Giulia Fredi

Università degli Studi di Trento | UNITN · Department of Industrial Engineering

The current paper proposes a novel analytical micromechanics model to progressively predict the mechanical behavior of composites reinforced by continuous or discontinuous aligned fibers considering the nonlinear mechanical behavior of components and statistical breakage of fiber bundles based on the Curtin model. The PA6-based Single polymer compo...

The present study reports on the development of a new binary filler system for rubber composites, SiO 2 @Al 2 O 3 , where Al 2 O 3 sheets are grown onto SiO 2 nanoparticles aggregates by a sustainable water‐based soft‐chemistry approach. The aim is to synergistically integrate the intrinsic thermal conductivity properties of Al 2 O 3 with the pecul...

Friction-induced vibrations in an automotive braking system are of serious concern, leading to different repercussions. Numerous conventional and unconventional methods have been proposed to curb these vibrations, which are also observed to be directly related to generating non-exhaust particulate matter emissions. In this study, an in-house formul...

In the last century, global primary energy consumption and related CO2 emissions increased 10 times, and they are still on the rise. The environmental sustainability and the limitation of the energy consumption of buildings are of substantial importance in reducing greenhouse gas emissions and mitigating the consequences of climate change. The main...

The development of fully renewable and biodegradable composites for short-term applications was pursued by combining a compatibilized poly(lactic acid) (PLA)/poly(butylene succinate-co-adipate) (PBSA) (60:40 wt:wt) blend with coffee silver skin (CSS), an industrial byproduct from coffee processing. An epoxy-based reactive agent (Joncryl ADR-4468) w...

Biopolymers from renewable bio-based resources provide a sustainable alternative to petroleum-derived plastics, but limitations like brittleness and cost restrict applicability. Blending offers an affordable route to combine the advantages of different biopolymers for tailored performance. However, most biopolymer pairs are intrinsically immiscible...

Ladder-like poly(methacryloxypropyl)-silsesquioxanes (LPMASQ) are photocurable Si-based gels characterized by a double-stranded structure that ensures superior thermal stability and mechanical properties than common organic polymers. In this work, these attractive features were exploited to produce, in combination with alumina nanoparticles (NPs),...

The recent interest in multifunctional materials with tailorable performances led to the formulation of novel polymer blends, with enhanced properties with respect to traditional plastics and showing economical advantages compared to the synthesis of new polymers. However, polymer blends are immiscible in most cases, and proper compatibilization is...

Fused Filament Fabrication (FFF) is a 3D‐printing technique that enables the production of complex geometries with a high level of customization at low cost. The poor mechanical properties of FFF‐printed parts often undermine the application of this technology for structural purposes. To overcome this limitation, a two‐step metallization method is...

This work presents the successful preparation and characterization of polylactide/poly(propylene 2,5-furandicarboxylate) (PLA/PPF) and polylactide/poly(butylene 2,5-furandicarboxylate) (PLA/PBF) blends in form of bulk and fiber samples and investigates the influence of poly(alkylene furanoate) (PAF) concentration (0 to 20 wt%) and compatibilization...

Sustainable and bioderived furanoate polyesters are emerging as promising substitutes for petrochemical-derived polyesters, which are mainly applied in packaging, textile, and biomedical applications. This work presents the successful production, for the first time, of electrospun nanofibrous mats based on two furan-based polyesters, i.e., poly(but...

Ethylene Propylene Diene Monomer (EPDM) rubber foams are widely employed for thermal and acoustic insulation in building construction. However, their installation in confined spaces is often complicated, and the capability of EPDM foams to exhibit shape memory behavior could be a desirable property. In the literature, several works have demonstrate...

Type-1 diabetes is one of the most prevalent metabolic disorders worldwide. It results in a significant lack of insulin production by the pancreas and the ensuing hyperglycemia, which needs to be regulated through a tailored administration of insulin throughout the day. Recent studies have shown great advancements in developing an implantable artif...

Recently, drug personalization has received noticeable attention. Problems arising from standard generalized drug treatments have aroused over the years, particularly among pediatric and geriatric patients. The growing awareness of the limitations of the “one‐size‐fits‐all” approach has progressively led to a rethinking of the current medicine's de...

The interesting thermomechanical properties of rubber materials have favored their widespread application in many fields, with a consequent increase in the amount of worn synthetic and natural rubber discarded every year. However, the complex three-dimensional molecular structure of rubber complicates the recycling and degradation process, and the...

