Miriam Scoti is Researcher of Industrial Chemistry in the Group of Polymer Physics and Macromolecular Chemistry (PPL) of Prof. Claudio De Rosa at the Department of Chemical Sciences of the University of Napoli Federico II.
Dr. Miriam Scoti graduated in Chemistry with honors in 2011 with a thesis entitled Structural characterization of isotactic propylene/pentene copolymers by wide angle and small angle X-ray diffraction. She earned her master’s degree in Chemical Sciences with honors in 2014 from the same University with a thesis entitled Synthesis, structure and physical properties of syndiotactic copolymers of propylene with 1-eicosene and 1-octadecene. She received her doctorate in Chemical Sciences in February 2018 from the same University with the thesis Novel polyolefin based elastomers with tailored stiffness from metallorganic catalysis: the crystalline elastomers.
RESEARCH, TEACHING, or OTHER INTERESTS
Polymers and Plastics, Materials Science, Chemistry, Materials Chemistry
Tacticity-independent crystallization of polymers Leire Sangroniz, Ainara Sangroniz, Changxia Shi, Miriam Scoti, Marta Ximenis, Claudio De Rosa, Eugene Y.-X. Chen, Haritz Sardon, Alejandro J. Müller Nature Chemistry, 2026
Unexpected Ductility Enhancement in Crystalline–Crystalline Polyolefin Diblock Copolymers without Introducing Soft Segments Rocco Di Girolamo, Miriam Scoti, Chiara Santillo, Claudio De Rosa Macromolecules, 2026 High Resolution Image Download MS PowerPoint Slide Combining polyethylene and polypropylene (isotactic or syndiotactic) crystalline blocks within a single macromolecule offers a powerful framework to elucidate how the molecular architecture governs deformation and phase transformations during stretching in polyolefins. In this study, polyethylene- block -isotactic-polypropylene (PE- b -iPP) and polyethylene- block -syndiotactic-polypropylene (PE- b -sPP) copolymers with well-defined block lengths, synthesized using single-site catalysts, were investigated to elucidate the relationship between molecular architecture, crystalline structure, and mechanical response. X-ray diffraction and tensile analyses revealed that despite the absence of amorphous soft segments, both block copolymers exhibit remarkable ductility enhancement compared to their corresponding homopolymers when a long iPP or sPP block is linked to a PE block. The mechanical performance strongly depends on the relative block lengths and the polymorphic transformations that occur during deformation. In PE- b -iPP samples, the α-form of iPP progressively transforms into the mesomorphic form under deformation, while in PE- b -sPP copolymers, the helical form I of sPP transforms into the trans -planar form III. These stress-induced transitions promote energy dissipation and delay fracture, enabling large deformations with pronounced strain hardening. The results demonstrate that high ductility in crystalline polyolefin block copolymers can be achieved in hard – hard systems through deformation-assisted polymorphic transitions, offering an alternative molecular design strategy without introducing soft segments for tough, extensible crystalline materials.
