The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Chun Hui Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Current fundamental and applied research into Clay Minerals in China
    Applied Clay Science, 2016
    Co-Authors: Chun Hui Zhou, Li Zhi Zhao, Aiqin Wang, Tian Hu Chen
    Abstract:

    This paper briefly examines current fundamental and applied research into Clay Minerals in China. A collection of studies from Chinese Clay scientists and as a special issue suggests that investigations into the genesis and mineralogy of Clay Minerals for geology and geochemistry, synthetic Clay Minerals, the modification of Clay Minerals for advanced materials, comprehensive and reutilization of Clay Minerals are important aspects of fundamental and applied Clay science within China. Effort is being made to increase the understanding of the genesis and evolution of Clay Minerals and such knowledge is believed to have scientific implication for paleogeographical, paleoecological, and paleoclimatic conditions and to have applications in mining and processing Clay Minerals and related environmental and ecological management. Studies on the modification of Clay Minerals by Chinese Clay scientists aim predominantly to make functional Clay mineral-polymer nanocomposites, adsorbents, catalysts, and biomaterials. In China, increasingly strict management of natural resources and environment, and an increasing demand for value-added Clay-based products, along with the requirements for the sustainability of using Clay mineral resources, offer opportunities and challenges to Chinese Clay scientists and Clay community.

  • Immobilization of enzymes on Clay Minerals for biocatalysts and biosensors
    Applied Clay Science, 2015
    Co-Authors: Chun Hui Zhou, Xiao Yu Zhuang, Dongshen Tong
    Abstract:

    Abstract Many studies suggest that naturally-occurring layered Clay Minerals can be used as a class of biocompatible solid supports for immobilizing enzymes. The corresponding Clay mineral enzyme hybrids prove to have great potentials in catalysis and biosensing. This article reviews latest advances in using Clay Minerals as supports for the immobilization of enzymes. The immobilization of enzyme onto Clay Minerals can be made via non-covalent adsorption and covalent bonding. The non-covalent immobilization involves van der Waals forces, electrostatic interactions, hydrogen bonding, and hydrophobic interactions. For avoiding desorption of enzymes, immobilization can be conducted through direct covalent bonding between enzymes and Clay Minerals. Organic modification of Clay Minerals and addition of linking molecules are made to improve the immobilization so as to increase the loading, activity and stability of enzymes. Regarding the applications of enzyme immobilized on Clay Minerals, recent studies are made mainly in biocatalytic processes and in biosensors. For manufacturing biosensing electrodes, Clay Minerals with metal nanoparticles, graphene and carbon nanotubes prove to be more effective owing mainly to the enhanced electron transfer. Future work on Clay mineral enzyme hybrids could lie in integrating more additional functional materials with Clay mineral enzyme hybrids to build hierarchical structured catalysts and electrodes.

  • adsorption of proteins and nucleic acids on Clay Minerals and their interactions a review
    Applied Clay Science, 2013
    Co-Authors: Dongshen Tong, Chun Hui Zhou, Chun Xiang Lin
    Abstract:

    The understanding of adsorption of proteins and nucleic acids on Clay Minerals and their interactions is important in biological applications for soil ecosystem, the earth's biochemical evolution and origin of life, delivery of drug, etc. This review summarizes adsorption of proteins and nucleic acids (DNA, RNA) on natural Clay Minerals of layer phyllosilicates such as montmorillonite, kaolinite and illite and their interactions. Recent advances in adsorption mechanisms, adsorption sites and effect of various factors on adsorption are discussed. The interaction mechanisms are suggested to be cation exchange, electrostatic interactions, hydrophobic/hydrophilic interactions, ligand exchange, cation bridge, water bridge, hydrogen bond and van der Waals forces. The physical and chemical characteristics of Clay Minerals and proteins and nucleic acids are mainly responsible for the absorption of these biomolecules by Clay Minerals besides external conditions, for instance pH and ion strength of absorption solution. Finally, comments on the perspectives and potential benefits of the studies on adsorption of proteins and nucleic acids on Clay Minerals and their interactions are also made.

