 1 mM, which is often ignored when modelling interfaces. A Discovery project of the Australian Research Council is supporting work to investigate the accumulation of dissolved gas at liquid-liquid interfaces, and its potential effect of interfacial flow. Our collaborator Prof Giacomello at the University of Rome has shown that the gas accumulation could lead to significant slip.

Advanced capture of water from the atmosphere

Maintaining a stable supply of drinking water in Australia is a continual challenge. In 2006 the Australian mainland was gripped by “the worst drought in 1000 years”, with the once-ferocious Murray River receiving only 5% of its average inflow. Existing technical solutions to water shortages are energy intensive, result in water wastage through evaporation, or are potentially environmentally damaging. The Neto group explores harvesting water directly from the atmosphere as a viable alternative, which could provide an energy-effective and localised method of water capture, especially useful in remote communities where the local humidity is high. We have focused on the surface properties, such as wettability and liquid-like behaviour, that could increase the efficiency of the water collection. Part of this research resulted in the incorporation of start-up company Dewpoint Innovations.

References

  1. C. Neto. & M. Chiu; “A composite material for reducing temperature gain and/or increasing atmospheric condensation on a surface of a substrate”. PCT/AU2024/050318, PCT Publication No. WO2024/207065, published 10/10/2024.
  2. A. Katselas, I. J. Gresham, A. R. J. Nelson, C. Neto “Exploring the water capture efficiency of covalently attached liquid-like surfaces” J. Chem. Phys. (2023) https://doi.org/10.1063/5.0146847 Journal open access
  3. A. Katselas, R. Parin, C. Neto*; “Quantification of Nucleation Site Density as a Function of Surface Wettability on Smooth Surfaces” Adv. Mater. Interfaces 9, 2200246 (2022) Journal open access
  4. C. Neto, C. M. de Sterke, M. Chiu, “A composite coating for increasing atmospheric condensation on a surface of a substrate” PCT/AU2021/050221 https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2021179052, 2021
  5. M. Chiu, J. A. Wood, A. Widmer-Cooper, C. Neto*; “Aligned Droplet Patterns by Dewetting of Polymer Bilayers” Macromolecules, 51 (15), pp 5485–5493 (2018).
  6. N. Gao, M. Chiu, C. Neto*; “Receding Contact Line Motion on Nano- and Micro-patterned Polymer Surfaces” Langmuir 33, 12602−12608 (2017).

Advanced additives for superior paint coatings

The Neto group has worked for over 18 years in collaboration with leading paint company Dulux Australia to advance paint through the addition of nanostructured additives that improve the stain resistance, robustness, and sustainability of paint. In collaboration with leading emulsion polymerisation experts in the Key Centre for Polymers and Colloids, the Neto group reveals the mechanisms underpinning desirable functions in paint. In this collaborative work with Dulux we showed how Janus nanoparticles synthesised in large quantities can be used to encapsulate solid pigment particles and oil droplets, without the need for high temperature polymerisation.

References

  1. G. Turpin, D. Nguyen, K. Sypkes, C. Vega-Sanchez, T. Davey, B.S. Hawkett, C. Neto*; “Encapsulation of oil droplets using film-forming Janus nanoparticles” (2025) Langmuir https://doi.org/10.1021/acs.langmuir.4c03843
  2. G. Turpin, D. Nguyen, P. Subramanian, T. Davey, S. F. Cheong, Greg Warr, C. Neto*, Brian Hawkett “Tensile benefits of nanofibers in commercial paint” Polym. Chem. (2024) 10.1039/d3py01335a. Open access https://hdl.handle.net/2123/33733
  3. D. Nguyen, L. Zhu, V. T. Huynh, A. Azniwati, N. T. H. Pham, M. T. Lam, A. K. Serelis, T. Davey, C. Such, C. Neto, B. S. Hawkett; “Soft-Hard Janus Nanoparticles for Polymer Encapsulation of Solid Particulate”, Polym. Chem. 11, 5610-5618 (2020) Open access: https://hdl.handle.net/2123/27842
  4. H.T.T. Duong, D. Nguyen, C. Neto*, B. S. Hawkett; Chapter 2 “Synthesis and applications of polymeric Janus nanoparticles”, in “Soft, Hard, and Hybrid Janus Structures: Synthesis, Self-Assembly, and Applications”, (pp. 31-68), edited by Zhiqun Lin and Bo Li, World Scientific (2018).
  5. L. Zhu, D. Nguyen, T. Davey, M. Baker, C. Such, B. S. Hawkett, C. Neto*; “Mechanical properties of Ropaque hollow nanoparticles” Polymer 131, 10-16, (2017).

Pages: 1 2