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Cu-substituted Ni ferrite systems are produced following a hydrothermal synthetic route carried out at relatively mild conditions (i.e., below 200 °C). Different degrees of substitution were investigated, ranging from bare Ni ferrite to a complete Cu-substituted system (by replacing 100% of Ni with Cu). Morphological and structural characterisations point out that the introduction of Cu in the Ni ferrite (below 50% substitution) causes a gradual reduction of the average diameter of the ferrite polyhedral nanoparticles maintaining the Ni ferrite structure. At higher content of Cu, instead, the morphology evolves toward the co-presence of iron oxides (magnetite and hematite) and copper oxide (tenorite), without the formation of bare Cu ferrite. The partially substituted Ni ferrite nanomaterials exhibit a mostly superparamagnetic behaviour in all samples, registering a reduction of the values of magnetisation saturation by increasing the Cu content. Transmission Mössbauer spectroscopy performed on these nanomaterials evidenced a gradual lowering of the Fe fraction occupying the octahedral sites and a consequent increment of the Fe fraction in the tetrahedral sites. Quantitative analysis confirms the gradual reduction of the Ni content within the ferrite samples, coupled with the opposite increment of the Cu content, whereas the Fe content is lower in the case of Ni75-Cu25 sample. This particular behaviour can be associated with the influence of Cu substitution in the Ni ferrite structure, with preferential replacement of Fe from the octahedral B-sites toward the tetrahedral A-sites.

The ability of modifying the surface of a given substrate to confer novel “smart” properties only at the surface level is an extremely powerful approach as it allows to introduce specific physical, chemical, or biological characteristics able to favour an increment of the performances compared to the starting substrate. This is particularly true in the case of textiles and fibres, which are largely adopted not only in the textile field, but also in many innovative applications where the surface functionalisation plays a key role [1]. In this context, the first part of the talk will provide an overview over the use of textiles in surgical operations for the hernia care, with a focus on the possibility of using surface treatments to modify non-absorbable synthetic polymeric meshes to confer advanced features. In particular, the introduction of bioresorbable coatings able to exert an in situ antibacterial action is a very promising and widely investigated route to follow as one of the main issues related to the use of fully-absorbable fibres is their poor mechanical properties, which can be overcome by the presence of a bioinert non-absorbable skeletal materials, thus making the combination of both novel absorbable coatings and standard bioinert fibres a better compromise [2-3]. Another (often underestimated) concern related to hernioplasty is the shrinking of the prosthesis after implantation, with consequent collapse of the anchoring sutures through the hernia defect margin. Even here, the possibility of introducing a functional coating able to increase the adhesion ability of the prosthesis to the human tissue is a very promising technological solution alternative to the deposition of biocompatible glue on the meshes during the surgical intervention [4-5]. In the second part of the talk, a brief survey of representative case studies involving the surface modification of textiles for different applications will be discussed, including the modification of natural fibr

In recent years, significant efforts have been made in view of a transition from a linear to a circular economy, where the value of products, materials, resources, and waste is maintained as long as possible in the economy. The re-utilization of industrial and agricultural waste into value-added products, such as nanostructured siliceous materials, has become a challenging topic as an effective strategy in waste management and a sustainable model aimed to limit the use of landfill, conserve natural resources, and reduce the use of harmful substances. In light of these considerations, nanoporous silica has attracted attention in various applications owing to the tunable pore dimensions, high specific surface areas, tailorable structure, and facile post-functionalization. In this review, recent progress on the synthesis of siliceous materials from different types of waste is presented, analyzing the factors influencing the size and morphology of the final product, alongside different synthetic methods used to impart specific porosity. Applications in the fields of wastewater/gas treatment and catalysis are discussed, focusing on process feasibility in large-scale productions.

