Leonardo Chiappisi

Surfactants are among the simplest building blocks in the colloidal playground. Nevertheless, they exhibit an astonishingly rich behavior. In my research activity, I probe the behavior of very different class of surfactant, explore their response to changes in their chemical or physical environment, with the aim of a better understanding of their properties and to design simpler, greener, surfactant-based systems.

Publications on this topic:

• 14.  dos Santos Silva Araújo, L.; Lazzara, G.; Chiappisi, L. Thermoresponsive Behavior of Cyclodextrin Inclusion Complexes with Weakly Anionic Alkyl Ethoxy Carboxylates. Soft Matter2023. doi:10.1039/D2SM01621D.
• 13. dos Santos Silva Araújo, L.; Watson, L.; Traore, D. A. K.; Lazzara, G.; Chiappisi, L. Hierarchical Assembly of pH-Responsive Surfactant–Cyclodextrin Complexes. Soft Matter2022, 8 (35), 6529–6537. doi:10.1039/D2SM00807F.
• 12. Esposito, R.; Ingenito, L.; Cavasso, D.; Siciliano, A.; Laura Alfieri, M.; Chiappisi, L.; Fragneto, G.; Francesca Ottaviani, M.; Guida, M.; Paduano, L.; D’Errico, G. Rhamnolipid–SLES Aqueous Mixtures: From the Molecular Self-Aggregation to the Functional and Ecotoxicological Properties. J. Mol. Liq.2022, 120547. doi:10.1016/j.molliq.2022.120547.
• 11. Chiappisi, L.; Hoffmann, I.; Gradzielski, M. Membrane Stiffening in Chitosan Mediated Multilamellar Vesicles of Alkyl Ether Carboxylates. J. Colloid Interface Sci.2022, 627, 160-167. doi:10.1016/j.jcis.2022.07.006.
• 10. dos Santos Silva Araújo, L.; Lazzara, G.; Chiappisi, L. Cyclodextrin/Surfactant Inclusion Complexes: An Integrated View of Their Thermodynamic and Structural Properties. Adv. Colloid Interface Sci.2021, 289, 102375. doi:10.1016/j.cis.2021.102375
• 9. Crivello, C.; Lazzara, G.; Chiappisi, L. On the Effect of the Nature of Counterions on the Self-Assembly of Polyoxyethylene Alkyl Ether Carboxylic Acids. Soft Matter 2020. doi:10.1039/D0SM00986E
• 8. Hayward, D. W.; Chiappisi, L.; Teo, J. H.; Prévost, S.; Schweins, R.; Gradzielski, M. Neutralisation Rate Controls the Self-Assembly of PH-Sensitive Surfactants. Soft Matter 2019, 15 (42), 8611–8620. doi:10.1039/c9sm00950g
• 7. L. Chiappisi, U. Keiderling, C.E. Gutierrez-Ulloa, R. Gómez, M. Valiente, M. Gradzielski Aggregation Behavior of Surfactants with Cationic and Anionic Dendronic Head Groups. J. Colloid Interface Sci. 2018. doi:10.1016/j.jcis.2018.09.005
• 6. Schwarze, M.; Schaefer, L.; Chiappisi, L.; Gradzielski, M. Micellar Enhanced Ultrafiltration (MEUF) of Methylene Blue with Carboxylate Surfactants. Sep. Purif. Technol. 2018doi:10.1016/j.seppur.2018.01.043
• 5. Chiappisi, L. Polyoxyethylene Alkyl Ether Carboxylic Acids: An Overview of a Neglected Class of Surfactants with Multiresponsive Properties. Adv. Colloid Interface Sci. 2017doi:10.1016/j.cis.2017.10.001
• 4. Chiappisi, L.; David Leach, S.; Gradzielski, M. Precipitating Polyelectrolyte–surfactant Systems by Admixing a Nonionic Surfactant – a Case of Cononsurfactancy. Soft Matter 2017, 13 (29), 4988–4996. doi:10.1039/C7SM00747G
• 3. Chiappisi, L.; Yalcinkaya, H.; Gopalakrishnan, V. K.; Gradzielski, M.; Zemb, T. Catanionic surfactant systems - thermodynamic and structural conditions revisited. Colloid and Polymer Science 2015, 293, 1–13. doi:10.​1007/​s00396-015-3739-9
• 2. Schwarze, M.; Groß, M.; Moritz, M.; Buchner, G.; Kapitzki, L.; Chiappisi, L.; Gradzielski, M. Micellar Enhanced Ultrafiltration (MEUF) of Metal Cations with Oleylethoxycarboxylate. Journal of Membrane Science 2015, 478, 140–147. doi:10.1016/j.memsci.2015.01.010
• 1. Schwarze, M.; Chiappisi, L.; Prévost, S.; Gradzielski, M. Oleylethoxycarboxylate - An Efficient Surfactant for Copper Extraction and Surfactant Recycling via Micellar Enhanced Ultrafiltration. Journal of Colloid and Interface Science 2014, 421, 184-190 doi:10.1016/j.jcis.2014.01.037

