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Inorganic small particles stemming from mineral extraction (i.e. mining waste) could be used as additive for road paving applications to improve bitumen mechanical properties. Such an approach is expected to increase bitumen life-cycle cutting costs connected to their preparation and to reduce environmental issues. Experiment: Bitumens containing various amounts (up to 10% w/w) of filler made of mining tailings fine powder were characterized by means of oscillatory rheometry focusing on the effect of the filler content, temperature and filler milling time.(i) Superior resistance to stress, rutting, and fatigue were shown by the filler-containing mixtures. In addition, higher durability was observed for the filler concentration of 10% w/w. These effects were interpreted on the grounds of the physico-chemical interactions between the bitumen and the inorganic filler suggesting important utilizations. (ii) The present research points towards a circular economy path. Particularly, this study demonstrates how an abundant and potentially harmful waste can be converted into a high value-added component for road paving. Furthermore, increased durability of bitumen is beneficial in both economic and environmental terms.

Refuse-Derived Fuels (RDFs) are segregated forms of wastes obtained by a combined mechanical–biological processing of municipal solid wastes (MSWs). The narrower characteristics, e.g., high calorific value (18–24 MJ/kg), low moisture content (3–6%) and high volatile (77–84%) and carbon (47–56%) contents, make RDFs more suitable than MSWs for thermochemical valorization purposes. As a matter of fact, EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and the circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, compared to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutant emissions and the production of value-added products as chemical platforms or fuels. Despite the growing interest towards RDFs as feedstock, the literature on the thermochemical treatment of RDFs under pyrolysis and gasification conditions still appears to be limited. In this work, results on pyrolysis and gasification tests on a real RDF are reported and coupled with a detailed characterization of the gaseous, condensable and solid products. Pyrolysis tests have been performed in a tubular reactor up to three different final temperatures (550, 650 and 750 °C) while an air gasification test at 850 °C has been performed in a fluidized bed reactor using sand as the bed material. The results of the two thermochemical processes are analyzed in terms of yield, characteristics and quality of the products to highlight how the two thermochemical conversion processes can be used to accomplish waste-to-materials and waste-to-energy targets. The RDF gasification process leads to the production of a syngas with a H2/CO ratio of 0.51 and a tar concentration of 3.15 g/m3.

A gold nanoparticles transparent electrode was realized by chemical reduction. This work aims to compare the transparent gold nanoparticles electrode with a more commonly utilized gold-film-coated electrode in order to investigate its potential use as counter-electrode (CE) in dye-sensitized solar cells (DSSCs). A series of DSSC devices, utilizing I−/I3− and Co(III)/(II) polypyridine redox mediators [Co(dtb)3]3+/2+; dtb = 4,4′ditert-butyl-2,2′-bipyridine)], were evaluated. The investigation focused firstly on the structural characterization of the deposited gold layers and then on the electrochemical study. The novelty of the work is the realization of a gold nanoparticles CE that reached 80% of average visible transmittance. We finally examined the performance of the transparent gold nanoparticles CE in DSSC devices. A maximum power conversion efficiency (PCE) of 4.56% was obtained with a commercial I−/I3−-based electrolyte, while a maximum 3.1% of PCE was obtained with the homemade Co-based electrolyte.

Bitumens are composite systems extensively used in road pavements. Due to their complex nature, a rational understanding of the relationships between composition, structure and performances of these materials is still far from being achieved, so research attempting to shed more light in this field is required. Here, we exploit Wide Angle X-ray Scattering (WAXS) as a technique of choice to shed light on the bitumen structure at different length scales. Diagnostic fingerprints, characterizing the WAXS profile, are correlated to specific Bragg distances which can be reasonably attributed to the molecular and supramolecular aggregation taking place at various levels of complexity leading to the formation of hierarchical structures. Due to the inherent instability of these materials some indications are given to obtain reliable structural data.

Amphiphiles play a pivotal role in the area of self-assembled structures and interesting additional features can be obtained if metal ions are involved. In this ambit, the development of smart materials benefits from the availability of stimuli-responsive supramolecular amphiphile assemblies where the disassembly back-processes has an inherently basic role providing reversible switching particularly useful in novel approaches and applications. In this tutorial review the basic concepts on self-assembly of traditional and novel amphiphilic molecules with metals are summarized and the more recent concepts of supramolecular assembly are presented. The aim of this contribution is to furnish to the reader a panoramic view of this exciting problematic clarifying what is meant with the concept of complexity and how the rich world of amphiphilic molecules is employed with metals for obtaining complex nanostructure-based systems with novel characteristics for applications in nanotechnology.

The fabrication of enzyme-based biosensors has received much attention for their selectivity and sensitivity. In particular, laccase-based biosensors have attracted a lot of interest for their capacity to detect highly toxic molecules in the environment, becoming essential tools in the fields of white biotechnology and green chemistry. The manufacturing of a new, metal-free, laccase-based biosensor with unprecedented reuse and storage capabilities has been achieved in this work through the application of the electrospray deposition (ESD) methodology as the enzyme immobilization technique. Electrospray ionization (ESI) has been used for ambient soft-landing of laccase enzymes on a carbon substrate, employing sustainable chemistry. This study shows how the ESD technique can be successfully exploited for the fabrication of a new promising environment-friendly electrochemical amperometric laccase-based biosensor, with storage capability up to two months without any particular care and reuse performance up to 63 measurements on the same electrode just prepared and 20 measurements on the one-year-old electrode subjected to redeposition. The laccase-based biosensor has been tested for catechol detection in the linear range 2-100 μM, with a limit of detection of 1.7 μM, without interference from chrome, cadmium, arsenic, and zinc and without any memory effects.