One of the main relevant limitations of the use of polymer-based materials in modern technological applications (e.g., electronics and optoelectronics, photonics, automotive) is their intrinsic low thermal conductivity that does not allow polymers to counteract the occurrence of the thermal degradation due to the in-service overheating phenomenon. To overcome this thermal constraint, polymer-based materials containing highly thermally conductive fillers are receiving great attention as they show an improved heat dissipation ability. However, recent studies report that a significant improvement of thermal conductivity in polymeric nanocomposites can be achieved only at high filler loadings, but this negatively affects both the mechanical behavior and density of the materials. Moreover, to achieve an efficient heat management, a continuous network of thermally conductive fillers crossing the entire composite is mandatory. In this context, interfacial phenomena play a major role as they favor the homogeneous distribution of the conductive fillers within the polymer matrix. In a previous study, it has been already verified that the surface functionalization of inorganic fillers (i.e., silica) with Polyhedral Oligosilsesquioxane (POSS) units, a family of hybrid inorganic-organic systems composed of an inorganic core of cage-like silicon oxide and several organic functional groups, significantly improved the dispersion and compatibilization of the inorganic fillers in the polymer matrix. Hence, the present contribution reports on the recent results obtained by introducing different types of alumina-based hybrid fillers decorated at the surface with either metacrylate silane or octa-methacryl-POSS units at low filler loadings in a polybutadiene polymer matrix. Even if displaying a modest intrinsic thermal conductivity, alumina can represent a valid and appealing thermally conductive filler, due to its low cost, stable chemical performance and negligible toxicity. The promi

The incorporation of silica nanoparticles (Si-NPs) into the polymer matrix is a growing area of interest research to produce high-performance polymer nanocomposites (NCs) across a wide range of nanotechnology applications. This improvement is due to the Si-NPs capability to self-assembly giving rise to specific well-organized structures with both short- and long-range order across a hierarchy of spatial scales, determined by both NP-NP and NP-matrix interactions, involving a careful balance among attractive driving forces, repulsive forces, and directional forces. Respect to this, the aim of the present paper is to systematically review the use of Si-NPs in polymer NCs and on the role of NPs self-assembly in determining the final material properties. Firstly, we explored the synthesis and modification of both isotropic and anisotropic Si-NPs in relation with use in NC materials, focusing on NPs dispersion and distribution, as well as on the functionalization strategies of Si-NPs. Besides Si-NPs functionalization with conventional small organic molecules, a large section is devoted to an emerging class of functionalized Si-NPs with macromolecules, namely silica hairy NPs (Si-HNPs), able to give rise a rich variety of complex assemblies and materials with new structures and functionalities. Successively, NCs materials containing Si-NPs and Si-HNPs have been explored in terms of synthetic preparation and properties. The self-organization of Si-NPs and Si-HNPs in polymer matrices has been reported and its effect on the functional materials properties have been evaluated with a critical point of view on the results, limits, and future perspectives. Our review can be considered a tutorial work, aiming at providing useful insights to researchers in the field of nanotechnology and nanoscience, taking into consideration the fundamental role of NPs self-assembly processes in determining the functional material properties.

The present study reports on the development and exploitation of an original filler system, based on alumina nanoparticles (NPs) and polyhedral silsesquioxane (POSS) units, namely Al2O3@POSS, where the remarkable compatibilization and thermomechanical features imparted by the silsesquioxane cage units “makes an alliance” with the enhanced thermal conductivity of Al2O3 NPs. The target is to supply rubber nanocomposites with improved heat transport and mechanical properties potentially applicable in tires formulation. The hybrid filler was prepared by a double-step approach consisting of a first silanization of Al2O3 with a methacrylate silane and subsequent grafting of OctaMethacrylPOSS through a radical reaction mediated by dicumyl peroxide as radical initiator. The material was characterized in depth in terms of structure, surface, and morphology and then used for producing, by solvent-casting technique, polybutadiene composites. The idea is to supply and test a model alumina-rubber based system which allows to better unveil the role played by the silsesquioxane units, thanks to the absence of other components (i.e. rubber polymers, vulcanization curatives and filler) usually included in real rubber formulations for tires. The comprehensive thermomechanical and morphological characterization of the nanocomposites highlighted the key role played by POSS units decorating the alumina surface, which assure both the compatibility between filler and polymer host, and an homogeneous distribution and continuous networking of the alumina NPs. This positively influences not only the heat transport, providing thermal conductive pathways that raise the thermal diffusivity even at low filler loadings (+60–70% with respect to composite enclosing bare alumina at a concentration of 15–10 v/v %) but also the storage modulus, paving the way toward a potential exploitation of Al2O3@POSS hybrid filler in large-scale formulations of rubber composites, namely those employed for tires.

