Group Coordinator: Carlos Alberto Nieto de Castro
The development of new materials and fluids for environment, energy and manufacturing applications (chemical processes)
requires a new approach, guided by European/international regulations and society objectives, using a sustainable chemistry
approach. Research in our group involves the behaviour and structure of complex systems (nano based), by measuring the
thermophysical properties, employing molecular models, developing molecular simulations and designing instruments and
products to be used by industry, with the goal of exploring the links between the structure and interactions of different systems at a
molecular level and the corresponding macroscopic behaviour, contributing to respond to industrial needs in the chemical and
associated industries in areas of technological importance and societal needs. Studied applications, range from high-tech
industries (high temperature molten systems, nanotechnology, polymer foams), and fluid driven technologies (new refrigerants,
new engineering fluids, biomass conversion), to "in situ" thermophysical properties sensing in chemical processes, and new green
industries (ionic liquids, IoNanofluids, IoBiofluids for renewable solar thermal energy).
The properties explored are thermodynamic (densimetry and compressibility, heat capacity, thermal stability, phase equilibria,
enthalpy and chemical activity), transport (thermal and electrical conductivity, viscosity and mass diffusion) and electrical/optical
(refractive index, electrical permittivity). The processes explored involve heat exchanger testing and development, high
temperature thermal conductivity, electrical permittivity and heat capacity metal thin-film sensing, boiling and condensation with
nanofluids, mass transfer in solutions and materials, new catalysts, new polymer products, CO2 capture and Non-Newtonian
These novel fluids have emerged as a possible alternative to current engineering fluids for heat transfer applications.
Thermophysical properties play a crucial role in the chemical plant design of green processes. Existing data is very scarce and
inaccurate. New data on the thermal conductivity, viscosity and density of ionic liquids and IoNanofluids with nanocarbons are also
extremely important to understand the effect of adding nanomaterials to an ionic liquid matrix and its modification of the heat
transfer mechanism, namely the role played by the interface ionic liquid (cation and anion) - nanoparticle, whatever molecular
shape they have. Current theories used to calculate the thermal conductivity enhancement are insufficient to predict its value.
Therefore, the use of molecular dynamics simulations to study the effect of suspended nanocarbons on the thermal conductivity of
ionic liquids can elucidate these mechanisms. Calculations were performed using non-equilibrium molecular dynamics. Work
performed in experimental and molecular simulation contributed for the first time to understand the mechanism of transport in
IoNanofluids, and the extension in space of the molecular interactions.
SECOND-ORDER PHASE TRANSITIONS IN MIXTURES
Second order phase transitions corresponding to discontinuities in the plots of Kirkwood-Buff integrals as a function of
composition were observed in aqueous mixtures of the amphiphilic molecule, 1-propoxypropan-2-ol, revealing the formation of
different types of aggregates and generating microheterogeneities over a limited range of compositions. Electrospray mass
spectra, surface tension measurements and solvatochromic parameters confirmed the onsets of different aggregation patterns
over the entire composition range, and allowed us to scrutinize the prevailing types of aggregate species. This is seemingly the
first time that such discontinuities are clearly assumed as second order phase transitions in a system macroscopically
MELANIN AS A MATERIAL FOR SOLAR ENERGY CONVERSION
An invention providing renewable and sustainable materials for solar thermal energy conversion has been patented (EP 3 228 192
A2) with BASF, resulting from a PhD thesis. Methods for isolating melanin or melanin particles from the ink sac of Cephalopoda as
well as parameters for characterizing melanin or melanin particles, particularly their physico-chemical properties have been
determined. Further, a solar thermal energy selective absorber material, a solar lacquer or a solar paint and a solar thermal
system comprising melanin or melanin particles have been used. In addition, melanin or melanin particles are used as pigment,
e.g., for solar lacquers or paints, or as selective absorber for direct absorption solar collectors or for use in a heat transfer fluid
and/or within solar thermal systems. Contacts with third parties for licensing and further exploitation are under way.
1) Nanofluids: Synthesis, Properties and Applicatios, S. M. Sohel Murshed, C. A. Nieto de Castro, Eds., NOVA Science Publishers, Inc., New York, (2014), ISBN (978-1-63321-677-8).