From the nano-world to solar systems length-scales span over several orders of magnitude. In young student it is therefore hard to fully understand the relative proportions among different objects even belonging to the same level of complexity. Resizing to human-related distances is an effective way to understand the relative distances in astronomic scales or the amount of information contained in a single cell. In general, the use of imagination is essential in educational research as well as the use of different skills in interdisciplinary works. Some appealing example will be given and the result of a pilot learning by doing teaching pathway involving hundreds of young students will be presented. Clues will give indications for future directions in educational research.

Bitumen aging occurs through volatilization, oxidation and supramolecular assembly variations involving drastic changes in the structure of the material. Due to the ageing process of bitumen and its corresponding increase in viscosity, the stiffness of asphalt pavement is increased during its lifetime. Chemically, the relative content between asphaltenes and maltenes in the bitumen shifts towards a lower maltene fraction. Therefore, addition of high amounts of Reclaimed Asphalt Pavement (RAP) in asphalt mixtures may negatively affect the quality and performance of the final mix design. Rejuvenating agents can assist in this process by decreasing the aged bitumen's viscosity and restoring its original properties. An efficient rejuvenating agent favors there organization of the colloidal structure of the oxidized bitumen, thus recreating a supramolecular structure similar to fresh bitumen. Then, novel experimental approaches are needed to evaluate the efficiency of rejuvenators as well as the effect such additives have on aged bitumen properties. To achieve the aforementioned purpose, two advanced experimental approaches able to provide detailed information on bitumen microstructure are examined here. The essential concepts underlying the scattering and NMR techniques will be reviewed and the results of some recent applications of these methods in the evaluation of the effectiveness of the RAP rejuvenation will be synthetically illustrated.

The photochromic compound 2,6-bis(2-hydroxybenzilidene)cyclohexanone (PC) has been dissolved in some selected liquid amphiphiles: dibutyl, tributyl, bis-2-ethylhexyl, tris-2-ethylhexyl phosphate and bis-2-ethylhexyl amine. The aim was to explore its photophysical properties when embedded in the novel chemical environment provided by the amphiphilic solvents. UV-Vis spectra revealed different features depending on the solvent thus highlighting specific solvent-solute interactions and different chemical environments. All the alkylphosphate-based systems were found to be unstable; slow (days) changes in the absorption features due to the slow change in populations of the various species present in solution. Interestingly, the dissolution of PC into bis-2-ethylhexyl amine leads to stable solutions most probably due to the basic character of the solvent stabilising as major specie chalcone forms. Fluorescence spectra suggested the equilibrium between two species with different absorption and fluorescence properties.

Ionic liquids (ILs) are liquid materials at room temperature with an ionic intrinsic nature. The electrostatic interactions therefore play a pivotal role in dictating their inner structure, which is then expected to be far from the traditional pattern of classical simple liquids. Therefore, the strength of such interactions and their long-range effects are responsible for the ionic liquid high viscosity, a fact that itself suggests their possible use as lubricants. More interestingly, the possibility to establish a wide scenario of possible interactions with solid surfaces constitutes a specific added value in this use. In this framework, the ionic liquid complex molecular structure and the huge variety of possible interactions cause a complex aggregation pattern which can depend on the presence of the solid surface itself. Although there is plenty of literature focusing on the lubricant properties of ionic liquids and their applications, the aim of this contribution is, instead, to furnish to the reader a panoramic view of this exciting problematic, commenting on interesting and speculative aspects which are sometimes neglected in standard works and trying to furnish an enriched vision of the topic. The present work constitutes an easy-to-read critical point of view which tries to interact with the imagination of readers, hopefully leading to the discovery of novel aspects and interconnections and ultimately stimulating new ideas and research.

The guest editors for this special issue are pleased to welcome contributions from researchers studying smart nanostructured materials developed from molecular self-assembly processes and their advanced applications.

Owing to the amphiphilic nature of their constituent molecules, binary mixtures of pure liquid surfactants are usually characterized by enhanced nano-segregation and thus can exhibit interesting transport properties and complex macroscopic behavior. In this ambit it was recently shown by Turco Liveri et al. (J. Mol. Liq. 263 (2018) 274–281) at room temperature that mixtures of short aliphatic chains compounds, such as dibutyl phosphate (DBP) and n-propylamine (PA) liquids, due to their ability to allow for phosphate-to-amine proton transfer, display ionic liquid–like behavior with composition-dependent enhanced conductivity, viscosity, and magnetically-induced birefringence. To understand the molecular mechanisms at the basis of this behavior, in the present study a combination of nuclear magnetic resonance (NMR) and dielectric spectroscopy investigations has been carried out for the same materials for different amine molar ratios. It was found that at certain compositions all studied dynamical processes (conformational changes, local hopping of “free” protons among neighboring polar headgroups, long-range charge migration) exhibit significant deviations from ideal mixing behavior. The microscopic origin of these deviations is discussed.

Herein we describe the design and synthesis of novel artificial peptides mimicking the plastoquinone binding niche of the D1 protein from the green photosynthetic alga Chlamydomonas reinhardtii, also able to bind herbicides. In particular, molecular dynamics (MD) simulations were performed to model in silico the behaviour of three peptides, D1Pep70-H, D1Pep70-S264K and D1Pep70-S268C, as genetic variants with different affinity towards the photosynthetic herbicide atrazine. Then the photosynthetic peptides were functionalised with quantum dots for the development of a hybrid optosensor for the detection of atrazine, one of the most employed herbicides for weed control in agriculture as well as considered as a putative endocrine disruptor case study. The excellent agreement between computational and experimental results self consistently shows resistance or super-sensitivity toward the atrazine target, with detection limits in the ?g/L concentration range, meeting the requirements of E.U. legislation.