Organic phase change materials, e.g., paraffins, are attracting increasing attention in thermal energy storage (TES) and thermal management applications. However, they also manifest interesting optical properties such as thermotropism, as they can switch from optically opaque to transparent reversibly and promptly at the melting temperature. This w...

This work aims at preparing bioderived polymer films by blending poly(lactic) acid (PLA) and poly(dodecylene 2,5‐furandicarboxylate) (PDoF) and containing reduced graphene oxide (rGO) as a multifunctional filler in variable weight fraction (from 0.25 to 2 phr). Although the PLA/PDoF blend results as immiscible, the addition of rGO leads to smaller...

In this paper Ethylene Propylene Diene Monomer rubber (EPDM) foams were filled with different amounts of paraffin, a common phase change material (PCM) having a melting temperature at about 70 °C, to develop novel rubber foams with thermal energy storage (TES) capabilities. Samples were prepared by melt compounding and hot pressing, and the effects...

Despite the advantages of polylactide (PLA), its inadequate UV-shielding and gas-barrier properties undermine its wide application as a flexible packaging film for perishable items. These issues are addressed in this work by investigating the properties of melt-mixed, fully bioderived blends of polylactide (PLA) and poly(ethylene furanoate) (PEF),...

This work reports on an environmentally friendly method to produce encapsulated phase change material with a thin nickel coating, applicable for heat conversion, storage and thermal management of heat-sensitive components and suitable for active heating by electromagnetic radiation. A critical issue for the metallization is the adhesion between the...

Thermal energy storage (TES) with phase change materials (PCMs) presents some advantages when shape‐stabilization is performed with ceramic aerogels. These low‐density and ultra‐porous materials guarantee high energy density and can be easily regenerated through simple pyrolysis while accounting for moderate mechanical properties. However, the smal...

This work aims to produce poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAF)s fiber blends for textile applications and evaluates their microstructural, chemical, thermal, and mechanical properties. The work focuses on two PAFs with very different alkyl chain lengths, i.e., poly(ethylene 2,5−furandicarboxylate) (PEF) and poly(dodecamethylene 2...

Through this editorial, we aim to present the main aspects related to the scientific contributions that can be found in the Special Issue dedicated to the topic “Investigation of Polymer Nanocomposites’ Performance” [...]

Polylactide (PLA) is the most widely used biopolymer, but its poor ductility and scarce gas barrier properties limit its applications in the packaging field. In this work, for the first time, the properties of PLA solvent-cast films are improved by the addition of a second biopolymer, i.e., poly(decamethylene 2,5-furandicarboxylate) (PDeF), added i...

Drawing is a well-established method to improve the mechanical properties of wet-spun fibers, as it orients the polymer chains, increases the chain density, and homogenizes the microstructure. This work aims to investigate how drawing variables, such as the draw ratio, drawing speed, and temperature affect the elastic modulus (E) and the strain at...

The skin delivery of poorly soluble drugs represents a problem especially for formulations with limited residence time for which a low amount of drug is released with consequent inefficacy of the therapy. Many purposed approaches suggest the use of nanocarriers as liposomes, micro/nanoparticles or cyclodextrins to solve this problem. This study aim...

This work aims at producing and investigating, for the first time, the microstructural and thermo-mechanical properties of fibers constituted by poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAFs) blends for textile applications. Two different PAFs have been investigated, i.e., poly(octylene furanoate) (P8F) and poly(dodecylene furanoate) (P12...

Fibroin monoliths, produced by compression molding starting from the protein powder, are known to achieve an impressive mechanical strength when tested in dry conditions. However, in the presence of water, the loss of structural integrity and mechanical per- formances is striking. Considering the bone scaffold applications for which this material i...

Furanoate polyesters are emerging as promising bioderived polymers that could replace petrochemical‐derived polyesters in several applications, for example, the textile field. Here, sustainable and fully bioderived fibers are wet‐spun by blending poly(lactic acid) (PLA) and poly(pentamethylene 2,5‐furanoate) (PPeF), with up to 50 wt% of PPeF. PLA/P...

The simultaneous need for high specific mechanical properties and thermal energy storage (TES) function, present in several applications (e.g., electric vehicles), can be effectively addressed by multifunctional polymer-matrix composites containing a reinforcing agent and a phase change material (PCM). The PCMs generally decrease the mechanical pro...