Chitosan is the deacetylated form of chitin, the second most abundant biopolymer after cellulose. This unique polysaccharide attracts wide interests due to its peculiar combination of characteristics. The presence of the amino groups along its backbone, imparts to the polymer a positive charge in acidic aqueous environment. In my research activity, the complex, self-organization behavior in mixtures of chitosan and oppositely charged surfactants is studied and exploited for the design of novel functional materials.

Publications on this topic:

• 12. Garreau, C.; Chiappisi, L.; Micciulla, S.; Blanc, N.; Morfin, I.; Desorme, A.; Mignot, T.; Trombotto, S.; Delair, T.; Sudre, G. Grafted Chitosan Thin Films of Various Degrees of Acetylation as a Reusable Platform for the Investigation of Biological Interactions. Int. J. Biol. Macromol.2023, 245, 125565. doi:10.1016/j.ijbiomac.2023.125565.
• 11. Garreau, C.; Chiappisi, L.; Micciulla, S.; Morfin, I.; Trombotto, S.; Delair, T.; Sudre, G. Preparation of Highly Stable and Ultrasmooth Chemically Grafted Thin Films of Chitosan. Soft Matter2023. doi:10.1039/D3SM00003F.
• 10. Chiappisi, L.; Hoffmann, I.; Gradzielski, M. Membrane Stiffening in Chitosan Mediated Multilamellar Vesicles of Alkyl Ether Carboxylates. J. Colloid Interface Sci.2022, 627, 160-167. doi:10.1016/j.jcis.2022.07.006.
• 9. Cavallaro, G.; Micciulla, S.; Chiappisi, L.; Lazzara, G. Chitosan-Based Smart Hybrid Materials: A Physico-Chemical Perspective. J. Mater. Chem. B 2021, 9 (3), 594–611. doi:10.1039/D0TB01865A.
• 8. Micciulla, S.; Hayward, D.W.; Gerelli, Y.; Panzarella, A.; von Klitzing, R.; Gradzielski, M.; Chiappisi, L. One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings. Communications Chemistry, 1, 2019, 61. doi:10.1038/s42004-019-0155-y
• 7. Chiappisi, L.; David Leach, S.; Gradzielski, M. Precipitating Polyelectrolyte–surfactant Systems by Admixing a Nonionic Surfactant – a Case of Cononsurfactancy. Soft Matter 2017, 13 (29), 4988–4996. doi:10.1039/C7SM00747G
• 6. Chiappisi, L.; Gradzielski, M. Chitosan Surfactant Systems for Home and Health Care Products: Limitations and Potentials. Househ. Pers. Care Today 2016, 11, 8–11. Link
• 5. Chiappisi, L.; Gradzielski, M. Co-Assembly in Chitosan–surfactant Mixtures: Thermodynamics, Structures, Interfacial Properties and Applications. Advances in Colloid Interface Science 2015, 220, 92–107. doi:10.1016/j.cis.2015.03.003
• 4. Chiappisi, L.; Simon, M.; Gradzielski, M. Toward Bioderived Intelligent Nanocarriers for Controlled Pollutant Recovery and pH-Sensitive Binding. ACS Applied Materials & Interfaces 2015, 7, 6139–6145, doi:10.1021/am508846r
• 3. Chiappisi, L.; Prevost, S.; Grillo, I.; Gradzielski, M. From Crab Shells to Smart Systems: Chitosan - Alkylethoxy Carboxylates Complexes. Langmuir 2014, 30, 10608–10616. doi:10.1021/la502569p
• 2. Chiappisi, L.; Prevost, S.; Grillo, I.; Gradzielski, M. Chitosan/Alkylethoxy Carboxylates - A Surprising Variety of Structures. Langmuir 2014, 30, 1778-1787 doi: 10.1021/la404718e
• 1. Chiappisi, L.; Hoffmann, I.; Gradzielski, M. Complexes of oppositely charged polyelectrolytes and surfactants – recent developments in the field of biologically derived polyelectrolytes. Soft Matter 2013, 9, 3896 – 3909. doi:10.1039/c3sm27698h 