  • fundamental and applied research on Clay Minerals from climate and environment to nanotechnology
    Applied Clay Science, 2013
    Co-Authors: Chun Hui Zhou, John Keeling
    Abstract:

    Abstract This brief overview comments on recent trends in scientific research and development of Clay Minerals and was stimulated by the compilation of papers for this special issue to pay tribute to the 34th International Geological Congress held in 2012. The essentially geological context of the conference was a reminder that increased understanding of the genesis and evolution of Clays and Clay Minerals provides insights that have applications in mining, environmental management, paleoclimate, Earth and extraterrestrial sciences. The requirement for multidisciplinary knowledge, including geology, mineralogy, chemistry and materials science, and modern instrumentation and analysis of Clay Minerals, is essential to a full understanding of the genesis, role and potential new uses for these fine-grained industrial Minerals. Latest studies are typically focused on processing and modifying of Clay Minerals as adsorbents, catalysts, and biomaterials. The emphasis for future work is on advanced Clay-based nanomaterials for use in new approaches to sustainable energy, green environment, and human health.

  • Chapter 7.2 - Synthesis of Clay Minerals
    Developments in Clay Science, 2013
    Co-Authors: M. Jaber, S. Komarneni, Chun Hui Zhou
    Abstract:

    Many useful Clay Minerals are not available in sufficient quantities in nature. Actually, two major problems are encountered in the uses of Clay Minerals, (i) the depletion of the natural deposits, especially those with easy access for mining and (ii) the occurrence as mixtures of several phases. To overcome these problems, laboratory syntheses of Clay Minerals recently attracted particular interest of scientists in the fields of material science, geology, chemistry, and geochemistry. This chapter provides a comprehensive survey on the synthesis of different Clay Minerals such as kaolinites, montmorillonites, beidellites, hectorites (Laponite) including the direct synthesis of organohectorites, saponites, and chlorites. Also reported is the technique to hydrothermally synthesize Clay Minerals with direct incorporation of diverse organic groups. A recent development is the one-step synthesis of layered inorganic-organic materials resembling the parent talc structure.

César Viseras - One of the best experts on this subject based on the ideXlab platform.

  • Clay Minerals in drug delivery systems
    Modified Clay and Zeolite Nanocomposite Materials, 2019
    Co-Authors: Fátima García-villén, Pilar Cerezo, E. Carazo, César Viseras, Ana Borrego-sánchez, Rita Sánchez-espejo, Carola Aguzzi
    Abstract:

    Abstract Clay Minerals have been used as pharmaceutical ingredients since ancient times, and continue to be one of the most versatile inorganic excipients nowadays. Particularly, they have attracted an increasing interest in the last several years in the development of modified drug delivery systems (MDDS), designed to improve drug bioavailability and/or reduce side effects. Clayey MDDS result from interactions between some natural, purified, and/or modified Clay Minerals and active molecules. The resultant hybrids show improved biopharmaceutical characteristics induced by the Clay mineral functionality (carrier). Sometimes, Clay Minerals are combined with biopolymers to obtain nanocomposites with the required drug delivery performances, according to the necessities of a particular drug. More particularly, Clay mineral/polymer nanocomposites are currently on top of the most used systems to ameliorate release profiles of drugs intended for long-term treatments, anticancer, and gene therapies. This chapter will be focused on the most recent advances made on Clay-based drug delivery systems.

  • Health and Medical Applications of Tubular Clay Minerals
    Developments in Clay Science, 2016
    Co-Authors: Carola Aguzzi, Giuseppina Sandri, Pilar Cerezo, E. Carazo, César Viseras
    Abstract:

    Abstract Nanosized tubular Clay Minerals such as halloysite and imogolite have attracted a great deal of interest in the last several years as materials intended for drug delivery, tissue engineering and medical devices and diagnostics. Transferring the acquired knowledge to clinical practice and adequate cost-effectiveness in comparison to conventional alternatives are two of the challenges for the medical application of such tubular Clay Minerals. Basic research is needed to fully understand the underlying interaction mechanism between the nanosized tubular Clay Minerals and host drugs, genes and biological matter. These Clay Minerals have demonstrated their possibilities in both target delivery and diagnostics, and it is expected that in the near future, they will be used in theranostic platforms that can carry out an in situ, comprehensive diagnostic, and then deliver drugs, genes or both to the diseased tissue or cell and monitor the resultant therapeutic response. This is the new frontier of nanosized tubular Clay Minerals in health-care applications.

