Polyvinyl alcohol is the most commercially water-soluble biodegradable polymer, and it is in use ... more Polyvinyl alcohol is the most commercially water-soluble biodegradable polymer, and it is in use for a wide range of applications. It shows good compatibility with most inorganic/organic fillers, and enhanced composites may be prepared without the need to introduce coupling agents and interfacial modifiers. The patented high amorphous polyvinyl alcohol (HAVOH), commercialized with the trade name G-Polymer, can be easily dispersed in water and melt processed. HAVOH is particularly suitable for extrusion and can be used as a matrix to disperse nanocomposites with different properties. In this work, the optimization of the synthesis and characterization of HAVOH/reduced graphene oxide (rGO) nanocomposite obtained by the solution blending process of HAVOH and Graphene Oxide (GO) water solutions and ‘in situ’ reduction of GO is studied. The produced nanocomposite presents a low percolation threshold (~1.7 wt%) and high electrical conductivity (up to 11 S/m) due to the uniform dispersion ...
this paper reports the experimental results of an on-going project running at lab-scale and aimed... more this paper reports the experimental results of an on-going project running at lab-scale and aimed at the valorization of roasted hazelnut cuticles through both chemical (i.e., solvent extraction) and thermochemical treatment (i.e., torrefaction) routes. In particular, the potential of using water as a green solvent for the extraction of bioactive compounds (i.e., substances of chemical-food-pharmaceutical interest, such as the polyphenols) contained in residues originated by industrial processing of hazelnuts has been investigated, applying the conventional laboratory Soxhlet extraction procedure. A subsequent valorization stage has been explored for the spent post-extraction residues versus the “as collected” ones; they lend themselves to become “renewable” solid fuels thanks to torrefaction, which is a “mild” thermochemical conversion process. The obtained results are first presented in terms of theoretical yields of the bioactive compounds of interest with respect to the original...
Tomato - From Cultivation to Processing Technology [Working Title]
In the last years, the European Commission has been funding numerous projects regarding the valor... more In the last years, the European Commission has been funding numerous projects regarding the valorization of food wastes. Tomato by-products received great attention especially in Spain, Italy, Greece, and Portugal due to high volumes and high concentration of valuable compounds. Among 40 funded projects about the management of tomato wastes in general, 14 projects are strictly connected to the valorization and exploitation of the tomato residues/by-products after processing and are of great interest for their scientific, technical, and economical outcomes. They received an overall budget of around 37 M€ over 35 years, involving 20 European and 4 non-European countries, with project coordinators located in Germany, the Netherlands, and Italy in most of the cases. This chapter delivers general information about these projects, assessing and reporting scientific and technical results. Moreover, the interconnection is highlighted among them by focusing on the contribution they gave to t...
Reduced graphene oxide supporting silver nanoparticles, obtained by an efficient, "green&quo... more Reduced graphene oxide supporting silver nanoparticles, obtained by an efficient, "green" and one step "top- down" solution route, was used for removal from water of chlordane, a known persistent organic pollutants. A two-step mechanism, involving chlordane degradation by Ag nanoparticles and subsequent adsorption of the degraded products: ether bis(2-chloro allyl), 1,10-dichlorodecane and octadecanoid acid were detected, on the reduced graphene oxide surface, leads to a complete removal of chlordane from water solution in only 11 minutes at room temperature.
In this work, a new natural hydrogel containing reduced graphene oxide (RGO) supporting silver (A... more In this work, a new natural hydrogel containing reduced graphene oxide (RGO) supporting silver (Ag) nanoparticles composite were successfully prepared and tested as catalyst for waste water treatment. The formed hydrogels contain a network structure of cross-linked nanosheets decorated with metal nanoparticles. The reported method is based on in situ co-reduction of GO and Ag acetate within the natural hydrogel matrix to form RGO-based composite gel, carried on with a 'green' process. The silver nanoparticles were homogeneously and uniformly dispersed on the surface of the RGO nanosheets. The hybrid acts as catalyst for the reduction of organic pollutants in an aqueous environment, while the natural hydrogels hinders the intrinsic aggregation of the nanofiller, due to the protection of the formed 3-D network, preserving the catalytic activity. Interestingly, the as-prepared catalytic composite matrix structure can be easily handled, e.g. for separation from an aqueous enviro...