Silane-functionalized isotactic polypropylene: A direct route to advanced polyolefin materials Fabio De Stefano, Miriam Scoti, Angelo Giordano, Claudio De Rosa, Rocco Di Girolamo Materials Today Chemistry, 2026 Alkenylsilanes represent promising comonomers for the synthesis of functional polyolefins through direct catalytic copolymerization, preventing catalyst deactivation due to the weak interaction between the silicon atom and the metal center. However, their potential has been largely overlooked due to their tendency to undergo β-elimination, which leads to the formation of low-molecular-weight polymers with compromised material properties. We show that isotactic polypropylene-based copolymers with incorporated silane groups can be obtained by stereoselective Hf-catalysed copolymerization of propylene and allyltrimethylsilane (ATMS). These materials possess a random microstructure with ATMS contents ranging from 5.5 to 35.0 mol%. Contrary to the previously reported copolymerization of ATMS with α-olefins using metallocene catalysts, no involvement of ATMS in enhanced chain transfer rates could be detected and samples with high molecular weights were obtained ( M n > 600 kg/mol). The incorporation of bulky ATMS comonomer units leads to a significant reduction in the crystallinity of the copolymers compared to the iPP homopolymer, resulting in a markedly different mechanical response, characterized by enhanced flexibility and ductility compared to the brittle iPP. The possibility to tune the crystallinity, combined with the presence of functional comonomeric units, allows to obtain copolymers with a broad spectrum of properties, with glass transition temperatures ranging from subambient values to T g s approaching room temperature. Notably, at high ATMS contents, the copolymers exhibit exceptional elastic properties, which have been rationalized on the basis of the structural transformations occurring during deformation that involve the formation of a novel mesomorphic phase of iPP, which has not been previously reported in the literature. • Direct copolymerisation with allyltrimethylsilane enables functional isotactic polypropylene for advanced materials. • Silane functional groups incorporation up to 35 mol% achieved without enhanced chain transfer. • Tunable crystallinity and melting temperature allow property control from thermoplastic materials to elastic polymers. • A previously unreported mesomorphic phase of iPP identified at hight allyltrimethylsilane content.
Correlation between Orientation of Crystallites and Stress-Induced Phase Transformations in Copolymers of Isotactic Poly(Butene) with Ethylene Anna Malafronte, Miriam Scoti, Rocco Di Girolamo, Angelo Giordano, Fabio De Stefano, Claudio De Rosa Macromolecular Rapid Communications, 2026 The spontaneous transformation in isotactic poly(butene) (iPB) of kinetically favored form II into the thermodynamically stable form I at room temperature leads to dimensional instability due to changes of density and strength and has prevented industrial development of iPB. This transformation is accelerated by tensile deformation. This study investigates the correlation between the form II—form I transition occurring during tensile deformation and orientation of relative crystallites in 1‐butene/ethylene (C4C2) isotactic copolymers. During stretching, form II transforms into form I in all samples. Both the critical strain at which the form II‐to‐form I transition begins (ε c ) and the strain at which 50% of the initial form II is transformed into form I (ε 0.5 ) increase with increasing ethylene (C2) content. For samples with C2 content ≤ 7.6 mol%, form II crystals adopt an off‐axis orientation at ε 0.5 . In contrast, for higher C2 content, form II crystallites remain isotropic at ε 0.5 . Form I crystals adopt an off‐axis orientation at ε 0.5 only in the two samples with lowest C2 content (1.7 and 4.3 mol%). Crystals of form II and form I begin to orient in the standard fiber orientation at progressively earlier stages of the form II‐to‐form I transition as the ethylene content increases.
The Role of Stretching-Induced Phase Transformations in the Mechanical Properties of Isotactic 1-Butene-ethylene Copolymers from Ziegler–Natta Catalyst Anna Malafronte, Rocco Di Girolamo, Angelo Giordano, Fabio De Stefano, Miriam Scoti, Claudio De Rosa Macromolecules, 2025 High Resolution Image Download MS PowerPoint Slide The crystallization behavior and phase transformations occurring during deformation of random isotactic 1-butene-ethylene (C4C2) copolymers, synthesized with a Ziegler–Natta catalyst and characterized by an ethylene (C2) content between 1.7 and 16.3 mol %, were investigated using a combination of tensile testing and in situ wide-angle X-ray diffraction (WAXD) with synchrotron radiation. The phase transformations were correlated to the mechanical behavior. Samples with C2 content ≤7.6 mol % were basically crystallized in form II in their unstretched state, whereas samples with higher C2 contents were crystallized as a mixture of form II and form I′. During stretching, form II present in all the initial unoriented samples rapidly transforms into form I, indicating that uniaxial deformation significantly accelerates form II–form I transition, since in quiescent conditions, this transformation required longer times to complete. However, the effect of stretching on the form II–form I transition differs among the various copolymers. Specifically, the critical strain at which the form II–form I transition begins (ε c ) and the strain at which 50% of the initial form II transforms into form I (ε 0.5 ) increase with increasing C2 content. The quantitative analysis of WAXD data enabled the construction of a phase diagram for C4C2 copolymers, which identified the regions of stability of the various polymorphic forms as a function of ethylene content and deformation. In addition to the form II–form I transition, further crystallization of form I′ from the amorphous phase was observed during stretching of some samples. This study provides valuable structure–property information that is helpful for the design and application of this class of semicrystalline materials.