Exploring the behavior of soft matter upon application of an external pressure is at the same a fascinating and challenging topic. The interest into performing this studies is twofold. In the first place, pressure is an extensive thermodynamic parameter, as it is temperature. By the variation of pressure, we can explore the energetic landscape of a system, and obtain a deeper understanding of the interactions within the components and the driving forces governing its behavior. Sudden pressure variations, i.e, pressure-jumps allow us to probe the mechanism trough which certain processes take place, e.g., the mixing or demixing of polymer solutions. In addition, pressure is a technically highly relevant parameter, and understanding its effect on different colloidal systems will allow us to improve the design of, e.g., synovial fluids, pressure-responsive coatings, actuators, etc.

Publications on this topic:

• 5. Micciulla, S.; Gutfreund, P.; Kanduč, M.; Chiappisi, L. Pressure-Induced Phase Transitions of Nonionic Polymer Brushes. Macromolecules2023. doi:10.1021/acs.macromol.2c01979.
• 4. Niebuur, B.-J.; Chiappisi, L.; Jung, F. A.; Zhang, X.; Schulte, A.; Papadakis, C. M. Nanoscale Disintegration Kinetics of Mesoglobules in Aqueous Poly( N -Isopropylacrylamide) Solutions Revealed by Small-Angle Neutron Scattering and Pressure Jumps. Nanoscale2021, 13 (31), 13421–13426. doi:10.1039/D1NR02859F.
• 3. Niebuur, B.-J.; Ko, C.-H.; Zhang, X.; Claude, K.-L.; Chiappisi, L.; Schulte, A.; Papadakis, C. M. Pressure Dependence of the Cononsolvency Effect in Aqueous Poly( N -Isopropylacrylamide) Solutions: A SANS Study. Macromolecules 2020, 53 (10), 3946–3955. doi:10.1021/acs.macromol.0c00489
• 2. B. Niebuur, L. Chiappisi, F. Jung, X. Zhang, A. Schulte, C. M. Papadakis Kinetics of Mesoglobule Formation and Growth in Aqueous Poly(N-isopropylacrylamide) Solutions: Pressure Jumps at Low and at High Pressure. Macromolecules, 52, 2019, 6416-6427. doi:10.1021/acs.macromol.9b00937
• 1. B.-J. Niebuur, L. Chiappisi, X. Zhang, F. Jung, A. Schulte, C.M. Papadakis Formation and Growth of Mesoglobules in Aqueous Poly( N -isopropylacrylamide) Solutions Revealed with Kinetic Small-Angle Neutron Scattering and Fast Pressure Jumps. ACS Macro Lett. 2018, 1155–1160. doi:10.1021/acsmacrolett.8b00605

Liquid foams are a recent focus of my research in the realm of colloidal science. These intriguing materials consist of gas bubbles dispersed within a liquid matrix, and they find applications across various industries, from cosmetics to food production. Understanding the stabilization, drainage, and coarsening processes in liquid foams is essential for optimizing their properties and performance. My work involves investigating the intricate interplay of forces and interfaces that govern foam behavior. Neutron scattering techniques provide valuable insights into the structural and dynamical properties of foams at the nanoscale.

Publications on this topic:

• 2. Lamolinairie, J.; Dollet, B.; Bridot, J.-L.; Bauduin, P.; Diat, O.; Chiappisi, L. Probing Foams from the Nanometer to the Millimeter Scale by Coupling Small-Angle Neutron Scattering, Imaging, and Electrical Conductivity Measurements. Soft Matter2022. doi:10.1039/D2SM01252A.
• 1. Kühnhammer, M.; Braun, L.; Ludwig, M.; Soltwedel, O.; Chiappisi, L.; von Klitzing, R. A New Model to Describe Small-Angle Neutron Scattering from Foams. J. Appl. Crystallogr.2022, 55 (4). doi:10.1107/S1600576722004691.