The industrial processing of tomato leads to substantial amounts of residues, typically known as ... more The industrial processing of tomato leads to substantial amounts of residues, typically known as tomato pomace or by-products, which can represent as much as 10% by weight of fresh tomatoes. At present, these residues are either used as feedstock for animals or, in the worst case, disposed of in landfills. This represents a significant waste because tomato pomace contains high-value compounds like lycopene, a powerful antioxidant, cutin, which can be used as a starting material for biopolymers, and pectin, a gelling agent. This article presents an overview of technologies that valorize tomato by-products by recovering added-value compounds as well as generating fuel for energy production. These technologies include operations for extraction, separation, and exploitation of lycopene, cutin and pectin, as well as the processes for conversion of the solid residues to fuels. Data collected from the review has been used to develop a biorefinery scheme with the related mass flow balance, ...
Three-dimensional (3D) printing is often considered synonymous with additive manufacturing. Sever... more Three-dimensional (3D) printing is often considered synonymous with additive manufacturing. Several types of 3D printer are known where polymers are usually used. Stereolithography (SLA) employs a single beam laser to polymerize or crosslink a photopolymer resin. By drawing on the liquid photopolymer resin with a light beam, thin layers of polymer are stacked layer by layer. Elastomer based on polydimethysiloxanes (PDMS) are an important class of materials, because of properties such as chemical inertness, flexibility, and optical transparence. In addition, they have a very low surface tension (20.4 mN/m) and glass transition temperatures (146 K). it is possible to print a support material that holds the PDMS prepolymer in place until it can be cured by UV light using a photoactive cross-linking agent. It is possible to graft photoactive group on PDMS backbone and obtain a new UV curable polymer [1,2]. The aim of the presented work is to obtain photopolymers based on PDMS [3]. For t...
This contribution is a piece of work within a more comprehensive research program dedicated to a ... more This contribution is a piece of work within a more comprehensive research program dedicated to a thorough exploitation of industrial tomato by-products, which should be technically feasible, economically convenient and environmentally friendly. In this respect, the proposed paper focuses three aspects of newer and broader interest: lycopene extraction, cutin separation and compost production. The investigated case study refers to the tomato industry in the Campania region (IT). The lycopene extraction from peels is usually carried out by a solventor supercritical CO2-assisted operation; the separation of cutin is performed in two process steps: alkaline hydrolysis and acidification. The solid residual, after cutin separation, is proposed to be used as feedstock for composting, not alone, but mixed with other suitable biomass to adjust both the final moisture content and C/N ratio. To this end, two scenarios according to the “biorefinery cascade approach” were developed that differ i...
Graphene-based materials in different configuration have been subject of intense investigation an... more Graphene-based materials in different configuration have been subject of intense investigation and have proven excellent candidates as electrode material for supercapacitors [1]. Recently, researchers have been focused their attention on the exploitation of the reduced graphene oxide electrochemical properties [2]. Although reduced graphene oxide is light-weight, highly flexible and electrically conductive, the restacking between individual graphene sheets, dramatically lowers the large initial surface area leading to limited specific capacitance values. Metal oxides and conductive polymers have been used as spacers to avoid graphene restacking and improve performances. Although metals are provided with high electrical conductive and able to give pseudocapacitance, they are rarely studied in combination with graphene [3]. In this work, we demonstrated an efficient, “green” and one step “top-down” solution route for the preparation of silver nanoparticles decorated graphene (rGO_Ag) ...
The aim of this work is to model a more environmental-friendly production of biodiesel from tomat... more The aim of this work is to model a more environmental-friendly production of biodiesel from tomato seed oil to assess the feasibility of using an alternative catalyst. The AspenPlus® software is used to this end. Different cases are evaluated and compared, by changing the catalyst and by considering the additional production of high purity glycerol and potassium phosphate. Tomato seed oil obtained from tomato pomace coming from local industries, methanol and catalyst are considered as raw materials. Based on literature data, a methylesters yield formulation is developed and the catalytic transesterification reaction implemented in a simulated reactor, while methanol is recovered by distillation and recycled to the reactor. The necessary distillation towers are designed. All the mass and energy balances were set up for the whole process. The energy return of investment (EROI) was determined by considering the energy for harvesting and that for producing biodiesel. Results show that t...
