Luigi Gentile - OutBioPoly

Out-of-Equilibrium bio-based polymeric complex fluids (OutBioPoly)

Complex fluids play an emerging role in fundamental research and have wide-ranging medical and industrial uses, ranging from biological fluids and drug delivery to food, textile, and personal care products. Complex fluids manifest non-Newtonian rheological behavior, changing their structures and properties due to shearinduced supramolecular transitions, leading to large changes (shear-thinning or shear-thickening) in bulk viscosity. This project focus on an innovative high-throughput thermomechanical approach to induce supramolecular transitions in polymeric bio-based complex fluids, specifically, biopolymers in natural solvents. High shear rates will promote the formation of out-of-equilibrium structures. The aims are to understand the supramolecular transition mechanism, improve thermomechanical processes for regenerating materials, and ultimately produce materials with interesting properties for future applications. These materials may have novel applications ranging from shear-thickening bulletproof jackets or heat-resistant materials for aerospace to self-healing membranes.

Published works

Charge regulation in peptide self-assembly and hydrogelationThe peptide Ac-KGSFSIQYTYHVD-CONH₂ (KD), derived from residues 37–49 of human semenogelin I, forms a pH-responsive hydrogel in an aqueous environment …

Insights into the Hierarchical Assembly of a Chemically Diverse Peptide Hydrogel Derived from Human Semenogelin IA peptide corresponding to a 13-residue segment of the human protein semenogelin I has been shown to generate a hydrogel consisting of amyloid-like fibrils. The relative chemical diversity (compared to synthetic de novo sequences) with 11 distinct amino acids makes this peptide (P0) an ideal candidate for investigating the role of individual residues in gelation. Herein, the N-terminal residues have been sequentially removed to furnish a series of truncated peptides, P1–P10, ranging from 12 to 3 residues in length. FTIR spectroscopy investigations reveal that P0–P6 forms a β-sheet secondary structure while shorter sequences do not self-assemble. Site-specific isotope labeling of the amide backbone of P0–P2 with the IR-sensitive vibrational probe 13C═O yields FTIR spectra indicative of the initial formation of a kinetic product that slowly transforms into a structurally different thermodynamic product. The effects of the isotopic labels on the IR spectra facilitate the assignment of parallel and antiparallel structures, which are sometimes coexistent. Additional IR studies of three PheCN-labeled P0 sequences are consistent with an H-bonded β-sheet amide core, spanning the 7 central residues. The macromolecular assembly of peptides that form β-sheets was assessed by cryo-TEM, SAXS/WAXS, and rheology. Cryo-TEM images of peptides P1–P6 display μm-long nanofibrils. Peptides P0–P3 generate homogeneous hydrogels composed of colloidally stable nanofibrils, and P4–P6 undergo phase separation due to the accumulation of attractive interfibrillar interactions. Three amino acid residues, Ser39, Phe40, and Gln43, were identified to be of particular interest in the truncated peptide series as the removal of any one of them, as the sequence shortens, leads to a major change in material properties.

Shear and cooling effects on lamellar gel network structure: Insights from Rheo-SANSWe investigate the formation of lamellar gel networks (LGNs) composed of long-chain fatty alcohols (C16, C18) and their mixture, combined with the sur…

Morphological Influence on a Nonionic Bilayer Bending Rigidity and Compression ModulusThe mechanical properties of multilamellar vesicles and their relevance to soft matter physics and material science are of significant interest. The bending rigidity, κ, and compression modulus, B, of three-dimensional (3D) finite nonspontaneous multilamellar vesicles, formed by a nonionic surfactant, are linked to nanoscale bilayer thickness, δ, estimated via small-angle X-ray scattering, and macroscopic elastic modulus measured through small-amplitude oscillatory shear experiments. κ and B significantly differ from the same system in the two-dimensional (2D) infinite nanostructured planar lamellar phase. Particularly, κ3D was found to be much smaller than κ2D, while an opposite behavior was seen for B. The 2D-to-3D morphology transition occurs under a transient mechanical field, resulting in rheopectic behavior. κ scales quadratically with δ, consistent with bilayer membrane theories, and linearly with vesicle radius in the densely packed state. These findings have implications for understanding and designing soft interfaces due to the influence of bending rigidity on transport properties.

Adsorbent semi-transparent cellulose-based self-standing thin filmsCellulose-based materials are emerging as versatile candidates for sustainable functional materials. This study presents a straightforward process to …

Tetrabutylammonium hydroxide and zinc salts in cellulose-based colloidal systems enhance fruit shelf lifeThis study explores the development of cellulose-based active colloidal systems to enhance the antimicrobial properties of absorbent food pads and pro…

Enhanced benzothiazole removal from textiles with a polyglycoside/dodecanol formulation: Mechanisms of self-assembly and oil-uptake capacityThe design of surfactant formulations with tailored structural properties presents a promising approach for applications in drug delivery, oil absorpt…

Salt‐Induced Modulation of Self‐Assembly in C8‐10 AlkylPolyGlucoside/Fatty Alcohol FormulationsSalt's effect on the APG:1-Dodecanol system was studied. Small-angle X-ray scattering showed salt increased interparticle correlation, leading to higher structural organization at higher salt concent...

Talks

Gentile L., "Cellulose-based active materials: from semidilute unentangled solutions to films project" ECIS2024 38th Conference of the European Colloid & Interface Society- September 1-6, 2024 - Copenhagen (Denmark)

Gentile L. "Fabrication of regenerated cellulose films via out-of-equilibrium solvents" ACS Spring 2025, - March 23-237, 2025 - San Diego (USA) Presented during the Structure-Property Relationships in Biobased Polymers for Advanced Manufacturing: Joint Symposium of CELL/PMSE

Instrumentation

Small- and Wide-Angle X-ray Scattering (SAXS and WAXS)

SAXSpoint 2.0 - q-range from 0.02 nm^-1 to 40 nm^-1

Equipped with:

Shear-cell, Tensile

Electrospinning/Electrospraying Multi-Nozzle system

Equipped with:

Single High Voltage Power Supply Unit: 0-30kVolt

Syringe Heater

EFA150 Fume hood

Optical Microscope with polarizers

Equipped with:

63x

Under Delivery From Leica

Microfluidics Devices

Double pumps

Herringbone Mixer Chip and Y flowfocusing Chip

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