In this chapter, the main advances in the valorization of shellfish derived biowaste are critically analyzed. The current European policy on (bio)waste management as well as the economy behind the European shellfish industry market (i.e., fundamental for the comprehension of the volumes of available biomass) are both introduced, providing a classification of the principal European shellfish products. Later, the chemical and structural composition of bivalves, cephalopods, and crustaceans shells is explained. Furthermore, the main relevant processes applicable to the shellfish solid waste for the isolation of useful chemicals are presented, with a view to propose a biorefinery model based on the most promising shellfish derived products, namely chitin and chitosan. Lastly, the technological applications of shellfish-derived products in the agri-food industry and in environmental clean-up processes are critically examined, and the most relevant literature discussed. Concerning the environmental applications, particular emphasis is dedicated to the challenging “waste for cleaning waste” vision. Analogously, the direct use of shellfish derived products in the agri-food industry is presented as an effective example of smart circular recycling.

Even if cement is a well-consolidated material, the chemistry of cement (and the chemistry inside cement) remains very complex and still non-obvious. What is sure is that the hydration mechanism plays a pivotal role in the development of cements with specific final chemical compositions, mechanical properties, and porosities. This document provides a survey of the chemistry behind such inorganic material. The text has been organized into five parts describing: (i) the manufacture process of Portland cement, (ii) the chemical composition and hydration reactions involving a Portland cement, (iii) the mechanisms of setting, (iv) the classification of the different types of porosities available in a cement, with particular attention given to the role of water in driving the formation of pores, and (v) the recent findings on the use of recycled waste materials in cementitious matrices, with a particular focus on the sustainable development of cementitious formulations. From this study, the influence of water on the main relevant chemical transformations occurring in cement clearly emerged, with the formation of specific intermediates/products that might affect the final chemical composition of cements. Within the text, a clear distinction between setting and hardening has been provided. The physical/structural role of water in influencing the porosities in cements has been analyzed, making a correlation between types of bound water and porosities. Lastly, some considerations on the recent trends in the sustainable reuse of waste materials to form “green” cementitious composites has been discussed and future considerations proposed.

Waste management is a most current topic, and as such, numerous articles in literature discuss over the recycling and re-use of waste materials from various fields. A common solution is the to use these materials as partial substituent of the inert fraction in concretes and mortars. This work focuses on the possibility of using Acanthocardia tuberculata seashells, which constitute a food waste destined to landfilling, as partial substituents of inert in mortars. The results obtained evidenced that the reduction in mechanical properties (in terms of toughness and flexural stress) is mainly due to the water absorption properties of seashells aggregates, which affect the hydration of the cement. However, as experimentally demonstrated, such decrease in mechanical properties in any case does not compromise the performance of the material when used for civil applications.

The continuous research of new functional materials combining both advanced properties and increased sustainability has dramatically risen up in the last decades. Instead of searching for new solutions, composites (formed by a combination of already present materials) are subject of different studies due to their capability of merging the advantages of components. Hence, chitosan, a biowaste-derived biopolymer, has been thermally-converted into chars by pyrolysis treatment. Subsequently, both chitosan and its char are introduced into cementitious matrix forming cement-based composites. The analysis of the mechanical properties of these materials evidenced that char-containing composites show an incipient fracture toughness capability, very appealing for possible structural applications.

The lack of robust and low-cost sorbent materials still represents a formidable technological barrier for long-term storage of (renewable) thermal energy and more generally for Adsorptive Heat Transformations—AHT. In this work, we introduce a novel approach for synthesizing cement-based composite sorbent materials. In fact, considering the number of available hygrosopic salts that can be accommodated into a cementitious matrix—whose morphological properties can be also fine-tuned—the new proposed in situ synthesis paves the way to the generation of an entire new class of possible sorbents for AHT. Here, solely focusing on magnesium sulfate in a class G cement matrix, we show preliminary morphological, mechanical and calorimetric characterization of sub-optimal material samples. Our analysis enables us to theoretically estimate one of the most important figures of merit for the considered applications, namely the energy density which was found to range within 0.088–0.2 GJ/m3 (for the best tested sample) under reasonable operating conditions for space heating applications and temperate climate. The above estimates are found to be lower than other composite materials in the literature. Nonetheless, although no special material optimization has been implemented, our samples already compare favourably with most of the known materials in terms of specific cost of stored energy. Finally, an interesting aspect is found in the ageing tests under water sorption-desorption cycling, where a negligible variation in the adsorption capability is demonstrated after over one-hundred cycles.