2) Carlos A. Nieto de Castro, Elisa Langa, Ana L. Morais, Manuel L. Matos Lopes, Maria J. V. Lourenço, Fernando J. V. Santos, M. Soledade C. C. S. Santos, José N. Canongia Lopes, Helena I.M. Veiga, Mafalda Macatrão, José M. S. S. Esperança, Luís P. N. Rebelo, Carolina S. Marques, Carlos A. M. Afonso, “Studies on the density, heat capacity, surface tension and infinite dilution diffusion with the ionic liquids [C4mim][NTf2], [C4mim][dca], [C2mim][EtOSO3] and [aliquat][dca]”, Fluid Phase Eq., 294, 157-179 (2010). DOI: http://dx.doi.org/10.1016/j.fluid.2010.03.010. NC=40; IF (5 year, 2.244).
3) C. A. Nieto de Castro, M. J. V. Lourenço, A. P. C. Ribeiro, E. Langa, S. I. C. Vieira, P. Goodrich, C. Hardacre, “Thermal Properties of Ionic Liquids and IoNanofluids of Imidazolium and Pyrrolidinium Liquids”, J. Chem. Eng. Data, 55 (2), 653-661 (2010). DOI: http://dx.doi.org/10.1021/je900648p. One of 10 Most Read Papers in 2011. NC=42; IF (2013, 2.045).
4) J. M. P. França, C. A. Nieto de Castro, V. M. B. Nunes, M. L. S. Matos Lopes, “The Influence of Thermophysical Properties of Ionic Liquids in Chemical Process Design”, J. Chem. Eng. Data, 54, 2569–2575 (2009), DOI: http://dx.doi.org/10.1021/je900107t . NC=30; IF (2013, 2.045).
5) S. M. Sohel Murshed, C. A. Nieto de Castro, M. J. V. Lourenço, M. L. M. Lopes and F. J. V. Santos, “A review of boiling and convective heat transfer with nanofluids”, Renewable and Sustainable Energy Reviews, 15, 2342–2354 (2011). DOI: http://dx.doi.org/10.1016/j.rser.2011.02.016 . NC=37; IF (5 year, 6.577).
6) P. Goodrich, C. Hardacre, C.Paun, A. Ribeiro, S. Kennedy, M.J.V. Lourenço, H. Maynar, C. A. Nieto de Castro, M.Besnea, V.I. Pârvulescuc, “Confinement effects for Asymmetric carbon-carbon bond forming reactions catalysed by Metal (II) complexes immobilized using Supported Ionic Liquid thin films”, Adv. Synth. Catal., 353, 995 – 1004 ( 2011).DOI: http://dx.doi.org/10.1002/adsc.201000953. NC=9; IF (2013, 5.542) Ranking 2013, 2/71 (Chemistry Applied).
7) J. C. R. Reis, T. P. Iglesias, G. Douhéret, M. I. Davis, “The permittivity of thermodynamically ideal liquid mixtures and the excess relative permittivity of binary dielectrics”, Phys. Chem. Chem. Phys., 11, 3977-3986, (2009). DOI: http://dx.doi.org/10.1039/B820613A . NC=22; IF (2013, 4.198).
8) J. C. R. Reis, I. M. S. Lampreia, A. F. S. Santos, M.-L. C. J. Moita, G. Douhéret, Refractive index of Liquid Mixtures: Theory and Experiment, ChemPhysChem., 11, 3722 – 3733, (2010). DOI: http://dx.doi.org/10.1002/cphc.201000566. NC=22; IF (2013, 3.360).
9) D. A. R. S. Latino, R. P. S. Fartaria, F. F. M. Freitas, J. Aires-de-Sousa, F. M. S. S. Fernandes, “Mapping Potential Energy Surfaces by Neural Networks. The Ethanol/Au(111) Interface”, J. Electroanalytical Chem., 624 (2008) 109. DOI: http://dx.doi.org/10.1016/j.jelechem.2008.07.032. NC=12; IF (5 year, 2.909).
10) P. Rodrigues, F. M. S. S. Fernandes, “Induction of Crystal Growth in Alkali-Halides Aggregates by means of Internal Seeding”, Eur. Phys. J. D, (2012) 66: 170. DOI: http://dx.doi.org/10.1140/epjd/e2012-30047-y. NC=8; IF (2013, 1.398).