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Michel Perrut - One of the best experts on this subject based on the ideXlab platform.

  • particle design using Supercritical Fluids literature and patent survey
    Journal of Supercritical Fluids, 2001
    Co-Authors: Jennifer Jung, Michel Perrut
    Abstract:

    As particle design is presently a major development of Supercritical Fluids applications, mainly in the pharmaceutical, nutraceutical, cosmetic and specialty chemistry industries, number of publications are issued and numerous patents filed every year. This document presents a survey (that cannot pretend to be exhaustive!) of published knowledge classified according to the different concepts currently used to manufacture particles, microspheres or microcapsules, liposomes or other dispersed materials (like microfibers): RESS: This acronym refers to ‘Rapid Expansion of Supercritical Solutions’; this process consists in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle, causing an extremely rapid nucleation of the product into a highly dispersed material. Known for long, this process is attractive due to the absence of organic solvent use; unfortunately, its application is restricted to products that present a reasonable solubility in Supercritical carbon dioxide (low polarity compounds). GAS or SAS: These acronyms refer to ‘Gas (or Supercritical fluid) Anti-Solvent’, one specific implementation being SEDS (‘Solution Enhanced Dispersion by Supercritical Fluids’); this general concept consists in decreasing the solvent power of a polar liquid solvent in which the substrate is dissolved, by saturating it with carbon dioxide in Supercritical conditions, causing the substrate precipitation or recrystallization. According to the solid morphology that is wished, various ways of implementation are available: GAS or SAS recrystallization: This process is mostly used for recrystallization of solid dissolved in a solvent with the aim of obtaining either small size particles or large crystals, depending on the growth rate controlled by the anti-solvent pressure variation rate; ASES: This name is rather used when micro- or nano-particles are expected; the process consists in pulverizing a solution of the substrate(s) in an organic solvent into a vessel swept by a Supercritical fluid; SEDS: A specific implementation of ASES consists in co-pulverizing the substrate(s) solution and a stream of Supercritical carbon dioxide through appropriate nozzles. PGSS: This acronym refers to ‘Particles from Gas-Saturated Solutions (or Suspensions)’: This process consists in dissolving a Supercritical fluid into a liquid substrate, or a solution of the substrate(s) in a solvent, or a suspension of the substrate(s) in a solvent followed by a rapid depressurization of this mixture through a nozzle causing the formation of solid particles or liquid droplets according to the system. The use of Supercritical Fluids as chemical reaction media for material synthesis. Two processes are described: thermal decomposition in Supercritical Fluids and hydrothermal synthesis. We will successively detail the literature and patents for these four main process concepts, and related applications that have been claimed. Moreover, as we believe it is important to take into account the user's point-of-view, we will also present this survey in classifying the documents according three product objectives: particles (micro- or nano-) of a single component, microspheres and microcapsules of mixtures of active and carrier (or excipient) components, and particle coating.

  • Particle design using Supercritical Fluids: Literature and patent survey
    Journal of Supercritical Fluids, 2001
    Co-Authors: Jennifer Jung, Michel Perrut
    Abstract:

    As particle design is presently a major development of Supercritical Fluids applications, mainly in the pharmaceutical, nutraceutical, cosmetic and specialty chemistry industries, number of publications are issued and numerous patents filed every year. This document presents a survey (that cannot pretend to be exhaustive!) of published knowledge classified according to the different concepts currently used to manufacture particles, microspheres or microcapsules, liposomes or other dispersed materials (like microfibers): RESS: This acronym refers to 'Rapid Expansion of Supercritical Solutions'; this process consists in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle, causing an extremely rapid nucleation of the product into a highly dispersed material. Known for long, this process is attractive due to the absence of organic solvent use; unfortunately, its application is restricted to products that present a reasonable solubility in Supercritical carbon dioxide (low polarity compounds). GAS or SAS: These acronyms refer to 'Gas (or Supercritical fluid) Anti-Solvent', one specific implementation being SEDS ('Solution Enhanced Dispersion by Supercritical Fluids'); this general concept consists in decreasing the solvent power of a polar liquid solvent in which the substrate is dissolved, by saturating it with carbon dioxide in Supercritical conditions, causing the substrate precipitation or recrystallization. According to the solid morphology that is wished, various ways of implementation are available: GAS or SAS recrystallization: This process is mostly used for recrystallization of solid dissolved in a solvent with the aim of obtaining either small size particles or large crystals, depending on the growth rate controlled by the anti-solvent pressure variation rate; ASES: This name is rather used when micro- or nano-particles are expected; the process consists in pulverizing a solution of the substrate(s) in an organic solvent into a vessel swept by a Supercritical fluid; SEDS: A specific implementation of ASES consists in co-pulverizing the substrate(s) solution and a stream of Supercritical carbon dioxide through appropriate nozzles. PGSS: This acronym refers to 'Particles from Gas-Saturated Solutions (or Suspensions)': This process consists in dissolving a Supercritical fluid into a liquid substrate, or a solution of the substrate(s) in a solvent, or a suspension of the substrate(s) in a solvent followed by a rapid depressurization of this mixture through a nozzle causing the formation of solid particles or liquid droplets according to the system. The use of Supercritical Fluids as chemical reaction media for material synthesis. Two processes are described: thermal decomposition in Supercritical Fluids and hydrothermal synthesis. We will successively detail the literature and patents for these four main process concepts, and related applications that have been claimed. Moreover, as we believe it is important to take into account the user's point-of-view, we will also present this survey in classifying the documents according three product objectives: particles (micro- or nano-) of a single component, microspheres and microcapsules of mixtures of active and carrier (or excipient) components, and particle coating. © 2001 Elsevier Science B.V.