This paper considers the effect of aging processes on viscoelastic characteristics of vacuum residue oxidation products modified with crumb rubber. Viscoelastic properties were compared to original bitumen raw material-vacuum residue and vacuum residue oxidation products during short-term and long-term aging. The complex shear modulus of the vacuum residue and its oxidation products decreased with an increase in temperature. Short-term aging resulted in increased shear modulus for all samples.The vacuum residue oxidation product modified with crumb rubber had the maximum values of the rutting parameter and fatigue parameter. There was an expansion of the temperature range of plasticity: for the vacuum residue oxidation product with crumb rubber, its value was 67.2 °C. The curves of the black diagram of the modified vacuum residue oxidation product are shifted towards smaller phase angles with the increase in the shear modulus, which indicates the increase in the stiffness and elasticity of the rubber bitumen binders. The vacuum residue oxidation product modified with crumb rubber corresponded to the rubber bitumen binder of the grade RBB 60/90, according to its physical and mechanical indicators.

Urban waste management is a hard task: more than 30% of the world’s total production of Municipal Solid Wastes (MSW) is not adequately handled, with landfilling remaining as a common practice. Another source of wastes is the road pavement industry: with a service life of about 10–15 years, asphalts become stiff, susceptible to cracks, and therefore no longer adapted for road paving, so they become wastes. To simultaneously solve these problems, a circular economy-based approach is proposed by the ReScA project, suggesting the use of pyrolysis to treat MSW (or its fractions as Refuse Derived Fuels, RDFs), whose residues (oil and char) can be used as added-value ingredients for the asphalt cycle. Char can be used to prepare better performing and durable asphalts, and oil can be used to regenerate exhaust asphalts, avoiding their landfilling. The proposed approach provides a different and more useful pathway in the end-of-waste (EoW) cycle of urban wastes. This proof of concept is suggested by the following two observations: (i) char is made up by carbonaceous particles highly compatible with the organic nature of bitumens, so its addition can reinforce the overall bitumen structure, increasing its mechanical properties and slowing down the molecular kinetics of its aging process; (ii) oil is rich in hydrocarbons, so it can enrich the poor fraction of the maltene phase in exhaust asphalts. These hypotheses have been proved by testing the residues derived from the pyrolysis of RDFs for the improvement of mechanical characteristics of a representative bitumen sample and its regeneration after aging. The proposed approach is suggested by the physico-chemical study of the materials involved, and aims to show how the chemical knowledge of complex systems, like bituminous materials, can help in solving environmental issues. We hope that this approach will be considered as a model method for the future.

For asphalt concrete preparation in laboratory mix-design operations, bitumens are usually mixed with micrometer-sized particles (filler), sand and centimeter-sized crushed stones in a gyratory press at a temperature of about 140&ndash, 155 &deg, C depending on the bitumen viscosity, until adequate homogenization and compaction take place (air voids optimum). This requires energy consumption. To minimize it, the process needs to be optimized and is usually made empirically. The aim of this manuscript is to gain a comprehension of the physico-chemical mechanisms involved in the process by exploring: (i) the rheological properties (viscosity, activation energy) of a neat and RTFOT-aged bitumen, in presence and in absence of a filler, (ii) the volumetric and resistance behavior under the compaction in a standard Gyratory Compactor (GC) of their blends with aggregates and (iii) the mechanical properties (Indirect Tensile Strength, compression and tensile deformation) of the final products. Correlations between activation energy and pre-exponential factor of the viscosity on a side, and between viscosity, workability and final mechanical properties on the other side allowed to provide a rational interpretation of the physico-chemical processes involved in the framework of the physics of complex fluids. The scientific clues will be of help in optimizing the workability in asphalt concretes productions with obvious repercussions in terms of energy savings, useful for economic and environmental issues.

Scattering techniques represent non-invasive experimental approaches and powerful tools for the investigation of structure and conformation of biomaterial systems in a wide range of distances, ranging from the nanometric to micrometric scale. More specifically, small-angle X-rays and neutron scattering and light scattering techniques represent well-established experimental techniques for the investigation of the structural properties of biomaterials and, through the use of suitable models, they allow to study and mimic various biological systems under physiologically relevant conditions. They provide the ensemble averaged (and then statistically relevant) information under in situ and operando conditions, and represent useful tools complementary to the various traditional imaging techniques that, on the contrary, reveal more local structural information. Together with the classical structure characterization approaches, we introduce the basic concepts that make it possible to examine inter-particles interactions, and to study the growth processes and conformational changes in nanostructures, which have become increasingly relevant for an accurate understanding and prediction of various mechanisms in the fields of biotechnology and nanotechnology. The upgrade of the various scattering techniques, such as the contrast variation or time resolved experiments, offers unique opportunities to study the nano- and mesoscopic structure and their evolution with time in a way not accessible by other techniques. For this reason, highly performant instruments are installed at most of the facility research centers worldwide. These new insights allow to largely ameliorate the control of (chemico-physical and biologic) processes of complex (bio-)materials at the molecular length scales, and open a full potential for the development and engineering of a variety of nano-scale biomaterials for advanced applications.

