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John F. Brown

Bio: John F. Brown is an academic researcher. The author has contributed to research in topics: Infrared spectroscopy & Difluoride. The author has an hindex of 10, co-authored 11 publications receiving 1566 citations.


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Journal ArticleDOI
TL;DR: This paper presents a meta-analysis of four-Wave Mixing and its applications in nanofiltration, which shows clear trends in high-performance liquid chromatography and also investigates the role of nano-magnifying lens technology in this process.
Abstract: 12.2.2. Four-Wave Mixing (FWM) 4849 12.2.3. Dye Aggregation 4850 12.2.4. Optoelectronic Nanodevices 4850 12.3. Sensor 4851 12.3.1. Chemical Sensor 4851 12.3.2. Biological Sensor 4851 12.4. Catalysis 4852 13. Conclusion and Perspectives 4852 14. Abbreviations 4853 15. Acknowledgements 4854 16. References 4854 * Corresponding author E-mail: tpal@chem.iitkgp.ernet.in. † Raidighi College. § Indian Institute of Technology. 4797 Chem. Rev. 2007, 107, 4797−4862

2,414 citations

Journal ArticleDOI
TL;DR: In this paper, the core integrity of inorganic nanobuilding blocks (NBBs) is preserved and the main synthetic procedures presented in the literature are reviewed and extended to nanoparticule-based hybrid networks.
Abstract: This article describes hybrid materials and systems in which the core integrity of inorganic nanobuilding blocks (NBBs) is preserved and reviews the main synthetic procedures presented in the literature. The relation between the NBB and the resulting hybrid networks is discussed for several striking examples: silicon and tin oxo clusters, polyoxometalates, and transition metal−oxo-based clusters. This approach is extended to nanoparticule-based hybrids. The chemical strategies offered by the coupling of soft chemistry processes and this approach based on functional NBBs allows, through an intelligent and tuned coding, to develop a new vectorial chemistry that is able to direct the assembly of a large variety of structurally well-defined clusters or nanoparticles into complex architectures.

1,124 citations

Journal ArticleDOI
TL;DR: It has become increasingly apparent that the behavior of Lewis bases as agents for promoting chemical reactions is not merely as an electronic complement of the cognate Lewis acids: in fact Lewis bases are capable of enhancing both the electrophilic and nucleophilic character of molecules to which they are bound.
Abstract: The legacy of Gilbert Newton Lewis (1875-1946) pervades the lexicon of chemical bonding and reactivity. The power of his concept of donor-acceptor bonding is evident in the eponymous foundations of electron-pair acceptors (Lewis acids) and donors (Lewis bases). Lewis recognized that acids are not restricted to those substances that contain hydrogen (Bronsted acids), and helped overthrow the "modern cult of the proton". His discovery ushered in the use of Lewis acids as reagents and catalysts for organic reactions. However, in recent years, the recognition that Lewis bases can also serve in this capacity has grown enormously. Most importantly, it has become increasingly apparent that the behavior of Lewis bases as agents for promoting chemical reactions is not merely as an electronic complement of the cognate Lewis acids: in fact Lewis bases are capable of enhancing both the electrophilic and nucleophilic character of molecules to which they are bound. This diversity of behavior leads to a remarkable versatility for the catalysis of reactions by Lewis bases.

1,050 citations

Journal ArticleDOI
TL;DR: The synthesis and properties of homopolymers and copolymers of monomers containing inorganic-organic hybrid polyhedral oligomeric silsesquioxane (POSS) structures are described in this article.
Abstract: This review describes the synthesis and properties of homopolymers and copolymers of monomers containing inorganic–organic hybrid polyhedral oligomeric silsesquioxane (POSS) structures. Monomers, such as styryl-POSS, methacrylate-POSS, norbornyl-POSS, vinyl-POSS, epoxy-POSS, and siloxane-POSS, are included. Both monofunctional and multifunctional monomers are included. Thermoplastic and thermoset systems are considered. Thermal, rheological, and dynamic mechanical properties are described. The synthesis of POSS macromers (monomers) is briefly described. POSS chemicals have been used to prepare nanosized designed novel composites with a variety of potential applications. This review, covering 111 references, is descriptive and not designed to be totally comprehensive. However, the major existing reviews of certain subtopics are noted, allowing the reader to gain a general introduction while providing the information to permit more comprehensive coverage.

1,020 citations

Journal ArticleDOI
TL;DR: In this paper, the authors present a review of current theoretical approaches to adsorption phenomena in five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol−gel-derived oxides, and porous heteropolyanion salts.
Abstract: Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films, and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol−gel-derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

722 citations