The aim of this work is to model the extraction of pectin from tomato peels using different acids... more The aim of this work is to model the extraction of pectin from tomato peels using different acids that could be more environmentally friendly. The AspenPlus® software is used to this end. Several cases, such as considering different extracting acids, the recycle of water and washing solvent streams are evaluated and compared. Tomato peels seasonally generated by factories in a local district, were considered as raw materials, as well as methanol and catalyst. Based on literature data and using Excel® worksheet, the mass and energy balances were set up for the extraction reactor and, hence, a pectin extraction yields up to 25 % and 17 %, for two different scenarios, was determined, while the washing and purification stages were simulated and optimized in AspenPlus®. The distillation tower for solvent recover was designed. The economic potential of these cases was calculated by considering utilities cost, product and by-product sales, wastewater treatment as well as raw material costs...
Backside tungsten coating of copper foils allows for the chemical vapor deposition of exclusively... more Backside tungsten coating of copper foils allows for the chemical vapor deposition of exclusively single-layer graphene sheets.
Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by ... more Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by an easy and low-cost method of melt blending of preliminary grinded poly(lactic acid) (PLA) with nanosized carbon fillers used as powder. Morphological, structural and mechanical properties were investigated to reveal the influence of carbon nanofiller on the PLA–based composite. The dependence of tensile strength on nanocomposite loading was defined by a series of experiments over extruded filaments using a universal mechanical testing instrument. The applying the XRD technique disclosed that compounds crystallinity significantly changed upon addition of multi walled carbon nanotubes. We demonstrated that Raman spectroscopy can be used as a quick and unambiguous method to determine the homogeneity of the nanocomposites in terms of carbon filler dispersion in a polymer matrix.
Decoration with silver nanoparticles was obtained by coating graphene with a polydopamine layer, ... more Decoration with silver nanoparticles was obtained by coating graphene with a polydopamine layer, able to induce spontaneous metallic nanoparticles formation without any specific chemical interfacial modifier, neither using complex instrumentation. The choice of dopamine was inspired by the composition of adhesive proteins in mussels, related to their robust attach to solid surfaces. The synthesis procedure started from graphite and involved eco-friendly compounds, such as Vitamin C and glucose as reducing agent and water as reaction medium. Silver decorated graphene was inserted as secondary nanofiller in the formulation of a reference conductive adhesive based on epoxy resin and silver flakes. A wide characterization of the intermediate materials obtained along the step procedure for the adhesive preparation was carried out by several techniques. We have found that the presence of nanofiller yields, in addition to an improvement of the thermal conductivity (up to 7.6 W/m · K), a dr...
Polyvinyl alcohol is the most commercially water-soluble biodegradable polymer, and it is in use ... more Polyvinyl alcohol is the most commercially water-soluble biodegradable polymer, and it is in use for a wide range of applications. It shows good compatibility with most inorganic/organic fillers, and enhanced composites may be prepared without the need to introduce coupling agents and interfacial modifiers. The patented high amorphous polyvinyl alcohol (HAVOH), commercialized with the trade name G-Polymer, can be easily dispersed in water and melt processed. HAVOH is particularly suitable for extrusion and can be used as a matrix to disperse nanocomposites with different properties. In this work, the optimization of the synthesis and characterization of HAVOH/reduced graphene oxide (rGO) nanocomposite obtained by the solution blending process of HAVOH and Graphene Oxide (GO) water solutions and ‘in situ’ reduction of GO is studied. The produced nanocomposite presents a low percolation threshold (~1.7 wt%) and high electrical conductivity (up to 11 S/m) due to the uniform dispersion ...
this paper reports the experimental results of an on-going project running at lab-scale and aimed... more this paper reports the experimental results of an on-going project running at lab-scale and aimed at the valorization of roasted hazelnut cuticles through both chemical (i.e., solvent extraction) and thermochemical treatment (i.e., torrefaction) routes. In particular, the potential of using water as a green solvent for the extraction of bioactive compounds (i.e., substances of chemical-food-pharmaceutical interest, such as the polyphenols) contained in residues originated by industrial processing of hazelnuts has been investigated, applying the conventional laboratory Soxhlet extraction procedure. A subsequent valorization stage has been explored for the spent post-extraction residues versus the “as collected” ones; they lend themselves to become “renewable” solid fuels thanks to torrefaction, which is a “mild” thermochemical conversion process. The obtained results are first presented in terms of theoretical yields of the bioactive compounds of interest with respect to the original...