Motonobu Goto - One of the best experts on this subject based on the ideXlab platform.

  • Graphene exfoliation with Supercritical Fluids
    Carbon Letters, 2020
    Co-Authors: Rodolfo Morales Ibarra, Motonobu Goto, Juan García-serna, Saida Mayela García Montes
    Abstract:

    Graphene is an unconventional material with a two-dimensional hexagonal crystalline array of elemental carbon atoms and outstanding properties; accordingly, a desirable objective in the line of research of graphene is the development of novel and more productive methods of synthesis, validating its properties and applications. In our exploratory research, we have effectively exfoliated graphene from graphite using Supercritical Fluids (water, ethanol and carbon dioxide). The exfoliated graphene was properly characterized; via scanning electron microscopy, the morphology of graphene was observed; Raman spectra confirmed the exfoliation of graphene depicting the characteristic shift towards smaller Raman number in the 2D band (2676 cm^−1) compared to that of graphite (≈ 2700 cm^−1); transmission electron microscopy analysis exhibited the crystalline structure of graphene attesting also the expected transparency of exfoliated layers. Graphene exfoliation from graphite by Supercritical Fluids promises to be a simple large-scale method for graphene production.

  • chemical recycling of plastics using sub and Supercritical Fluids
    Journal of Supercritical Fluids, 2009
    Co-Authors: Motonobu Goto
    Abstract:

    The development of chemical recycling of waste plastics by decomposition reactions in sub- and Supercritical Fluids is reviewed. Decomposition reactions proceed rapidly and selectively using Supercritical Fluids compared to conventional processes. Condensation polymerization plastics such as polyethylene terephthalate (PET), nylon, and polyurethane, are relatively easily depolymerized to their monomers in Supercritical water or alcohols. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Pilot scale or commercial scale plants have been developed and are operating with sub- and Supercritical Fluids.

  • reactions of polymers in Supercritical Fluids for chemical recycling of waste plastics
    Journal of Materials Science, 2006
    Co-Authors: Motonobu Goto, Mitsuru Sasaki, Tsutomu Hirose
    Abstract:

    Sub- or Supercritical Fluids have been focused as reaction media for environmental applications from a view point of green chemistry. Chemical recycling of waste plastics is important issue. We have applied reaction in water or organic solvent in sub- or Supercritical condition to convert polymers into its monomers. Condensed polymers such as polyethylene terephthalate or nylon 6 were depolymerized to its monomers by hydrolysis of alcoholysis in Supercritical water or alcohol. The other polymers such as phenol resin and fiber reinforced plastics (FRP) were also decomposed to small molecules by solvolysis. In this paper, the degradation of polymers studied in our group was reviewed.

Jennifer Jung - One of the best experts on this subject based on the ideXlab platform.

  • particle design using Supercritical Fluids literature and patent survey
    Journal of Supercritical Fluids, 2001
    Co-Authors: Jennifer Jung, Michel Perrut
    Abstract:

    As particle design is presently a major development of Supercritical Fluids applications, mainly in the pharmaceutical, nutraceutical, cosmetic and specialty chemistry industries, number of publications are issued and numerous patents filed every year. This document presents a survey (that cannot pretend to be exhaustive!) of published knowledge classified according to the different concepts currently used to manufacture particles, microspheres or microcapsules, liposomes or other dispersed materials (like microfibers): RESS: This acronym refers to ‘Rapid Expansion of Supercritical Solutions’; this process consists in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle, causing an extremely rapid nucleation of the product into a highly dispersed material. Known for long, this process is attractive due to the absence of organic solvent use; unfortunately, its application is restricted to products that present a reasonable solubility in Supercritical carbon dioxide (low polarity compounds). GAS or SAS: These acronyms refer to ‘Gas (or Supercritical fluid) Anti-Solvent’, one specific implementation being SEDS (‘Solution Enhanced Dispersion by Supercritical Fluids’); this general concept consists in decreasing the solvent power of a polar liquid solvent in which the substrate is dissolved, by saturating it with carbon dioxide in Supercritical conditions, causing the substrate precipitation or recrystallization. According to the solid morphology that is wished, various ways of implementation are available: GAS or SAS recrystallization: This process is mostly used for recrystallization of solid dissolved in a solvent with the aim of obtaining either small size particles or large crystals, depending on the growth rate controlled by the anti-solvent pressure variation rate; ASES: This name is rather used when micro- or nano-particles are expected; the process consists in pulverizing a solution of the substrate(s) in an organic solvent into a vessel swept by a Supercritical fluid; SEDS: A specific implementation of ASES consists in co-pulverizing the substrate(s) solution and a stream of Supercritical carbon dioxide through appropriate nozzles. PGSS: This acronym refers to ‘Particles from Gas-Saturated Solutions (or Suspensions)’: This process consists in dissolving a Supercritical fluid into a liquid substrate, or a solution of the substrate(s) in a solvent, or a suspension of the substrate(s) in a solvent followed by a rapid depressurization of this mixture through a nozzle causing the formation of solid particles or liquid droplets according to the system. The use of Supercritical Fluids as chemical reaction media for material synthesis. Two processes are described: thermal decomposition in Supercritical Fluids and hydrothermal synthesis. We will successively detail the literature and patents for these four main process concepts, and related applications that have been claimed. Moreover, as we believe it is important to take into account the user's point-of-view, we will also present this survey in classifying the documents according three product objectives: particles (micro- or nano-) of a single component, microspheres and microcapsules of mixtures of active and carrier (or excipient) components, and particle coating.

  • Particle design using Supercritical Fluids: Literature and patent survey
    Journal of Supercritical Fluids, 2001
    Co-Authors: Jennifer Jung, Michel Perrut
    Abstract:

    As particle design is presently a major development of Supercritical Fluids applications, mainly in the pharmaceutical, nutraceutical, cosmetic and specialty chemistry industries, number of publications are issued and numerous patents filed every year. This document presents a survey (that cannot pretend to be exhaustive!) of published knowledge classified according to the different concepts currently used to manufacture particles, microspheres or microcapsules, liposomes or other dispersed materials (like microfibers): RESS: This acronym refers to 'Rapid Expansion of Supercritical Solutions'; this process consists in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle, causing an extremely rapid nucleation of the product into a highly dispersed material. Known for long, this process is attractive due to the absence of organic solvent use; unfortunately, its application is restricted to products that present a reasonable solubility in Supercritical carbon dioxide (low polarity compounds). GAS or SAS: These acronyms refer to 'Gas (or Supercritical fluid) Anti-Solvent', one specific implementation being SEDS ('Solution Enhanced Dispersion by Supercritical Fluids'); this general concept consists in decreasing the solvent power of a polar liquid solvent in which the substrate is dissolved, by saturating it with carbon dioxide in Supercritical conditions, causing the substrate precipitation or recrystallization. According to the solid morphology that is wished, various ways of implementation are available: GAS or SAS recrystallization: This process is mostly used for recrystallization of solid dissolved in a solvent with the aim of obtaining either small size particles or large crystals, depending on the growth rate controlled by the anti-solvent pressure variation rate; ASES: This name is rather used when micro- or nano-particles are expected; the process consists in pulverizing a solution of the substrate(s) in an organic solvent into a vessel swept by a Supercritical fluid; SEDS: A specific implementation of ASES consists in co-pulverizing the substrate(s) solution and a stream of Supercritical carbon dioxide through appropriate nozzles. PGSS: This acronym refers to 'Particles from Gas-Saturated Solutions (or Suspensions)': This process consists in dissolving a Supercritical fluid into a liquid substrate, or a solution of the substrate(s) in a solvent, or a suspension of the substrate(s) in a solvent followed by a rapid depressurization of this mixture through a nozzle causing the formation of solid particles or liquid droplets according to the system. The use of Supercritical Fluids as chemical reaction media for material synthesis. Two processes are described: thermal decomposition in Supercritical Fluids and hydrothermal synthesis. We will successively detail the literature and patents for these four main process concepts, and related applications that have been claimed. Moreover, as we believe it is important to take into account the user's point-of-view, we will also present this survey in classifying the documents according three product objectives: particles (micro- or nano-) of a single component, microspheres and microcapsules of mixtures of active and carrier (or excipient) components, and particle coating. © 2001 Elsevier Science B.V.