Polymers are a fundamental class of materials in the realm of colloidal science, playing a pivotal role in my research as a physico-chemist. These versatile macromolecules, exhibit a wide range of properties that greatly influence the behavior of colloids and soft matter systems. Understanding the interactions and dynamics of polymers within these systems is essential for advancing our knowledge in material science, particularly in the context of designing and engineering novel colloidal materials with tailored properties.

Publications on this topic:

• 8. Garreau, C.; Chiappisi, L.; Micciulla, S.; Blanc, N.; Morfin, I.; Desorme, A.; Mignot, T.; Trombotto, S.; Delair, T.; Sudre, G. Grafted Chitosan Thin Films of Various Degrees of Acetylation as a Reusable Platform for the Investigation of Biological Interactions. Int. J. Biol. Macromol.2023, 245, 125565. doi:10.1016/j.ijbiomac.2023.125565.
• 7. Garreau, C.; Chiappisi, L.; Micciulla, S.; Morfin, I.; Trombotto, S.; Delair, T.; Sudre, G. Preparation of Highly Stable and Ultrasmooth Chemically Grafted Thin Films of Chitosan. Soft Matter2023. doi:10.1039/D3SM00003F.
• 6. Micciulla, S.; Gutfreund, P.; Kanduč, M.; Chiappisi, L. Pressure-Induced Phase Transitions of Nonionic Polymer Brushes. Macromolecules2023. doi:10.1021/acs.macromol.2c01979.
• 5. Niebuur, B.-J.; Chiappisi, L.; Jung, F. A.; Zhang, X.; Schulte, A.; Papadakis, C. M. Nanoscale Disintegration Kinetics of Mesoglobules in Aqueous Poly( N -Isopropylacrylamide) Solutions Revealed by Small-Angle Neutron Scattering and Pressure Jumps. Nanoscale2021, 13 (31), 13421–13426. doi:10.1039/D1NR02859F.
• 4. Niebuur, B.-J.; Ko, C.-H.; Zhang, X.; Claude, K.-L.; Chiappisi, L.; Schulte, A.; Papadakis, C. M. Pressure Dependence of the Cononsolvency Effect in Aqueous Poly( N -Isopropylacrylamide) Solutions: A SANS Study. Macromolecules 2020, 53 (10), 3946–3955. doi:10.1021/acs.macromol.0c00489
• 3. Micciulla, S.; Hayward, D.W.; Gerelli, Y.; Panzarella, A.; von Klitzing, R.; Gradzielski, M.; Chiappisi, L. One-step procedure for the preparation of functional polysaccharide/fatty acid multilayered coatings. Communications Chemistry, 1, 2019, 61. doi:10.1038/s42004-019-0155-y
• 2. B. Niebuur, L. Chiappisi, F. Jung, X. Zhang, A. Schulte, C. M. Papadakis Kinetics of Mesoglobule Formation and Growth in Aqueous Poly(N-isopropylacrylamide) Solutions: Pressure Jumps at Low and at High Pressure. Macromolecules, 52, 2019, 6416-6427. doi:10.1021/acs.macromol.9b00937
• 1. B.-J. Niebuur, L. Chiappisi, X. Zhang, F. Jung, A. Schulte, C.M. Papadakis Formation and Growth of Mesoglobules in Aqueous Poly( N -isopropylacrylamide) Solutions Revealed with Kinetic Small-Angle Neutron Scattering and Fast Pressure Jumps. ACS Macro Lett. 2018, 1155–1160. doi:10.1021/acsmacrolett.8b00605

Anyone who attempted to prepare mayonnaise, knows how difficult the mixing of water and oil can be. Nevertheless, the importance of mixing liquids at the microscale goes far beyond a culinary pleasure. In fact, micro-, nano-, or macro-emulsions are of exceptional technical relevance and continuous efforts are made to develop novel, cheap, environmentally friendly procedures to prepare emulsion systems. 

The most common approach foresees the use of surfactants and cosurfactants, which stabilize the interface between the two liquids. The components need to be selected for the target application of the system, and might carry stimuli-responsive properties which allow to adapt the systems properties. Oil and water can, however, be mixed also without the use of surfactant molecules. The so-called "surfactant-free emulsions" are based on the Ouzo-effect, i.e., the formation of a metastable emolsion when a three liquids, pairwise fully miscible, are mixed together. The effect is at the basis of the turbidity arising upon diluting the famous Greek spirit or the French Pastis.