Asphalt concretes are materials used worldwide. It is well-known that in such materials the minor component, the bitumen, plays the most important role since it binds the high fraction (>95%) of inorganic macrometer-sized particles ensuring a coherent material fit for uses in road pavement. Additives can be used to increase the overall rheological properties, with high benefits in terms of resistance to mechanical stress and to ageing. Among these, nanoparticles have recently been considered as very effective additives in increasing the overall performance, increasing the viscosity, the rutting parameter and the recovery from deformation. However, they are expensive, so a delicate equilibrium between costs and benefits must be found for large-scale uses. In this framework, we furnish our critical analysis of the state-of-the art technologies used for improving the bitumen performances by means of nanoparticles with an eye to eventual added-values (like anti-oxidant effect, antistripping properties, or UV radiation screening which avoids radiation-induced ageing…). We will critically consider the costs involved in their use and we will give our opinion about vanguard techniques which can be fit for the analysis of nanoparticles-containing bitumens and asphalts. Interesting perspectives will be also given for future research and applications.

In this paper, we survey recent advances in the self-assembly processes of novel functional platforms for nanomaterials and biomaterials applications. We provide an organized overview, by analyzing the main factors that influence the formation of organic nanostructured systems, while putting into evidence the main challenges, limitations and emerging approaches in the various fields of nanotechology and biotechnology. We outline how the building blocks properties, the mutual and cooperative interactions, as well as the initial spatial configuration (and environment conditions) play a fundamental role in the construction of efficient nanostructured materials with desired functional properties. The insertion of functional endgroups (such as polymers, peptides or DNA) within the nanostructured units has enormously increased the complexity of morphologies and functions that can be designed in the fabrication of bio-inspired materials capable of mimicking biological activity. However, unwanted or uncontrollable effects originating from unexpected thermodynamic perturbations or complex cooperative interactions interfere at the molecular level with the designed assembly process. Correction and harmonization of unwanted processes is one of the major challenges of the next decades and requires a deeper knowledge and understanding of the key factors that drive the formation of nanomaterials. Self-assembly of nanomaterials still remains a central topic of current research located at the interface between material science and engineering, biotechnology and nanomedicine, and it will continue to stimulate the renewed interest of biologist, physicists and materials engineers by combining the principles of molecular self-assembly with the concept of supramolecular chemistry.

Increasing awareness of environmental concerns has strongly pushed the scientific community towards the search for new solutions for efficient removal of oils and organic solvents from water. Here, we report the preparation of multifunctional TiO2-coated melamine-formaldehyde (MF) sponges as absorbent material for oils and organic solvents in water. TiO2-coated MF sponges were fabricated through an environmentally friendly approach, consisting in a simple immersion of the sponge into an oleic acid-capped TiO2 nanoparticles dispersion. The adhesion of TiOle coating to the sponge was then improved by the deposition of a low surface energy diamond-like carbon (DLC) thin layer. Our results highlighted that the modified MF sponges possess superhydrophobic and oleophilic behaviour, inertness to corrosive environment, good durability and reusability. Furthermore, the superhydrophobic DLC/TiO2@sponges showed (1) novel self-cleaning properties towards an absorbed commercial organic dye (IR-270BKA, chosen as representative) under visible light irradiation and (2) enhanced flame-retardant behaviour respect to the pristine MF sponge. These findings point out an important added value of DLC/TiOle@sponges making them promising candidates for wastewater treatments.

Asphalt concretes are biphasic systems, with a predominant phase (c.a. 93-96% w/w) made by the macro-meter sized inorganic aggregates hold together by small amounts of a viscoelastic binding bitumen (c.a. 5%). Even if the bitumen is in minor amount, it plays an important role dictating all the desired properties: rheological performances, resistance to aging etc. What happens if nanoparticles are used as additive in such materials? They usually confer enhanced resistance under mechanical stress and give sometimes interesting added-values properties so, despite the high costs of their production, nanoparticles are interesting materials which are being monitored for large scales applications. This work introduces the reader to the properties of nanoparticles in an easy to review their use in bitumen and asphalt preparation. Silica, ceramic, clay, other oxides and inorganic nanoparticles are presented and critically discussed in the framework of their use in bitumen and asphalt preparation for various scopes. Organic and functionalized nanoparticles are likewise discussed. Perspectives and cost analysis are also given for a more complete view of the problematic, hoping this could help researchers in their piloted design of material for road pavements with ever-increasing performances.

This paper reports the analysis of the intramolecular OH stretching band obtained by Fourier Transform Infrared (FTIR) spectroscopy measurements. In order to characterize the effect of montmorillonite on the properties of Bovine Serum Albumin (BSA) the two-state model is adopted for the analysis of the OH stretching band. We assume that the OH stretching can be divided into two different states of inter-molecular bonding. The results of this experimental work confirm that the montmorillonite leads to a stabilization of the BSA structure. Also, the analysis of the spectra temperature dependence shows a montmorillonite-induced higher thermal stability of the BSA in respect to pristine BSA. Thus, this paper allows to highlight the importance of montmorillonite as thermal bio-protector: this is also evidenced by the theory widely discussed in the following introduction regarding the birth of the first life forms on earth in montmorillonite clay, in which the protective role of the montmorillonite interlayer space is also highlighted. A FTIR analysis was carried out to investigate the interaction of montmorillonite with BSA. Two different approaches, i.e. Spectral Distance and Wavelet analyses, constitute two effective and innovative approaches for the characterization of the thermal properties of pristine BSA and of BSA in the presence of montmorillonite. The results allowed us to consider as BSA in the presence of montmorillonite has a lower spectral sensitivity when the temperature changes and, therefore, the role of montmorillonite as a thermal bio-protector is motivated.

