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Giulio Malucelli - One of the best experts on this subject based on the ideXlab platform.

  • Hybrid Organic/Inorganic Coatings Through Dual-Cure Processes: State of the Art and Perspectives
    Coatings, 2016
    Co-Authors: Giulio Malucelli
    Abstract:

    This paper reviews the current state of the art related to the synthesis and characterization of hybrid organic-Inorganic (O/I) Coatings obtained through the exploitation of dual-cure processes, which involve a photo-induced polymerization followed by a thermal treatment: this latter allows the occurrence of sol-gel reactions of suitable alkoxy precursors already embedded in the UV-curable system. After a brief introduction on hybrid organic-Inorganic Coatings, the first part of the review is focused on the design and feasibility issues provided by the dual-cure method, emphasizing the possibility of tuning the structure of the final hybrid network on the basis of the composition of the starting liquid mixture. Then, some recent examples of hybrid organic-Inorganic networks are thoroughly described, showing their potential advances and the application fields to which they can be addressed.

  • layer by layer complex architectures based on ammonium polyphosphate chitosan and silica on polyester cotton blends flammability and combustion behaviour
    Cellulose, 2012
    Co-Authors: Jenny Alongi, Federico Carosio, Giulio Malucelli
    Abstract:

    Hybrid organic–Inorganic Coatings containing ammonium polyphosphate (APP), chitosan and silica have been deposited on polyester-cotton blends (PET-CO), exploiting the layer by layer assembly. To this aim, two different complex architectures (namely, chitosan/APP bilayers plus silica/silica bilayers or silica/silica/chitosan/APP quadlayers) have been thoroughly investigated. The effect of their morphologies on the flame retardancy properties of the fabrics (flammability and combustion behaviour) has been assessed. More specifically, some of the above complex architectures exhibited significant enhancements concerning flammability (i.e. the suppression of afterglow, together with a considerable final residue increase) and combustion behaviour as evidenced by cone calorimeter tests. A close relationship between the overall flame retardancy properties of the blends and the level of dishomogeneity of the LbL architectures has been shown.

  • thermal stability flame retardancy and mechanical properties of cotton fabrics treated with Inorganic Coatings synthesized through sol gel processes
    Carbohydrate Polymers, 2012
    Co-Authors: Jenny Alongi, Mihaela Diana Ciobanu, Giulio Malucelli
    Abstract:

    Abstract Cotton was sol–gel treated employing several metal alkoxide precursors (namely, tetraethylortho-silicate, -titanate, -zirconate and aluminium isopropylate) in order to get Inorganic phases able to improve the thermal stability and flame retardancy of the fabric, without changing its mechanical features. Indeed, after the sol–gel treatment the fibre/fabric surface was morphologically modified: a homogeneous and compact film located in the fibre interstices (warp and weft) and partially covering their walls was observed for all the systems investigated. These Coatings turned out to be responsible of an overall enhancement of the thermal and fire stability of the fabrics preserving, at the same time, the original mechanical properties of the neat cotton in terms of tensile strength and deformation. In addition, such Inorganic Coatings increased the abrasion resistance of the cotton in a remarkable way.

  • Cotton fabrics treated with hybrid organic–Inorganic Coatings obtained through dual-cure processes
    Cellulose, 2011
    Co-Authors: Jenny Alongi, Mihaela Ciobanu, Giulio Malucelli
    Abstract:

    Cotton fabrics were treated with a hybrid organic–Inorganic coating obtained through a dual-cure process, i.e. a photopolymerization reaction followed by a thermal treatment for promoting the formation of silica phases through a sol–gel process. To this aim, different amounts of a silica precursor were added to an acrylic UV-curable formulation in the presence of a suitable coupling agent. The thermo-mechanical properties of the treated fabrics were investigated and correlated to the composition and morphology of the hybrid organic–Inorganic system. Furthermore, their flame retardancy and combustion behavior were evaluated by flammability tests and cone calorimetry and compared with the performances of pure cotton.

  • cotton fabrics treated with hybrid organic Inorganic Coatings obtained through dual cure processes
    Cellulose, 2011
    Co-Authors: Jenny Alongi, Mihaela Diana Ciobanu, Giulio Malucelli
    Abstract:

    Cotton fabrics were treated with a hybrid organic–Inorganic coating obtained through a dual-cure process, i.e. a photopolymerization reaction followed by a thermal treatment for promoting the formation of silica phases through a sol–gel process. To this aim, different amounts of a silica precursor were added to an acrylic UV-curable formulation in the presence of a suitable coupling agent. The thermo-mechanical properties of the treated fabrics were investigated and correlated to the composition and morphology of the hybrid organic–Inorganic system. Furthermore, their flame retardancy and combustion behavior were evaluated by flammability tests and cone calorimetry and compared with the performances of pure cotton.