Phase change materials (PCMs) in the form of fibers or fibrous mats with exceptional thermal energy storage ability and tunable working temperature are of high interest to produce smart thermoregulating textiles, useful for increasing human thermal comfort while avoiding energy waste. Common organic PCMs suffer from instability in their molten stat...

Epoxy/hollow glass microsphere (HGM) syntactic foams (SFs) are peculiar materials developed to combine low density, low thermal conductivity, and elevated mechanical properties. In this work, multifunctional SFs endowed with both structural and thermal management properties were produced for the first time, by combining an epoxy matrix with HGM and...

Replacing conventional plastics with bioplastics, i.e., plastics that are bioderived and/or biodegradable, does not necessarily solve the issues of resource depletion and plastic waste accumulation. To come to a truly sustainable plastics economy, the growing bioplastics production must be paralleled with effective end-of-life strategies for biopla...

Syntactic foams (SFs) combining an epoxy resin and hollow glass microspheres (HGM) feature a unique combination of low density, high mechanical properties, and low thermal conductivity which can be tuned according to specific applications. In this work, the versatility of epoxy/HGM SFs was further expanded by adding a microencapsulated phase change...

This work reports on the first attempt to prepare bioderived polymer films by blending polylactic acid (PLA) and poly(dodecylene furanoate) (PDoF). This blend, containing 10 wt% PDoF, was filled with reduced graphene oxide (rGO) in variable weight fractions (from 0.25 to 2 phr), and the resulting nanocomposites were characterized to assess their mi...

To favor a transition toward a more sustainable society, it is fundamental to find renewable and effective alternatives to current packaging materials. Here, fully renewable polymer films are produced by blending poly(lactic acid) (PLA) and poly(alkylene furanoate)s (PAFs). The work aims at discussing their microstructural and thermomechanical prop...

This study explores the co-deposition of thin polymeric films loaded with nanoparticles for its possible future application as radiation detectors. Thin films containing zinc oxide (ZnO) nanoparticles in plasma polymerized n-hexane (PPH) were deposited on silicon substrates using an atmospheric pressure plasma jet (APPJ). Crystalline ZnO nanopartic...

This work focuses on flexible epoxy (EP) composites containing various amounts of neat and polydopamine (PDA)-coated paraffin microcapsules as a phase change material (PCM), which have potential applications as adhesives or flexible interfaces with thermal management capability for electronics or other high-value-added fields. After PDA modificatio...

This review introduces the concept of thermal energy storage (TES) and phase change materials (PCMs), with a special focus on organic solid-liquid PCMs, their confinement methods and their thermal management (TM) applications al low-medium temperatures (0 • C-100 • C). It then investigates the approach of embedding TES and TM functionalities in str...

Thin cyclic olefin copolymer (COC) foils were used as intrinsic thermoplastic healing agents in carbon fiber (CF)-reinforced epoxy laminates. COC films were produced by hot pressing and were interleaved in the interlaminar regions between each EP/CF lamina, during the hand layup fabrication of the laminates. Three samples were produced, i.e., the n...

The present work investigates the microstructural, thermo-mechanical, and electrical properties of a promising, but still not thoroughly studied, biobased polymer, i.e., poly(decylene furanoate) (PDeF), and its performance when multi-walled carbon nanotubes (CNTs) are added. After sample preparation by solution mixing and film casting, the microstr...

Dynamic-mechanical analysis (DMA) was performed to investigate the viscoelastic response of multifunctional laminates for thermal energy storage (TES). The laminates were constituted by a microencapsulated paraffinic phase change material (PCM), a carbon fiber fabric, and an innovative reactive acrylic resin (Elium®). In the Elium®/PCM systems, the...

This work aims at producing and characterizing unidirectional carbon/epoxy composites containing different fractions of paraffin microcapsules (MC) for thermal management applications. The viscosity of the epoxy/MC mixtures increases with the MC content, thereby increasing the final matrix weight and volume fraction and reducing that of the fibers....

Microencapsulated phase change materials (PCMs) are attracting increasing attention as functional fillers in polymer matrices, to produce smart thermoregulating composites for applications in thermal energy storage (TES) and thermal management. In a polymer composite, the filler–matrix interfacial adhesion plays a fundamental role in the thermomech...

Microencapsulated phase change materials (PCMs) are being increasingly employed as functional fillers in polymer matrices for thermal management. Therefore, the effect of PCM microcapsules on the rheological, microstructural, thermal and mechanical properties of the host polymer matrices must be understood. This work concerned the preparation of ep...