Tomato - From Cultivation to Processing Technology [Working Title]
In the last years, the European Commission has been funding numerous projects regarding the valor... more In the last years, the European Commission has been funding numerous projects regarding the valorization of food wastes. Tomato by-products received great attention especially in Spain, Italy, Greece, and Portugal due to high volumes and high concentration of valuable compounds. Among 40 funded projects about the management of tomato wastes in general, 14 projects are strictly connected to the valorization and exploitation of the tomato residues/by-products after processing and are of great interest for their scientific, technical, and economical outcomes. They received an overall budget of around 37 M€ over 35 years, involving 20 European and 4 non-European countries, with project coordinators located in Germany, the Netherlands, and Italy in most of the cases. This chapter delivers general information about these projects, assessing and reporting scientific and technical results. Moreover, the interconnection is highlighted among them by focusing on the contribution they gave to t...
Reduced graphene oxide supporting silver nanoparticles, obtained by an efficient, "green&quo... more Reduced graphene oxide supporting silver nanoparticles, obtained by an efficient, "green" and one step "top- down" solution route, was used for removal from water of chlordane, a known persistent organic pollutants. A two-step mechanism, involving chlordane degradation by Ag nanoparticles and subsequent adsorption of the degraded products: ether bis(2-chloro allyl), 1,10-dichlorodecane and octadecanoid acid were detected, on the reduced graphene oxide surface, leads to a complete removal of chlordane from water solution in only 11 minutes at room temperature.
In this work, a new natural hydrogel containing reduced graphene oxide (RGO) supporting silver (A... more In this work, a new natural hydrogel containing reduced graphene oxide (RGO) supporting silver (Ag) nanoparticles composite were successfully prepared and tested as catalyst for waste water treatment. The formed hydrogels contain a network structure of cross-linked nanosheets decorated with metal nanoparticles. The reported method is based on in situ co-reduction of GO and Ag acetate within the natural hydrogel matrix to form RGO-based composite gel, carried on with a 'green' process. The silver nanoparticles were homogeneously and uniformly dispersed on the surface of the RGO nanosheets. The hybrid acts as catalyst for the reduction of organic pollutants in an aqueous environment, while the natural hydrogels hinders the intrinsic aggregation of the nanofiller, due to the protection of the formed 3-D network, preserving the catalytic activity. Interestingly, the as-prepared catalytic composite matrix structure can be easily handled, e.g. for separation from an aqueous enviro...
The industrial processing of tomato leads to substantial amounts of residues, typically known as ... more The industrial processing of tomato leads to substantial amounts of residues, typically known as tomato pomace or by-products, which can represent as much as 10% by weight of fresh tomatoes. At present, these residues are either used as feedstock for animals or, in the worst case, disposed of in landfills. This represents a significant waste because tomato pomace contains high-value compounds like lycopene, a powerful antioxidant, cutin, which can be used as a starting material for biopolymers, and pectin, a gelling agent. This article presents an overview of technologies that valorize tomato by-products by recovering added-value compounds as well as generating fuel for energy production. These technologies include operations for extraction, separation, and exploitation of lycopene, cutin and pectin, as well as the processes for conversion of the solid residues to fuels. Data collected from the review has been used to develop a biorefinery scheme with the related mass flow balance, ...
Three-dimensional (3D) printing is often considered synonymous with additive manufacturing. Sever... more Three-dimensional (3D) printing is often considered synonymous with additive manufacturing. Several types of 3D printer are known where polymers are usually used. Stereolithography (SLA) employs a single beam laser to polymerize or crosslink a photopolymer resin. By drawing on the liquid photopolymer resin with a light beam, thin layers of polymer are stacked layer by layer. Elastomer based on polydimethysiloxanes (PDMS) are an important class of materials, because of properties such as chemical inertness, flexibility, and optical transparence. In addition, they have a very low surface tension (20.4 mN/m) and glass transition temperatures (146 K). it is possible to print a support material that holds the PDMS prepolymer in place until it can be cured by UV light using a photoactive cross-linking agent. It is possible to graft photoactive group on PDMS backbone and obtain a new UV curable polymer [1,2]. The aim of the presented work is to obtain photopolymers based on PDMS [3]. For t...
This contribution is a piece of work within a more comprehensive research program dedicated to a ... more This contribution is a piece of work within a more comprehensive research program dedicated to a thorough exploitation of industrial tomato by-products, which should be technically feasible, economically convenient and environmentally friendly. In this respect, the proposed paper focuses three aspects of newer and broader interest: lycopene extraction, cutin separation and compost production. The investigated case study refers to the tomato industry in the Campania region (IT). The lycopene extraction from peels is usually carried out by a solventor supercritical CO2-assisted operation; the separation of cutin is performed in two process steps: alkaline hydrolysis and acidification. The solid residual, after cutin separation, is proposed to be used as feedstock for composting, not alone, but mixed with other suitable biomass to adjust both the final moisture content and C/N ratio. To this end, two scenarios according to the “biorefinery cascade approach” were developed that differ i...