Heterogeneous processes based on the application of hybrid inorganic-organic magnet-responsive nanomaterials (MRNs) are receiving great attention in wastewater remediation treatments as alternative technologies exploitable both in light-enhanced advanced oxidation processes (AOPs), and in more traditional sorption routes. Such MRNs are based on magnetite/maghemite nanoparticles functionalized by two different biowaste-derived macromolecules (i.e., either humic-like substances or chitosan), following the "Waste Cleaning Waste" approach. In view of showing the potentiality of these hybrid systems, three case studies are discussed, namely: i) the removal of caffeine via light-enhanced AOPs at circumneutral conditions [1], the removal of anthracene and naphthalene via sorption mechanism [2], and the removal of As(III) and As(V) via sorption mechanism [3]. References: [1] F. Franzoso, et al., Chemical Engineering Journal 2017, 310, 307-316. [2] R. Nisticò, et al., ACS Sustainable Chemistry and Engineering 2017, 5, 793-801. [3] R. Nisticò, et al., Journal of Hazardous Materials 2018, 342, 260-269.

In recent years, a great interest has arisen around the integration of naturally occurring clays into a plethora of advanced technological applications, quite far from the typical fabrication of traditional ceramics. This “second (technological) life” of clays into fields of emerging interest is mainly due to clays’ peculiar properties, in particular their ability to exchange (capture) ions, their layered structure, surface area and reactivity, and their biocompatibility. Since the maximization of clay performances/exploitations passes through the comprehension of the mechanisms involved, this review aims at providing a useful text that analyzes the main goals reached by clays in different fields coupled with the analysis of the structure-property correlations. After providing an introduction mainly focused on the economic analysis of clays global trading, clays are classified basing on their structural/chemical composition. The main relevant physicochemical properties are discussed (particular attention has been dedicated to the influence of interlayer composition on clay proper-ties). Lastly, a deep analysis of the main relevant nonconventional applications of clays is presented. Several case studies describing the use of clays in biomedicine, environmental remediation, membrane technology, additive manufacturing, and sol-gel processes are presented, and results critically discussed.

Magnetically driven nanosponges with potential application as targeted drug delivery systems were prepared via the addition of magnetite nanoparticles to the synthesis of cyclodextrin and maltodextrin polymers crosslinked with 1,1′-carbonyldiimidazole. The magnetic nanoparticles were obtained separately via a coprecipitation mechanism involving inorganic iron salts in an alkaline environment. Four composite nanosponges were prepared by varying the content of magnetic nanoparticles (5 wt% and 10 wt%) in the cyclodextrin-and maltodextrin-based polymer matrix. The magnetic nanosponges were then characterised by FTIR, TGA, XRD, FESEM, and HRTEM analysis. The magnetic properties of the nanosponges were investigated via magnetisation curves collected at RT. Finally, the magnetic nanosponges were loaded with doxorubicin and tested as a drug delivery system. The nanosponges exhibited a loading capacity of approximately 3 wt%. Doxorubicin was released by the loaded nanosponges with sustained kinetics over a prolonged period of time.

The occurrence of uncontrolled electrostatic discharge (ESD) is among the major causes of damage in unprotected electronic components during industrial processes. To counteract this undesired phenomenon, ESD composites showing static-dissipative and antistatic responses are developed. In particular, static-dissipative materials are able to slow down the flow of electric charges, whereas antistatic materials directly suppress the initial charges induced by undesired charging by properly dispersing conductive fillers within an insulant matrix and thus forming a conductive filler network. In this context, the purpose of this review is to provide a useful resume of the main fundamentals of the technology necessary for facing electrostatic charging. The formation mechanisms of electrostatic charges at the material surface were described, providing a classification of ESD composites and useful characterization methods. Furthermore, we reported a deep analysis of the role of conductive fillers in the formation of filler networks to allow electric charge movements, along with an overview of the different classes of inorganic conductive fillers exploitable in ESD composites, evidencing pros/cons and criticalities of each category of inorganic fillers.