  • Current challenges in Clay Minerals for drug delivery
    Applied Clay Science, 2010
    Co-Authors: César Viseras, Pilar Cerezo, R. Sánchez, I. Salcedo, Carola Aguzzi
    Abstract:

    Abstract This study reviews current challenges of Clay Minerals for drug delivery. Clay Minerals are widely used in conventional pharmaceutical dosage forms both as excipients and active agents. Clay Minerals may interact with drug molecules, but also with inactive components of medicinal products such as polymers. On the basis of these interactions, Clay Minerals and their modified forms can be effectively used to modify drug delivery systems. In this research area, recent advances include the use of montmorillonite and saponite to retain drug molecules and control their release. Synthetic analogues such as Laponite and layered double hydroxides are also being used for biopharmaceutical and technological purposes. Another interesting strategy is the preparation of composites with Clay mineral particles in polymeric matrices to obtain different systems (films, nanoparticles, hydrogels, matrices…) with improved pharmaceutical properties compared to the single components.

Carola Aguzzi - One of the best experts on this subject based on the ideXlab platform.

  • Clay Minerals in drug delivery systems
    Modified Clay and Zeolite Nanocomposite Materials, 2019
    Co-Authors: Fátima García-villén, Pilar Cerezo, E. Carazo, César Viseras, Ana Borrego-sánchez, Rita Sánchez-espejo, Carola Aguzzi
    Abstract:

    Abstract Clay Minerals have been used as pharmaceutical ingredients since ancient times, and continue to be one of the most versatile inorganic excipients nowadays. Particularly, they have attracted an increasing interest in the last several years in the development of modified drug delivery systems (MDDS), designed to improve drug bioavailability and/or reduce side effects. Clayey MDDS result from interactions between some natural, purified, and/or modified Clay Minerals and active molecules. The resultant hybrids show improved biopharmaceutical characteristics induced by the Clay mineral functionality (carrier). Sometimes, Clay Minerals are combined with biopolymers to obtain nanocomposites with the required drug delivery performances, according to the necessities of a particular drug. More particularly, Clay mineral/polymer nanocomposites are currently on top of the most used systems to ameliorate release profiles of drugs intended for long-term treatments, anticancer, and gene therapies. This chapter will be focused on the most recent advances made on Clay-based drug delivery systems.

  • Health and Medical Applications of Tubular Clay Minerals
    Developments in Clay Science, 2016
    Co-Authors: Carola Aguzzi, Giuseppina Sandri, Pilar Cerezo, E. Carazo, César Viseras
    Abstract:

    Abstract Nanosized tubular Clay Minerals such as halloysite and imogolite have attracted a great deal of interest in the last several years as materials intended for drug delivery, tissue engineering and medical devices and diagnostics. Transferring the acquired knowledge to clinical practice and adequate cost-effectiveness in comparison to conventional alternatives are two of the challenges for the medical application of such tubular Clay Minerals. Basic research is needed to fully understand the underlying interaction mechanism between the nanosized tubular Clay Minerals and host drugs, genes and biological matter. These Clay Minerals have demonstrated their possibilities in both target delivery and diagnostics, and it is expected that in the near future, they will be used in theranostic platforms that can carry out an in situ, comprehensive diagnostic, and then deliver drugs, genes or both to the diseased tissue or cell and monitor the resultant therapeutic response. This is the new frontier of nanosized tubular Clay Minerals in health-care applications.

  • Current challenges in Clay Minerals for drug delivery
    Applied Clay Science, 2010
    Co-Authors: César Viseras, Pilar Cerezo, R. Sánchez, I. Salcedo, Carola Aguzzi
    Abstract:

    Abstract This study reviews current challenges of Clay Minerals for drug delivery. Clay Minerals are widely used in conventional pharmaceutical dosage forms both as excipients and active agents. Clay Minerals may interact with drug molecules, but also with inactive components of medicinal products such as polymers. On the basis of these interactions, Clay Minerals and their modified forms can be effectively used to modify drug delivery systems. In this research area, recent advances include the use of montmorillonite and saponite to retain drug molecules and control their release. Synthetic analogues such as Laponite and layered double hydroxides are also being used for biopharmaceutical and technological purposes. Another interesting strategy is the preparation of composites with Clay mineral particles in polymeric matrices to obtain different systems (films, nanoparticles, hydrogels, matrices…) with improved pharmaceutical properties compared to the single components.

Dongshen Tong - One of the best experts on this subject based on the ideXlab platform.