The Role of Intimate Dipole Carbonyl–Carbonyl and Hydrogen–Carbonyl Interactions in the Stereocomplexation and Crystallization: The Case of Poly(Cyclohexene Carbonate) Massimo Christian D'Alterio, Miriam Scoti, Rocco Di Girolamo, Giovanni Talarico, Geoffrey W. Coates, Claudio De Rosa Angewandte Chemie International Edition, 2025 Enantiopure isotactic poly(cyclohexene carbonate) (PCHC) has been synthesized with chiral Zn‐β‐diiminate catalyst. PCHC crystallizes both as enantiopure polymer (R)‐PCHC and (S)‐PCHC and upon stereocomplexation of the two enantiomers. We report the crystal structures of the enantiopure polymer and of the stereocomplex (R/S)‐PCHC and explain their crystallization based on the establishment of multiple attractive H‐‐‐O═C interactions between oxygen atoms of carbonyl groups and the hydrogen atoms of the cyclohexyl rings and C═O‐‐‐C═O intimate dipole interactions between carbonyl groups of chains of opposite chirality in the stereocomplex. The crystal structure of the enantiopure polymer is characterized by chains in 2/1 helical conformation packed in the orthorhombic unit cell with axes a = 11.55 Å, b = 9.42 Å, and c = 7.36 Å, according to the space group P212121, with steric interdigitation between chains of similar chirality favored by multiple attractive H‐‐‐O═C interactions. The stereocomplex crystallizes in an orthorhombic unit cell with axes a = 10.40 Å, b = 8.41 Å, and c = 7.36 Å, according to the space group Pbc21, driven by establishment of additional C═O‐‐‐C═O dipole interactions between carbonyl groups of chains of opposite chirality, besides of the multiple attractive H‐‐‐O═C interactions.
Fungal Chitin Nanofibrils to Improve the Functional Properties of Poly(vinyl alcohol) Films for Sustainable Food Packaging Md Shafi Alam, Leire Sangroniz, Miriam Scoti, Alba Gonzalez, Agustin Etxeberria, Ainara Sangroniz, Erlantz Lizundia ACS Applied Bio Materials, 2025 Food packaging films containing biobased fillers can offer improved functional properties while meeting current environmental sustainability requirements for a circular and sustainable society. In this work, biocomposites based on chitin nanofibers and PVA have been developed in order to improve the mechanical performance and water barrier properties, performing for the first time a life cycle assessment. The biocolloids employed are chitin nanofibrils (ChNFs) from fungi, an underutilized renewable carbon feedstock in packaging, which are more environmentally friendly than conventional ChNFs obtained from crustaceans. Free-standing nanocomposite films are obtained by solvent casting, using water as the sole solvent. The incorporation of ChNFs results in a mechanical reinforcing effect of PVA that increases the Young modulus. The water vapor barrier character of PVA is significantly enhanced by the presence of ChNFs, which is decreased by 70% upon the incorporation of 10% ChNFs, overcoming one of the most significant drawbacks of PVA. The nanocomposites maintain an excellent oxygen barrier character under high relative humidity. Life cycle assessment (LCA) reveals a global warming potential of 5.0–5.2 kg·CO 2 equiv·kg –1 for PVA/ChNFs films, demonstrating clear environmental benefits of the incorporation of ChNFs when considering the final properties. Overall, this work highlights the potential of fungal ChNFs to improve the mechanical properties and significantly improve the water barrier character of PVA, overcoming one of the limitations of this material in a sustainable way, as demonstrated by LCA.