Jenny Alongi - One of the best experts on this subject based on the ideXlab platform.

  • layer by layer complex architectures based on ammonium polyphosphate chitosan and silica on polyester cotton blends flammability and combustion behaviour
    Cellulose, 2012
    Co-Authors: Jenny Alongi, Federico Carosio, Giulio Malucelli
    Abstract:

    Hybrid organic–Inorganic Coatings containing ammonium polyphosphate (APP), chitosan and silica have been deposited on polyester-cotton blends (PET-CO), exploiting the layer by layer assembly. To this aim, two different complex architectures (namely, chitosan/APP bilayers plus silica/silica bilayers or silica/silica/chitosan/APP quadlayers) have been thoroughly investigated. The effect of their morphologies on the flame retardancy properties of the fabrics (flammability and combustion behaviour) has been assessed. More specifically, some of the above complex architectures exhibited significant enhancements concerning flammability (i.e. the suppression of afterglow, together with a considerable final residue increase) and combustion behaviour as evidenced by cone calorimeter tests. A close relationship between the overall flame retardancy properties of the blends and the level of dishomogeneity of the LbL architectures has been shown.

  • thermal stability flame retardancy and mechanical properties of cotton fabrics treated with Inorganic Coatings synthesized through sol gel processes
    Carbohydrate Polymers, 2012
    Co-Authors: Jenny Alongi, Mihaela Diana Ciobanu, Giulio Malucelli
    Abstract:

    Abstract Cotton was sol–gel treated employing several metal alkoxide precursors (namely, tetraethylortho-silicate, -titanate, -zirconate and aluminium isopropylate) in order to get Inorganic phases able to improve the thermal stability and flame retardancy of the fabric, without changing its mechanical features. Indeed, after the sol–gel treatment the fibre/fabric surface was morphologically modified: a homogeneous and compact film located in the fibre interstices (warp and weft) and partially covering their walls was observed for all the systems investigated. These Coatings turned out to be responsible of an overall enhancement of the thermal and fire stability of the fabrics preserving, at the same time, the original mechanical properties of the neat cotton in terms of tensile strength and deformation. In addition, such Inorganic Coatings increased the abrasion resistance of the cotton in a remarkable way.

  • Cotton fabrics treated with hybrid organic–Inorganic Coatings obtained through dual-cure processes
    Cellulose, 2011
    Co-Authors: Jenny Alongi, Mihaela Ciobanu, Giulio Malucelli
    Abstract:

    Cotton fabrics were treated with a hybrid organic–Inorganic coating obtained through a dual-cure process, i.e. a photopolymerization reaction followed by a thermal treatment for promoting the formation of silica phases through a sol–gel process. To this aim, different amounts of a silica precursor were added to an acrylic UV-curable formulation in the presence of a suitable coupling agent. The thermo-mechanical properties of the treated fabrics were investigated and correlated to the composition and morphology of the hybrid organic–Inorganic system. Furthermore, their flame retardancy and combustion behavior were evaluated by flammability tests and cone calorimetry and compared with the performances of pure cotton.

  • cotton fabrics treated with hybrid organic Inorganic Coatings obtained through dual cure processes
    Cellulose, 2011
    Co-Authors: Jenny Alongi, Mihaela Diana Ciobanu, Giulio Malucelli
    Abstract:

    Cotton fabrics were treated with a hybrid organic–Inorganic coating obtained through a dual-cure process, i.e. a photopolymerization reaction followed by a thermal treatment for promoting the formation of silica phases through a sol–gel process. To this aim, different amounts of a silica precursor were added to an acrylic UV-curable formulation in the presence of a suitable coupling agent. The thermo-mechanical properties of the treated fabrics were investigated and correlated to the composition and morphology of the hybrid organic–Inorganic system. Furthermore, their flame retardancy and combustion behavior were evaluated by flammability tests and cone calorimetry and compared with the performances of pure cotton.

Abdul Malik - One of the best experts on this subject based on the ideXlab platform.