Graphene-based materials in different configuration have been subject of intense investigation an... more Graphene-based materials in different configuration have been subject of intense investigation and have proven excellent candidates as electrode material for supercapacitors [1]. Recently, researchers have been focused their attention on the exploitation of the reduced graphene oxide electrochemical properties [2]. Although reduced graphene oxide is light-weight, highly flexible and electrically conductive, the restacking between individual graphene sheets, dramatically lowers the large initial surface area leading to limited specific capacitance values. Metal oxides and conductive polymers have been used as spacers to avoid graphene restacking and improve performances. Although metals are provided with high electrical conductive and able to give pseudocapacitance, they are rarely studied in combination with graphene [3]. In this work, we demonstrated an efficient, “green” and one step “top-down” solution route for the preparation of silver nanoparticles decorated graphene (rGO_Ag) ...
The aim of this work is to model a more environmental-friendly production of biodiesel from tomat... more The aim of this work is to model a more environmental-friendly production of biodiesel from tomato seed oil to assess the feasibility of using an alternative catalyst. The AspenPlus® software is used to this end. Different cases are evaluated and compared, by changing the catalyst and by considering the additional production of high purity glycerol and potassium phosphate. Tomato seed oil obtained from tomato pomace coming from local industries, methanol and catalyst are considered as raw materials. Based on literature data, a methylesters yield formulation is developed and the catalytic transesterification reaction implemented in a simulated reactor, while methanol is recovered by distillation and recycled to the reactor. The necessary distillation towers are designed. All the mass and energy balances were set up for the whole process. The energy return of investment (EROI) was determined by considering the energy for harvesting and that for producing biodiesel. Results show that t...
The aim of this work is to model the extraction of pectin from tomato peels using different acids... more The aim of this work is to model the extraction of pectin from tomato peels using different acids that could be more environmentally friendly. The AspenPlus® software is used to this end. Several cases, such as considering different extracting acids, the recycle of water and washing solvent streams are evaluated and compared. Tomato peels seasonally generated by factories in a local district, were considered as raw materials, as well as methanol and catalyst. Based on literature data and using Excel® worksheet, the mass and energy balances were set up for the extraction reactor and, hence, a pectin extraction yields up to 25 % and 17 %, for two different scenarios, was determined, while the washing and purification stages were simulated and optimized in AspenPlus®. The distillation tower for solvent recover was designed. The economic potential of these cases was calculated by considering utilities cost, product and by-product sales, wastewater treatment as well as raw material costs...
Backside tungsten coating of copper foils allows for the chemical vapor deposition of exclusively... more Backside tungsten coating of copper foils allows for the chemical vapor deposition of exclusively single-layer graphene sheets.
Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by ... more Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by an easy and low-cost method of melt blending of preliminary grinded poly(lactic acid) (PLA) with nanosized carbon fillers used as powder. Morphological, structural and mechanical properties were investigated to reveal the influence of carbon nanofiller on the PLA–based composite. The dependence of tensile strength on nanocomposite loading was defined by a series of experiments over extruded filaments using a universal mechanical testing instrument. The applying the XRD technique disclosed that compounds crystallinity significantly changed upon addition of multi walled carbon nanotubes. We demonstrated that Raman spectroscopy can be used as a quick and unambiguous method to determine the homogeneity of the nanocomposites in terms of carbon filler dispersion in a polymer matrix.
Decoration with silver nanoparticles was obtained by coating graphene with a polydopamine layer, ... more Decoration with silver nanoparticles was obtained by coating graphene with a polydopamine layer, able to induce spontaneous metallic nanoparticles formation without any specific chemical interfacial modifier, neither using complex instrumentation. The choice of dopamine was inspired by the composition of adhesive proteins in mussels, related to their robust attach to solid surfaces. The synthesis procedure started from graphite and involved eco-friendly compounds, such as Vitamin C and glucose as reducing agent and water as reaction medium. Silver decorated graphene was inserted as secondary nanofiller in the formulation of a reference conductive adhesive based on epoxy resin and silver flakes. A wide characterization of the intermediate materials obtained along the step procedure for the adhesive preparation was carried out by several techniques. We have found that the presence of nanofiller yields, in addition to an improvement of the thermal conductivity (up to 7.6 W/m · K), a dr...
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