Publications on this topic:

• 4.  Simon, M.; Krause, P.; Chiappisi, L.; Noirez, L.; Gradzielski, M. Structural Control of Polyelectrolyte/Microemulsion Droplet Complexes (PEMECs) with Different Polyacrylates. Chem. Sci.2019, 10 (2), 385–397. doi:10.1039/C8SC04013C.
• 3. L. Chiappisi, I. Grillo Looking into Limoncello: The Structure of the Italian Liquor Revealed by Small-Angle Neutron Scattering. ACS Omega. 3 2018, 15407–15415. doi:10.1021/acsomega.8b01858
• 2. Chiappisi, L.; Noirez, L.; Gradzielski, M. A Journey through the Phase Diagram of a Pharmaceutically Relevant Microemulsion System. J. Colloid Interface Sci. 2016, 473, 52–59. doi:10.1016/j.jcis.2016.03.064, Cover page here
• 1. Kaur, G.; Chiappisi, L.; Prévost, S.; Schweins, R.; Gradzielski, M.; Mehta, S. K. Probing the Microstructure of Nonionic Microemulsions with Ethyl Oleate by Viscosity, ROESY, DLS, SANS, and Cyclic Voltammetry. Langmuir 2012, 28, 10640–52. doi:10.1021/la300540d

In our research activity, our limits are often set by missing sample environments or the inability of treating the collecting data. Part of my research activity aims at overcoming such limitations. Progress might be brought by novel approaches of data analysis, by providing the computational tools for data treatment, or in the design of new sample enviroments.

Publications on this topic:

• 9. Lamolinairie, J.; Dollet, B.; Bridot, J.-L.; Bauduin, P.; Diat, O.; Chiappisi, L. Probing Foams from the Nanometer to the Millimeter Scale by Coupling Small-Angle Neutron Scattering, Imaging, and Electrical Conductivity Measurements. Soft Matter2022. doi:10.1039/D2SM01252A.
• 8. Kühnhammer, M.; Braun, L.; Ludwig, M.; Soltwedel, O.; Chiappisi, L.; von Klitzing, R. A New Model to Describe Small-Angle Neutron Scattering from Foams. J. Appl. Crystallogr.2022, 55 (4). doi:10.1107/S1600576722004691.
• 7. Cisse, A.; Peters, J. ; Lazzara, G.; Chiappisi, L.. PyDSC: a simple tool to treat differential scanning calorimetry data, J. Therm. Anal. Calorim. 2020, doi:10.1007/s10973-020-09775-9.
• 6. Chiappisi, L. Structural Characterization of Clay Systems by Small-Angle Scattering. In Clay Nanoparticles; Elsevier, 2020; pp 37–65. doi:10.1016/b978-0-12-816783-0.00002-5
• 5. B.-J. Niebuur, L. Chiappisi, X. Zhang, F. Jung, A. Schulte, C.M. Papadakis Formation and Growth of Mesoglobules in Aqueous Poly( N -isopropylacrylamide) Solutions Revealed with Kinetic Small-Angle Neutron Scattering and Fast Pressure Jumps. ACS Macro Lett. 2018, 1155–1160. doi:10.1021/acsmacrolett.8b00605
• 4. Hayward, D. W.; Chiappisi, L.; Prévost, S.; Schweins, R.; Gradzielski, M. A Small-Angle Neutron Scattering Environment for In-Situ Observation of Chemical Processes. Sci. Rep. 2018, 8 (1), 7299. doi:10.1038/s41598-018-24718-zDownload
• 3. Chiappisi, L.; Prévost, S.; Gradzielski, M. Form factor of cylindrical superstructures composed of globular particles. Journal of Applied Crystallography. 2014, 47, 827-834. doi:10.1107/S1600576714005524
• 2. Chiappisi, L.; Li, D.; Wagner, N. J.; Gradzielski, M. An improved method for analyzing isothermal titration calorimetry data from oppositely charged surfactant polyelectrolyte mixtures. Journal of Chemical Thermodynamics 2014, 68, 48–52. doi:10.1016/j.jct.2013.08.027
• 1. Chiappisi, L.; Lazzara, G.; Milioto, S.; Gradzielski, M. A quantitative description of temperature induced self-aggregation thermograms determined by differential scanning calorimetry. Langmuir 2012, 28, 17609–17616. doi:10.1021/la303599d