Enzymes immobilisation represents a critical issue in the design of biosensors to achieve standardization as well as suitable analytical performances in terms of sensitivity, selectivity, and stability. In this work electrospray deposition (ESD) has been exploited as a novel technique for the immobilisation of laccase enzyme on carbon black modified screen-printed electrodes. The aim is to fabricate an amperometric biosensor for phenolic compound detection. The electrodes produced by ESD have been analysed by scanning electron microscopy and characterised electrochemically to prove that this immobilisation technique is suited to manufacture high performance biosensors. The results show that the laccase enzyme maintains its activity after undergoing the electrospray ionisation process and deposition and the fabricated biosensor has improved performances in terms of storage (up to 3 months at room temperature) and working (up to 25 measurements on the same electrode) stability. The laccase-based biosensor has been tested for phenolic compound detection, with catechol as target analyte, in the linear range 2.5–50 μM, with 2.0 μM limit of detection, without interference from lead, cadmium, atrazine, and paraoxon, and without matrix effect in drinking, surface, and wastewater.

The investigation of the structural features in biological membranes represents a central topic in many aspects of biological science. It involves the study of the collective behavior of a great number of interacting macromolecules, while the study of the structure-function relationship require the observation and calculation of a large number of key factors. The self-assembly processes involved in biomembranes represent the cornerstone of the biological systems functioning, due to the special role of the complex macromolecular assemblies containing lipids, proteins, carbohydrates, nucleic acids, and other active components. In this article, we describe the main techniques and approaches employed for the investigation of biological membranes, which are characterized by a wide range of the space-time domains. The future challenge in this research field must provide the integration of the different research models and approaches into a common background based on multi- and interdisciplinary method that combine the expertise coming from the different disciplines.

The asphalt industry’s incentive to reduce greenhouse gas emissions has increased since the 1990s due to growing concerns on environmental issues such as global warming and carbon footprint. This has stimulated the introduction of Warm Mix Asphalt (WMA) and its technologies which serve the purpose of reducing greenhouse gas emissions by reducing the mixing and compaction temperatures of asphalt mix. WMA gained popularity due to the environmental benefit it offers without compromising the properties, performance and quality of the asphalt mix. WMA is produced at significantly lower temperatures (slightly above 100 °C) and thus results in less energy consumption, fewer emissions, reduced ageing, lower mixing and compaction temperatures, cool weather paving and better workability of the mix. The latter of these benefits is attributed to the incorporation of additives into WMA. These additives can also confer even better performance of WMA in comparison to conventional Hot Mix Asphalt (HMA) methods. Even though there are recommended dosages of several WMA additives, there is no general standardized mixture design procedure and this makes it challenging to characterize the mechanism(s) of action of these additives in the warm mix. The effects of the addition of additives into WMA are known to a reasonable extent but not so much is known about the underlying interactions and phenomena which bring about the mechanism(s) by which these additives confer beneficial features into the warm mix. Additives in a certain way are being used to bridge the gap and minimize or even nullify the effect of the mixing temperature deficit involved in WMA processes while improving the general properties of the mix. This review presents WMA technologies such as wax, chemical additives and foaming processes and the mechanisms by which they function to confer desired characteristics and improve the durability of the mix. Hybrid techniques are also briefly mentioned in this paper in addition to a detailed description of the specific modes of action of popular WMA technologies such as Sasobit, Evotherm and Advera. This paper highlights the environmental and technical advantages of WMA over the conventional HMA methods and also comprehensively analyzes the mechanism(s) of action of additives in conferring desirable characteristics on WMA, which ultimately improves its durability.

The involvement of metal ions within the self-assembly spontaneously occurring in surfactant-based systems gives additional and interesting features. The electronic states of the metal, together with the bonds that can be established with the organic amphiphilic counterpart, are the factors triggering new photophysical properties. Moreover, the availability of stimuli-responsive supramolecular amphiphile assemblies, able to disassemble in a back-process, provides reversible switching particularly useful in novel approaches and applications giving rise to truly smart materials. In particular, small amphiphiles with an inner distribution, within their molecular architecture, of various polar and apolar functional groups, can give a wide variety of interactions and therefore enriched self-assemblies. If it is joined with the opportune presence and localization of noble metals, whose chemical and photophysical properties are undiscussed, then very interesting materials can be obtained. In this minireview, the basic concepts on self-assembly of small amphiphilic molecules with noble metals are shown with particular reference to the photophysical properties aiming at furnishing to the reader a panoramic view of these exciting problematics. In this respect, the following will be shown: (i) the principles of self-assembly of amphiphiles that involve noble metals, (ii) examples of amphiphiles and amphiphile-noble metal systems as representatives of systems with enhanced photophysical properties, and (iii) final comments and perspectives with some examples of modern applications.

Tuning the rheological properties of bitumens is extremely important for applicative purposes. This can be achieved by the use of chemical additives tuning the asphaltene-asphaltene and asphaltene-maltene interactions. We propose the use of an epoxy-resin to give more rigid and thermally stable bitumens on the basis of its tendency to form polymeric networks which would bridge asphaltene clusters. Rheometry confirmed this hypothesis and showed that a load of epoxy-resin as low as 0.1% gives the highest rigidity. Atomic Force Microscopy highlighted the structural changes at the basis of the observed effects. The small amount of epoxy resin needed and its low-cost are elements deserving monitoring.