  • germania based sol gel hybrid organic Inorganic Coatings for capillary microextraction and gas chromatography
    Analytical Chemistry, 2007
    Co-Authors: Li Fang, Sameer S Kulkarni, Khalid Alhooshani, Abdul Malik
    Abstract:

    Germania-based, sol−gel hybrid organic−Inorganic Coatings were developed for capillary microextraction and gas chromatography (GC). Being an isostructural analogue of SiO2, GeO2 is compatible with the silica network. Because of this similarity, germania-based materials possess great potential for being used in the areas of chromatographic separation and sample preparation. These possibilities, however, remain practically unexplored. To our knowledge, this is the first instance that a germania-based hybrid sol−gel material is used as a sorbent in analytical sample preparation or chromatographic separation. Tetramethoxygermane was used as a precursor to create a sol−gel network via hydrolytic polycondensation reactions performed within a fused-silica capillary. The growing sol−gel germania network was simultaneously reacted with an organic ligand that contained sol−gel-active sites in its chemical structure. Three different sol−gel-active ligands were used:  (a) hydroxy-terminated poly(dimethylsiloxane), (b...

  • Germania-based, sol-gel hybrid organic-Inorganic Coatings for capillary microextraction and gas chromatography.
    Analytical chemistry, 2007
    Co-Authors: Li Fang, Sameer S Kulkarni, Khalid Alhooshani, Abdul Malik
    Abstract:

    Germania-based, sol-gel hybrid organic-Inorganic Coatings were developed for capillary microextraction and gas chromatography (GC). Being an isostructural analogue of SiO2, GeO2 is compatible with the silica network. Because of this similarity, germania-based materials possess great potential for being used in the areas of chromatographic separation and sample preparation. These possibilities, however, remain practically unexplored. To our knowledge, this is the first instance that a germania-based hybrid sol-gel material is used as a sorbent in analytical sample preparation or chromatographic separation. Tetramethoxygermane was used as a precursor to create a sol-gel network via hydrolytic polycondensation reactions performed within a fused-silica capillary. The growing sol-gel germania network was simultaneously reacted with an organic ligand that contained sol-gel-active sites in its chemical structure. Three different sol-gel-active ligands were used: (a) hydroxy-terminated poly(dimethylsiloxane), (b) hydroxy-terminated poly(dimethyldiphenylsiloxane), and (c) 3-aminopropyltrimethoxysilane. Sol-gel germania-coated capillaries of desired polarity and extraction selectivity were prepared by using an appropriately selected sol-gel-active ligand in the sol solution. These capillaries were further used to extract trace concentrations of polycyclic aromatic hydrocarbons, aldehydes, ketones, alcohols, phenols, and free fatty acids from aqueous samples. The extracted solutes were further analyzed by GC-FID. The new germania-based Coatings showed excellent stability under harsh operation conditions involving extreme pH values, high temperatures, and aggressive solvents. Our preliminary results also indicate that sol-gel hybrid germania Coatings have the potential to offer great analytical performance as GC stationary phases.

Rizza G (rizza G.) - One of the best experts on this subject based on the ideXlab platform.

  • Hybrid organic-Inorganic Coatings based on thiol-ene systems
    Reactive and Functional Polymers, 2009
    Co-Authors: Sangermano M (sangermano M.), Colucci G (colucci G.), Fragale M (fragale M.), Rizza G (rizza G.)
    Abstract:

    Hybrid organic-Inorganic Coatings based on thiol-ene systems were obtained by a UV-thermal dual-curing process. An improvement in mechanical properties and surface hardness was achieved because of the presence of the Inorganic filler generated in situ via the sol-gel process. TEM analysis clearly evidenced the reduction of the nanosize dimensions of the Inorganic silica domains by increasing the coupling agent content in the photocurable formulation

Giancarlo Rizza - One of the best experts on this subject based on the ideXlab platform.

  • Hybrid organic–Inorganic Coatings based on thiol-ene systems
    Reactive and Functional Polymers, 2009
    Co-Authors: Marco Sangermano, Giovanna Colucci, M. Fragale, Giancarlo Rizza
    Abstract:

    Abstract Hybrid organic–Inorganic Coatings based on thiol-ene systems were obtained by a UV-thermal dual-curing process. An improvement in mechanical properties and surface hardness was achieved because of the presence of the Inorganic filler generated in situ via the sol–gel process. TEM analysis clearly evidenced the reduction of the nanosize dimensions of the Inorganic silica domains by increasing the coupling agent content in the photocurable formulation.