Cyril Aymonier - One of the best experts on this subject based on the ideXlab platform.

  • Review on materials science and Supercritical Fluids
    Current Opinion in Solid State and Materials Science, 2020
    Co-Authors: François Cansell, Cyril Aymonier, Anne Loppinet-serani
    Abstract:

    International audienceSome Supercritical Fluids are able to replace toxic industrial solvents. So, from an industrial point of view, Supercritical Fluids are widely used in many fields such as pharmacy, food industry and environment. From a scientific point of view, the main interest of Supercritical Fluids is connected to the possibility to adjust continuously the physicochemical properties of these reactive media, such as selectivity, solvation, solubility or reactivity..

  • Prospects of Supercritical Fluids in Realizing Graphene-Based Functional Materials.
    Advanced Materials, 2016
    Co-Authors: Suchithra Padmajan Sasikala, Philippe Poulin, Cyril Aymonier
    Abstract:

    Supercritical-Fluids science and technology predate all the approaches that are currently established for graphene production by several decades in advanced materials design. However, it has only recently been proposed as a plausible approach for graphene processing. Since then, Supercritical Fluids have emerged into contention as an alternative to existing technologies because of their scalability and versatility in processing graphene materials, which include composites, aerogels, and foams. Here, an overview is presented of such materials prepared through Supercritical Fluids from an advanced materials science standpoint, with a discussion on their fundamental properties and technological applications. The benefits of Supercritical-fluid processing over conventional liquid-phase processing are presented. The benefits include not only better performances for advanced applications but also environmental issues associated with the synthesis process. Nevertheless, the limitations of Supercritical-fluid processing are also stressed, along with challenges that are still faced toward the achievement of the great expectations from graphene materials.

  • design of functional nanostructured materials using Supercritical Fluids
    Journal of Supercritical Fluids, 2009
    Co-Authors: François Cansell, Cyril Aymonier
    Abstract:

    Abstract This paper describes how the specific properties of Supercritical Fluids have been exploited in the last 5 years for synthesizing functional nanostructured materials, especially in the field of inorganic and hybrid materials. It is shown that control of the physicochemical properties of nanomaterials (size, morphology, structure and composition) as “nanobricks” is achieved by choosing specific operating parameters. Next, the structure formation of these “nanobricks” is discussed in order to design advanced nanostructured materials. This is illustrated with the design of nanorods, nanowires, conformational films, core–shell structure, supported nanoparticles, polymer impregnation with nanoparticles and organic coating of particles. The associated properties for applications in many interesting fields, such as catalysis, electronics, energy, optics, etc. are reported.

  • Review on materials science and Supercritical Fluids
    Current Opinion in Solid State & Materials Science, 2003
    Co-Authors: François Cansell, Cyril Aymonier, Anne Loppinet-serani
    Abstract:

    Some Supercritical Fluids are able to replace toxic industrial solvents. So, from an industrial point of view, Supercritical Fluids are widely used in many fields such as pharmacy, food industry and environment. From a scientific point of view, the main interest of Supercritical Fluids is connected to the possibility to adjust continuously the physicochemical properties of these reactive media, such as selectivity, solvation, solubility or reactivity. In this paper, we present recent work on processes using Supercritical media for processing materials related to fine particle synthesis, porous materials synthesis, polymer synthesis and surface modifications.

Renata Adami - One of the best experts on this subject based on the ideXlab platform.

  • Supercritical Fluids processing of polymers for pharmaceutical and medical applications
    Journal of Supercritical Fluids, 2009
    Co-Authors: Ernesto Reverchon, Renata Adami, Stefano Cardea, Giovanna Della Porta
    Abstract:

    Abstract A critical analysis is presented of the Supercritical Fluids based technologies that have been proposed in polymer processing for pharmaceutical and medical applications. The formation of polymer–drug microparticles and microspheres, the production of simple or loaded membranes and the formation of temporary scaffolds are reviewed and the future trends in these areas are analyzed.

  • nanomaterials and Supercritical Fluids
    Journal of Supercritical Fluids, 2006
    Co-Authors: Ernesto Reverchon, Renata Adami
    Abstract:

    Abstract The interest in the preparation and application of nanometer size materials is increasing since they can exhibit properties of great industrial interest. Several techniques have been proposed to produce nanomaterials using Supercritical Fluids. These processes, taking advantage of the specific properties of Supercritical Fluids, are generally flexible, more simplified and with a reduced enviromental impact. The result is that nanomaterials with potentially better performances have been obtained. We propose a critical review of the Supercritical based techniques applied to the production of nanoparticles, nanofibers, nanowires, nanotubes, nanofilms and nanostructured materials. The most relevant characteristics of each process and the kind of nanomaterial that can be produced are highlighted.