Alkyl phosphates are experiencing an ever increasing use due to the current arising of new applications. This implies their increasing presence in the environment so their stability and reactivity under high-energy photons, which are still unknown, need to be clarified. In this study, a mass spectrometric investigation of the ionization and fragmentation processes of four representative alkyl phosphates (dibutyl, tributyl, bis-2-ethylhexyl, and tris-2-ethylhexyl phosphate) induced by vacuum ultraviolet (VUV) radiation has been carried out. The experimental data show that fragmentation occurs through a stepwise cleavage of the bonds between the phosphate group and the alkyl chains leading to the formation of esters with a lower number of alkyl chains and the protonated orthophosphoric acid as ending product. Interestingly, the presence of charged species with mass-over-charge (m/z) values larger than the parent ion is also observed in dibutyl and bis-2-ethylhexyl phosphate, suggesting the existence of their dimers in the gas phase. This has been rationalized, with the aid of ab-initio DFT calculations, in terms of the capability of these molecules to form H-bonds. The photo-induced reactivity in the gas phase has been clarified, and its similarity with the natural bacterial degradation has been pointed out.

Owing to the amphiphilic nature of their constituent molecules, binary mixtures of pure liquid surfactants are usually characterized by enhanced nano-segregation and thus can exhibit interesting transport properties and complex macroscopic behavior. In this ambit it was recently shown by Turco Liveri et al. (2018) that mixtures of short aliphatic chains compounds at room temperature, such as dibutyl phosphate (DBP) and n-propylamine (PA) liquids, display ionic liquid–like behavior ascribed to phosphate-to-amine proton transfer. To gain a detailed molecular picture of the system structure and dynamics and to understand the molecular mechanisms at the basis of the observed behavior, in the present study a combination of ab initio Density Functional Theory (DFT) calculation and ab initio Molecular Dynamics (AIMD) simulation has been carried out on DBP + PA clusters. It was found that in these systems the proton transfer is a cooperative process boosted by the concerted interactions of more than one DBP-PA pair. Moreover, classical molecular dynamics (MD) simulations of large DBP + PA systems showed that, triggered by steric effects due to the alkyl chains of both components, these interactions are able to build an extended network of polar domains embedded in an apolar environment of alkyl chains.

Bitumen is a complex material used for road pavement throughout the world. During paving and pavement service life loss of more volatile compounds and oxidization takes place. Hence, asphaltene micelles become larger so that the fluidity of the system is reduced; the material becomes rigid, stiff and brittle so needing replacement. Once removed, it can be processed to restore its original properties and used for Reclaimed Asphalt Pavement (RAP). For such a process, additives called “rejuvenators” are used: they act on the chemical structure of aged bitumen to restore its physical properties to a state very similar to virgin bitumen. Alternatively, softening agents can be used to restore only the physical properties. An additive conferring regenerating characteristic on the asphalt mix increases the longevity of asphalt pavements due to the fact that it brings the bitumen back to its initial state; on the other hand, softening agents render the aged bitumen more workable but road pavements remain rigid and eventually break in the course of use. At the moment, methods that can distinguish a regenerating effect from a fluxing effect are not known. This study aims at evaluating the different effects of the additives on aged bitumen. For this purpose, we used a commercial additive (tritolyl poly phosphate, TPI) working as rejuvenator and a softening agent (soy oil) which is a well-known fluxing agent. The effects of the additives on aged bitumen have been investigated through Dynamic Shear Rheometer, Atomic Force Microscopy, Optical Microscopy and Infrared Spectroscopy.

Tarnishing is a process taking place in silver surface causing corrosion. This is due to the presence in the atmosphere, even in small amounts, of reactive species like water, sulphidric acid and carbonyl sulphide which can be physisorbed onto the silver surface thus reacting with it. We propose the use of alkylphosphates to protect the silver surface against corrosion: the polar head group should interact with the silver surface with the formation of a thin film of opportunely oriented surfactant molecules. This would shield the silver surface from the attack of reactive agents present in the atmosphere and from the adsorption of humidity water helped by the surfactant scarce hydrophilicity. The joint Raman and XPS experiments showed the protective action exerted by dibutylphosphate or bis (2-etylhexyl) phosphate according to the different sulphidizing conditions. Our discovery deserves to be tailored in cultural heritage where silver artefacts are generally precious and inimitable objects, but also in modern microelectronics where silver joints and conductors are used.

Magnetically-induced birefringence is usually low in molecular liquids owing to the low magnetic energy of molecules with respect to the thermal one. Despite this, it has been found that a mixture of dibutyl phosphate and propylamine at propylamine molar ratio (X) around 0.33 surprisingly gives an intense effect (∆n/&lambda, &asymp, &minus, 0.1 at 1 Tesla). In this paper the time- and intensity- response to the magnetic field of such mixture have been studied. It was found that the reaction to the magnetic field is unusually slow (from several minutes to hours) depending of the magnetic field intensity. On the basis of the data, the model of orientable dipoles dispersed in a matrix enables to interpret the magnetic field-induced self-assembly in terms of soft molecules-based nanostructures. The analogy with systems made of magnetically polarizable (solid or soft) particles dispersed in liquid carrier allows understanding, at the microscopic scale, the molecular origin and the supra-molecular dynamics involved in the observed behavior. The data present a novel phenomenon in liquid phase where the progressive building up/change of ordered and strongly interacting amphiphiles is driven by the magnetic field.