The continuous growing demand of fresh water to fulfil agricultural, industrial, and domestic needs of the global population points out the technological importance of performing smart and efficient wastewater remediation processes. One of the major problems related to water quality is represented by the impact due to emerging pollutants (EPs), a wide class of anthropic chemicals recently recognized (but poorly regulated), hardly removable by traditional treatments.[1] Hence, innovative heterogeneous processes based on the application of hybrid inorganic-organic magnet-responsive nanomaterials (MRNs, e.g., magnetic iron oxides) are receiving great attention as interesting alternative technologies exploitable in light-enhanced advanced oxidation processes (AOPs), and in more traditional sorption routes.[2] In this study, MRNs are functionalized by means of two different bio-based macromolecules, namely: BBS (i.e., humic-like substances isolated from green compost derived from agricultural biowaste), and chitosan (i.e., an amino-polysaccharide derived from shellfish industry biowaste). Both these organic macromolecules are in line with the “Waste Cleaning Waste” approach, very appealing from the green chemistry viewpoint.[3] Eventually, it has been investigated the possibility of converting such organic fractions into carbonaceous phases via pyrolysis, still maintaining the magnetic properties of the inorganic component. Hybrids MRNs are physicochemical, magnetic, and morphological characterized. Finally, in view of showing the potentiality of these hybrid systems, several case studies are discussed, in details: i) Testing BBS-iron oxide systems against caffeine (taken as model EPs) via light-enhanced AOPs at circumneutral conditions.[1] ii) Testing chitosan-derived carbonaceous-iron oxide systems against anthracene and naphthalene via sorption mechanism.[4] iii) Testing all hybrid systems against As(III) and As(V) via sorption mechanism.[5] Results indicate that thes

This work reports on the light-induced heterogeneous photodegradation of four micro-contaminants (MCs): Carbamazepine (C), Flumequine (F), Ibuprofen (I), and Sulfamethoxazole (S), using two different heterogeneous advanced oxidation processes. The first one is the semiconductor photocatalysis, run in the presence of the suspension of a home prepared TiO 2 (TiO 2 HP); the second one is an heterogeneous photo-Fenton process run in the presence of a hybrid magnetic nanomaterial (MB3) with an iron oxides core and an organic shell made of bio-based substances (BBS) isolated from urban biowaste. The two materials work upon two different mechanisms and were already tested (and the action mechanism hypothesized) at the lab scale under model conditions: TiO 2 acts as photocatalyst through the photo-generation of hole/electron pairs able to give rise to oxidation and reduction reactions, whereas hybrid magnetic nanomaterial acts in the presence of H 2 O 2 by a photo-Fenton like mechanism. The results evidenced the better performances of TiO 2 HP (also better than the well-known reference TiO 2 P25). Preliminary photodegradation experiments carried out in a pilot plant under natural solar radiation confirmed the good results obtained with TiO 2 HP. Moreover, in the adopted experimental conditions, the Fe(II) leached from MB3 can be considered as responsible of the MCs degradation through a homogeneous photo-Fenton reaction, where MB3 act as iron reservoir.

The past 3 decades of thorough scientific scrutiny of carbon nanotubes (CNTs) revealed that, in spite of their remarkable properties, some technological applications are adversely affected by certain difficulties in handling the CNTs, along with their tendencies, arising out of their graphitic structure, to form agglomerates and exhibit limited interaction with other materials. These issues play a crucial role when CNTs are applied as nanofillers inside matrices, in particular polar ones. In this case, unless several preliminary steps are taken, an efficient and uniform dispersion of the CNTs becomes impossible, thus the nanocomposite cannot exhibit the expected final properties. Unfortunately, a universal procedure does not exist since the problem of the dispersion of CNTs is very complex, and its solution requires an advanced understanding of the properties of the CNTs (e.g. whether the CNTs are single- or multiwalled, size, length, lattice defects etc.) as well as of the matrices used. This review aims to help the reader to select the appropriate dispersion procedure by acquiring fundamental knowledge regarding: (1) the synthesis and properties of pristine CNTs; (2) methods of chemical functionalization and properties of functionalized CNTs; and (3) methodologies for the mechanical dispersion of CNTs. A brief overview regarding chemo-physical characterization techniques is also given to enable a better evaluation of the properties of the CNTs, both before and after functionalization.