The present work focuses on the development of polypropylene (PP) filaments containing paraffin microcapsules (MC), aimed at being incorporated in hybrid yarns to produce multifunctional thermoplastic laminates for thermal energy storage (TES). Benchmark experiments carried out on a small-scale melt compounder and piston-type melt spinning device r...

This work aims to study the synergistic effect of aluminum/magnesium hydroxide microfillers and organomodified fumed silica nanoparticles as flame retardants (FRs) for linear low-density polyethylene (LLDPE), and to select the best composition to produce a fire-resistant polyethylene-based single-polymer composite. The fillers were added to LLDPE a...

For the first time, multifunctional fully biodegradable composites combining structural and thermal energy storage/release capabilities were prepared and thermo-mechanically characterized. Within this scope, thin beech laminae impregnated with a phase change material (PCM) represented by poly(ethylene glycol) (PEG) were interleaved with thin foils...

Organic phase change materials (PCMs) represent an effective solution to manage intermittent energy sources as the solar thermal energy. This work aims at encapsulating docosane in organosilica shells and at dispersing the produced capsules in epoxy/carbon laminates to manufacture multifunctional structural composites for thermal energy storage (TE...

This work aims at developing multifunctional thermoplastic laminates combining structural and heat storage/management functions. The laminates are constituted by paraffin microcapsules as phase change materials (PCM), continuous carbon fibers, and a novel thermoplastic liquid methyl methacrylate resin (Elium), processable as a thermoset. The charac...

For the first time, multifunctional epoxy–short carbon fiber reinforced composites suitable for thermal energy storage technology were developed. Paraffin microcapsules (MC) and short carbon fibers (CFs) were added at different relative amounts to an epoxy matrix, and the microstructural and thermomechanical properties of the resulting materials we...

Video abstract of the paper "Graphitic microstructure and performance of carbon fibre Li-ion structural battery electrodes". You can also watch the abstract without downloading it, at http://iopscience.iop.org/article/10.1088/2399-7532/aab707

This work focuses on the development of multifunctional thermoplastic composites with thermal energy storage capability. A polyamide 12 (PA12) matrix was filled with a phase change material (PCM), constituted by paraffin microcapsules (Tmelt = 43 °C), and reinforced with carbon fibers (CFs) of two different lengths (chopped/CF “long”[CFL] and mille...

This work aims to investigate the fire performance of novel polyethylene-based single polymer composites. Fumed silica nanoparticles and magnesium hydroxide microfillers were added at an optimized concentration to a linear low-density polyethylene matrix, which was then reinforced with ultra-high molecular weight polyethylene fibers. Through the op...

Carbon fibres (CFs), originally made for use in structural composites, have also been demonstrated as high capacity Li-ion battery negative electrodes. Consequently, CFs can be used as structural electrodes; simultaneously carrying mechanical load and storing electrical energy in multifunctional structural batteries. To date, all CF microstructural...

This work aimed to study the combined effect of metal hydroxides and fumed silica in enhancing the fire-retardant properties of a polyethylene single-polymer composite. The LLDPE matrix was blended with fumed silica and aluminum or magnesium hydroxides in different weight fractions. The obtained matrices were characterized to select that with the b...

In this work a Polyamide 12 (PA12) matrix was melt compounded with different amounts of discontinuous carbon fibers with different length and encapsulated paraffin, in order to develop novel thermoplastic composites with thermal energy storage/release capability. The microstructural, thermal and mechanical properties of the resulting materials were...

Thermoplastic composite laminates with thermal energy storage (TES) capability were prepared by combining a glass fabric, a polyamide 12 (PA12) matrix and two different phase change materials (PCMs), i.e. a paraffinic wax microencapsulated in melamine-formaldehyde shells and a paraffin shape stabilized with carbon nanotubes. The melt flow index of...

This work is focused on the preparation and characterization of novel multifunctional structural composites with thermal energy storage (TES) capability. Structural laminates were obtained by combining an epoxy resin, a paraffinic phase change material (PCM) stabilized with carbon nanotubes (CNTs), and reinforcing carbon fibers. The stabilized par...

A paraffin wax was shape stabilized with 10 wt % of carbon nanotubes (CNTs) and dispersed in various concentrations in an epoxy resin to develop a novel blend with thermal energy storage capabilities. Thermogravimetric analysis showed that CNTs improve the thermal stability of paraffin, while differential scanning calorimetry showed that the paraff...