This review aims to explore the state of the knowledge and the state-of-the-art regarding bitumen rejuvenation. In particular, attention was paid to clear things up about the rejuvenator mechanism of action. Frequently, the terms rejuvenator and flux oil, or oil (i.e., softening agent) are used as if they were synonymous. According to our knowledge, these two terms refer to substances producing different modifications to the aged bitumen: they can decrease the viscosity (softening agents), or, in addition to this, restore the original microstructure (real rejuvenators). In order to deal with the argument in its entirety, the bitumen is investigated in terms of chemical structure and microstructural features. Proper investigating tools are, therefore, needed to distinguish the different mechanisms of action of the various types of bitumen, so attention is focused on recent research and the use of different investigation techniques to distinguish between various additives. Methods based on organic synthesis can also be used to prepare ad-hoc rejuvenating molecules with higher performances. The interplay of chemical interaction, structural changes and overall effect of the additive is then presented in terms of the modern concepts of complex systems, which furnishes valid arguments to suggest X-ray scattering and Nuclear Magnetic Resonance relaxometry experiments as vanguard and forefront tools to study bitumen. Far from being a standard review, this work represents a critical analysis of the state-of-the-art taking into account for the molecular basis at the origin of the observed behavior. Furnishing a novel viewpoint for the study of bitumen based on the concepts of the complex systems in physics, it constitutes a novel approach for the study of these systems.

Bitumens are composite materials whose complex organization hinders the rational understanding of their relationships between composition, structure and performances. So, research attempting to shed more light in this field is required. In this work Wide Angle X ray Scattering (WAXS) has been used to explore the influence of six opportunely chosen additives on the bitumen structure with the aim to ultimately correlate the findings with the bitumen performances. Diagnostic fingerprints have been observed in the WAXS profile: asphaltenes form stuck of about 18 A and constituted by about 6 asphaltene units on average. Such stucks are, in turn, organized at higher levels of complexity forming anisotropic aggregates of about 200 A × 28 A which, again, are assembled to form micrometer-size elongated aggregates characterized by the so-called bee-structure. The structural effects of the six opportunely chosen additives (Organosilane, Polyphosphoric, Phospholipids, Acetamidophenol, Oleic Acid, octadecylamine) have been pointed out and, corroborated by AFM images, have been correlated with the rheological behavior and justified at the microscopic level: additive with an apolar nature are preferentially located in the maltene phase weakening asphaltene inter-clusters interactions and softening the bitumen, whereas, on the contrary more polar additives act in opposite directions. Peculiar behavior have been unveiled in the case of amphiphilic additive due to the simultaneous presence, within their molecular architecture, of both polar and apolar moieties. The knowledge of the detailed effect of appropriately chosen additives on the nanoscopic and mesoscopic structure and their correlation with the rheological properties constitute the first step for opening the door to the piloted design of new bitumens with desired properties for ad-hoc uses.

We present a synopsis of 90 references on the last trends in electrochemical laccase-based biosensors and highlight how forefront technologies have prompted the development of smarter biosensors boosting their applications in agro-environmental and biomedical fields. This review updates a previous one published by Rodriguez-Delgado and co-workers in Trends in Analytical Chemistry 74 (2015) 21–45 and covers the research advances over the period between 2015 and 2019. In particular, a general overview on laccase structure and function is reported emphasizing its electrochemistry features as suitable bioreceptor for electrochemical devices. Then, we describe how crosscutting technologies like nanotechnology, material science, and immobilisation strategies can help to enhance the analytical performances of laccase-based biosensors.

The self-assembly process in a water solution of an amphiphilic polydimethylsiloxane-b-polyethyleneoxide (PDMS-PEO) diblock copolymer was investigated by means of small-angle X-ray scattering (SAXS) experiments in the concentration region below (and near) the critical micellar concentration (c.m.c. = 0.007 g cm(-3)). In the highly diluted region, at the copolymer concentration of c = 0.002 g cm(-3), the early stage of the self-assembly process was characterized by the formation of small (primary) micellar units (with a radius of R = 2.7 nm) with core-shell morphology, which coexisted with larger supramolecular aggregates of entangled micelles (with an average radius of R = 9.5 nm). The increase in the copolymer concentration (to c = 0.005 and c = 0.01 g cm(-3)) caused increase in the sizes of both the small micelles and supra-micellar aggregates. Interestingly, at the concentration of c = 0.005 g cm(-3), both the size and micelle aggregation number (N-agg) were found to increase on increasing the temperature in the range of 10

In recent years, the development of novel approaches for the formation of lipid nano-formulations for efficient transport of drug molecules in living systems offers a wide range of biotechnology applications. However, despite the remarkable progress in recent methodologies of synthesis that provide a wide variety of solutions concerning the liposome surface functionalization and grafting with synthetic targeting ligands, the action of most liposomes is associated with a number of unwanted side effects diminishing their efficient use in nanomedicine and biotechnology. The major limitation in the use of such versatile and smart drug delivery systems is connected with their limited colloidal stability arising from the interaction with the complex environment and multiform interactions established within the specific biological media. Herein, we review the main interactions involved in liposomes used in drug delivery processes. We also analyze relevant strategies that aim at offering possible perspectives for the development of next-generation of liposomes nanocarriers that are able to overcome the critical issues during their action in complex biological media.

Mixed Cu–Ag alloys with different compositions have been produced and subjected to an accelerated sulphidation process which causes the development of a mixed sulphide-rich corroded film on their surface. It was called tarnishing, that is, the formation of a blue-brownish patina when Cu–Ag alloys are exposed in a sulfur-containing atmosphere. The structures of the pristine alloys have been determined by the combined analytical techniques as scanning electron microscopy energy dispersive X-ray microanalysis and X-ray diffraction. The experimental conclusions confirmed the occurrence of micro phase separation with the formation of different dendritic domains of about 10 µm in width. The sulphidized samples were firstly investigated by optical microscopy and X-ray diffraction in order to verify the homogeneity of the patina and to identify the different AgCuS phases appearing on the alloy surfaces. It was observed that, despite the inherent micro-heterogeneity of the alloys, the sulphide layer was throughout uniform in composition at the micro-scale. The complex scenario of the relative stability of all the various mixed sulphides involved was then explored by micro-Raman spectroscopy (μ-RS), pointing out that the Cu-for-Ag substitution in the crystal lattice of the mixed Ag–Cu sulphides caused a monotonous blue shift of the vibrational wavenumbers in Raman spectra. This study has unveiled microscopic details of the tarnishing process, furnishing an innovative, cheap and non-destructive methodology based on μ-Raman spectroscopy for the evaluation of the silver-copper artefacts via the compositions of their corroded products. Copyright © 2016 John Wiley & Sons, Ltd.