  • Immobilization of enzymes on Clay Minerals for biocatalysts and biosensors
    Applied Clay Science, 2015
    Co-Authors: Chun Hui Zhou, Xiao Yu Zhuang, Dongshen Tong
    Abstract:

    Abstract Many studies suggest that naturally-occurring layered Clay Minerals can be used as a class of biocompatible solid supports for immobilizing enzymes. The corresponding Clay mineral enzyme hybrids prove to have great potentials in catalysis and biosensing. This article reviews latest advances in using Clay Minerals as supports for the immobilization of enzymes. The immobilization of enzyme onto Clay Minerals can be made via non-covalent adsorption and covalent bonding. The non-covalent immobilization involves van der Waals forces, electrostatic interactions, hydrogen bonding, and hydrophobic interactions. For avoiding desorption of enzymes, immobilization can be conducted through direct covalent bonding between enzymes and Clay Minerals. Organic modification of Clay Minerals and addition of linking molecules are made to improve the immobilization so as to increase the loading, activity and stability of enzymes. Regarding the applications of enzyme immobilized on Clay Minerals, recent studies are made mainly in biocatalytic processes and in biosensors. For manufacturing biosensing electrodes, Clay Minerals with metal nanoparticles, graphene and carbon nanotubes prove to be more effective owing mainly to the enhanced electron transfer. Future work on Clay mineral enzyme hybrids could lie in integrating more additional functional materials with Clay mineral enzyme hybrids to build hierarchical structured catalysts and electrodes.

  • adsorption of proteins and nucleic acids on Clay Minerals and their interactions a review
    Applied Clay Science, 2013
    Co-Authors: Dongshen Tong, Chun Hui Zhou, Chun Xiang Lin
    Abstract:

    The understanding of adsorption of proteins and nucleic acids on Clay Minerals and their interactions is important in biological applications for soil ecosystem, the earth's biochemical evolution and origin of life, delivery of drug, etc. This review summarizes adsorption of proteins and nucleic acids (DNA, RNA) on natural Clay Minerals of layer phyllosilicates such as montmorillonite, kaolinite and illite and their interactions. Recent advances in adsorption mechanisms, adsorption sites and effect of various factors on adsorption are discussed. The interaction mechanisms are suggested to be cation exchange, electrostatic interactions, hydrophobic/hydrophilic interactions, ligand exchange, cation bridge, water bridge, hydrogen bond and van der Waals forces. The physical and chemical characteristics of Clay Minerals and proteins and nucleic acids are mainly responsible for the absorption of these biomolecules by Clay Minerals besides external conditions, for instance pH and ion strength of absorption solution. Finally, comments on the perspectives and potential benefits of the studies on adsorption of proteins and nucleic acids on Clay Minerals and their interactions are also made.

  • Synthesis of Clay Minerals
    Applied Clay Science, 2010
    Co-Authors: Di Zhang, Chun Hui Zhou, Chun Xiang Lin, Dongshen Tong
    Abstract:

    Synthetic Clay Minerals provide new choices of layered solids and can be tailored to promote specific properties. They give better understanding of various processes involved in the formation of natural mineral counterparts. This review summarizes recent advancement on synthetic Clay Minerals such as kaolinite, pyrophyllite, mica, smectite, chlorite, and sepiolite. The syntheses were generally performed either at low temperature or at a higher temperature by hydrothermal technology. The crystallization, properties and morphology of synthetic Clay Minerals were influenced by the chemical composition and structure of starting materials as well as hydrothermal conditions. Isomorphous substitution and the influence of such substitution on the structure and morphology of the Clay Minerals were extensively studied. Hydrothermal syntheses of pyrophyllite polymorphs were affected by several factors including anions present in the solution, the state and quantity of the interlayer cation, and counter anion in solution. The effects of fluorine in hydrothermal synthesis were discussed. Organo-montmorillonite and organo-hectorite were obtained by direct incorporation of polymers or organic species during synthesis. The synthesis chemistry provided a better understanding of the formation mechanism, variation in physico-chemical properties and subsequently new applications for Clay Minerals.

Peng Liu - One of the best experts on this subject based on the ideXlab platform.

  • Polymer modified Clay Minerals: A review
    Applied Clay Science, 2007
    Co-Authors: Peng Liu
    Abstract:

    Recent progress in the surface modification of the Clay Minerals with polymers via physical adsorption and chemical grafting are reviewed. The surface modification of Clay Minerals especially with polymers could improve markedly their surface physical and chemical properties so the modified Clay Minerals could be applied as catalysts, adsorbents, in composite materials, and so on.