Fabrication and structural analyses of electrospun syndiotactic propylene-ethylene copolymer nanofibers Fuyuaki Endo, Rocco Di Girolamo, Giovanni Talarico, Miriam Scoti, Naruki Kurokawa, Atsushi Hotta Polymer, 2025 ABSTRACT Fabrication and structural characterization of syndiotactic propylene-ethylene (sPPEt) copolymer nanofibers were conducted. When using a mixture of methylcyclohexane/DMF/acetone (8:1:1 (wt/wt)) as a solvent, semi-crystalline sPPEt copolymers with ethylene compositions ranging from 1.9 to 11.8 mol% were successfully fabricated into nanofibers via electrospinning. Copolymerization of sPP with ethylene significantly promoted the formation of thinner and smoother nanofibers by suppressing gelation of the spinning solution, thereby enhancing the electrospinnability of the sPP-based copolymer. FTIR and X-ray structural analyses on sPPEt nanofiber membranes revealed that the electrostatic stretching force during the electrospinning process led to a larger proportion of syndiotactic propylene units in the trans-planar conformation and the resulting formation of mesomorphic form crystals, similar to what has been observed during mechanical stretching and subsequent relaxation.
Propylene-Ethylene Copolymers from Supported Metallocene Catalysts: A Route to Span Properties from Polypropylene to Polyethylene Angelo Giordano, Fabio De Stefano, Rocco Di Girolamo, Anna Perfetto, Miriam Scoti, Claudio De Rosa Macromolecules, 2025 Propylene–ethylene copolymers with isotactic propylene sequences were synthesized across the entire range of comonomer composition, from 0.4 to 84 wt % of ethylene (C2), using a stereoselective supported metallocene catalyst. Propylene-rich copolymers crystallize in the α or γ forms of isotactic polypropylene (iPP), whereas ethylene-rich copolymers with C2 concentrations ranging from 65 to 84 wt % crystallize in the stable orthorhombic form of polyethylene (PE). Samples with C2 concentrations between 20 and 60 wt % are amorphous. Copolymers with C2 concentrations lower than 1–2 wt % are stiff and brittle materials that transform into highly flexible and ductile materials with variable strength as the C2 concentration increases up to 16 wt %. Amorphous samples with C2 concentration ranging from 20 to 60 wt % show easy deformability and low strength, sometimes associated with viscous flow. However, strength and ductility increase again with increasing C2 concentrations from 60 to 84 wt % in samples showing PE crystallinity. Remarkable elastic properties develop for C2 concentrations between 10 and 16 wt % and between 50 and 65 wt %. The outstanding mechanical properties and elastic behavior are attributed to phase transformations and crystallization occurring during deformation. Amorphous samples crystallize upon stretching in the pseudohexagonal form of PE, and these crystals act as knots within the amorphous network, preventing viscous flow and inducing the development of elastic properties. The synthetic strategy, based on the use of a supported metallocene catalyst, enables the retention of high molecular mass and uniform comonomer concentration across the entire composition range. This approach allows for the definition of materials with properties spanning from polypropylene to polyethylene and from rigid plastomers to elastomers. The crystallization behavior and mechanical properties of these materials are compared with those of industrially practiced systems produced using Ziegler–Natta catalysts, providing evidence for the unique or superior performance of the metallocene-based copolymers within specific composition ranges.
Crystal Structure of Poly(7-heptalactone) Anna Malafronte, Miriam Scoti, Maria Rosaria Caputo, Bo Li, Rachel K. O’ Reilly, Andrew P. Dove, Alejandro J. Müller, Claudio De Rosa Macromolecules, 2023