Dibutyl phosphate (DBP)/bis(2-ethylhexyl) amine (BEEA) liquid mixtures can show optical birefringence when exposed to a magnetic field. It has been hypothesized that this is a consequence of self-segregation characterizing these systems giving formation of anisotropic local assemblies which are able to re-orient under magnetic field. In this work, an ab-initio Density Functional Theory computer modeling coupled with synchrotron X-Ray Scattering (XRS) experiments carried out at various BEEA molar ratio (X) and temperatures (10 ≤ T ≤ 60 °C) permitted to highlight the physical origin of this effect: a DBP-to-BEEA proton transfer with formation of an inherently anisotropic DBP-BEEA ion pair constituting the building block of highly structured ionic liquid nanodomains. At non-equimolar compositions (X ≠ 0.5) such ionic liquids domains are dispersed in the component in excess. At X > 0.5 the ionic liquids nanodomains are dispersed in excess of poorly structured BEEA, creating the ideal assumptions for the formation of a two-phase dispersed system, as confirmed by Guinier analysis in the small angle regime of the XRS spectra, explaining the system capability to become birefringent in reaction to external magnetic field. These information can be transferred to other amphiphiles-based mixtures for the piloted design of new magnetic field responsive materials with advanced applications.

Binary mixtures of liquid surfactants, owing to the amphiphilic nature of the molecules involved, can exhibit peculiar self-assembly. The amphiphilicity can be tuned by changing the length of the molecule alkyl chains and the nature of the polar head groups. If the surfactants are opportunely chosen (i.e. one basic and the other acidic) the resulting self-assembly can confer a lot of novel and interesting properties. This leads to smart materials and even to ionic liquids. This is an unprecedentedly easy way to prepare materials with desired properties. The strategy will be presented as well as some examples of recent developments

A modified one step and cost-effective chemical green route has been used to synthesize oleate-capped TiO2 anatase nanocrystals (NCs) doped with different amounts of europium, with high yields and without high-temperature post-calcination processes. Europium doping endowed TiO2 NCs with an intense red luminescence associated with the D-5(0) -> F-7(2) transition of the electronic structure of Eu3+ and was responsible for both the morphological change of the NCs structure (from nanorods to spherical nanoparticles) and the blue shift in the absorption edge respect to the undoped TiO2 NCs. Furthermore, photocatalytic experiments revealed that a low-content (0.5 mol%) Eu3+ doped TiO2 NCs showed the best ability as photocatalyst for the degradation of methylene blue (MB) under both UV and visible light irradiation, even if all the Eu3+ doped oleate-capped TiO2 NCs were more effective under visible light. Moreover, taking advantage of their photocatalytic activity, the 0.5% Eu3+ doped oleate-capped TiO2 photocatalysts has been employed on cotton fabrics. Our results highlighted that functionalization of cotton textile with Eu3+ doped oleate-capped TiO2 NCs imparted new functionalities, such as a high photocatalytic activity toward MB degradation under visible light. In addition, it determined also the change in the wetting behaviour of cotton that switches to a superhydrophobic nature. The obtained fabric also showed stable and robust superhydrophobicity against strong acid and alkaline environments. Multifunctional materials having simultaneously luminescence, superhydrophobicity and visible light photocatalysis are expected to be very useful in many technological applications. (C) 2017 Elsevier B.V. All rights reserved.

The Role of Imagination is pivotal in Managing the Complexity in Material Science

Binary mixtures of liquid surfactants, owing to the amphiphilic nature of the molecules involved, can exhibit nano-segregation and peculiar transport properties. The amphiphilicity, and consequently the resulting self-assembly, can be tuned by changing the length of the alkyl chains and the nature of the polar head group. So, in the present study, the structural and dynamic properties of dibutyl phosphate/propylamine liquid mixtures at various compositions have been investigated by Wide Angle X-ray Scattering (WAXS), FT-IR, rheometry and dielectric spectroscopy in order to study the intermolecular association taking place when alkylphosphates and alkylamines with a small apolar part are mixed together. It was found that a proton transfer from the dibutyl phosphate PO4H group to the propilamine NH2 one takes place, due to the acidic and basic nature of the two molecules involved. This triggers the formation of charged species and an intermolecular association typical of ionic liquid systems and causing an increase in viscosity of two orders of magnitude with respect to the two pure components. Effects due to the different amine isomers have been highlighted since the steric hindrance of the amine alkyl chain can significantly contribute to the molecular slippage thus affecting the overall mixture viscosity. Surprising dielectric properties have also been observed at a specific composition: a strikingly enhanced proton conductivity and a negative value of the dielectric constant in the MHz frequency range, as a result of the local self-assembly and the competition between the mechanism of jump of “free” protons among neighboring polar headgroups and the molecularly-assisted mechanism of charge transport. This work shows news potentialities of such systems as specialized solvent media and proton conducting water-free organic-based liquid systems and, from a more general prospect, the comprehension of the molecular mechanism involved in their transport properties is pivotal for the piloted design of smart materials for specific applications.