Bhanu P. S. Chauhan

Hybrid nanomaterials : synthesis, characterization, and applications

Chapter 1. Thermosensitive Core-Shell Microgel Particles as Carrier System for Catalytic Metal Nanoparticles (Professor Matthias Ballauff). Chapter 2. Metal and Metal Oxide Nanostructures on Resin Support (Professor Tarasankar Pal). Chapter 3. Nanocluster Catalysts and Their Practical Utility in Generation of Functionalized Organo-Silicon Polymers (Professor Bhanu P. S. Chauhan). Chapter 4. Design and Synthesis of Nano-Hybrid Systems Based on Silicon-Oxygen Bond (Professor Yusuke Kawakami). Chapter 5. Nanocrystalline Magnesium Oxide for Asymmetric Organic Reactions (Dr. M. Lakshmi Kantam). Chapter 6. Boron-Based Hybrid Nanostructures: Novel Applications of Modern Materials (Professor Narayan S. Hosmane). Chapter 7. The Exploration of Biomedical Multimodality in Small Solid Core Nanoparticles (Professor Marc Walters). Chapter 8. A Survey of Interactions of Gold Nanoparticles with Common Human Blood Plasma Proteins (Professor Alamgir Karim). Chapter 9. Genetically Modified Collagen-Like Triple Helix Peptide as Biomimetric Template (Professor Hiroshi Matsui). Chapter 10. Polydiacetylene-Containing Liposomes as Sensory Materials (Professor Sanku Mallik). Chapter 11. Block-Copolymer-Templated Synthesis of Ordered Silicas with Closed Mesopores (Professor Michal Kruk). Chapter 12. Organic Inorganic Hybrid Nanomaterials: Organization, Functionalization and Potential Applications in Environmental Domain (Professor Ahmad Mehdi).

First Example of Monomeric Hydrosilane Stabilized Redispersible Silver Nanoparticles

The direct production of silver nanoparticles in organic media is achieved via a simple one pot protocol using long chain hydrosilanes both as reducing and stabilizing agents. This synthetic strategy leads to highly efficient production of stable yet reactive silver nanoparticles. This synthesis is unique in terms of stabilization mechanism, where a very weak passivation is used to produce dispersible but highly active nanoparticles. The effect of hydrosilane alkyl chain length on the growth mechanism, reactivity, dispersibility and stability of the nanoparticles are also investigated.

Controlled Fabrication of Self-Assembled Arrays of Silver Nanoparticles

A simple one pot, highly efficient method to produce self-assembled arrays of functional silver nanoparticles is presented. In this strategy, a combination of tris[3-(trimethoxysilyl)propyl] isocyanurate (TTPI) and trioctylamine (TOA) play the dual role of reducing and stabilizing agents. In situ self-polymerization of TTPI, after attachment with self-assembled nanoparticles provides unique silicon nucleated soluble nanocomposites.

New Avenues, New Outcomes: Nanoparticle Catalysis for Polymer Makeovers

In this chapter, nanocluster catalyzed modifications of organic and silicon based polymers are described. The tailoring of the polymeric templates was carried out under mild conditions and led to hybrid polymers in quantitative yields. Detailed characterization studies indicated that the integrity of the polymeric templates was not compromised during the functionalization process. The nanoparticle catalysis was found to be quite effective and highly selective. In most cases exclusive β-hydrosilylation products were obtained without any rearrangement or isomerization reactions. Detailed characterization and property profiling of the new hybrid polymers is also presented.

Highly Efficient Recyclable Sol Gel Polymer Catalyzed One Pot Difunctionalization of Alkynes

Amino-bridged gel polymer P1 was discovered to catalyze alkyne halo-functionalization in excellent yields, regioselectivity, functional group compatibility, and recyclability. We have observed that both aromatic and aliphatic alkynes can be converted to α,α-dihalogenated ketones in the presence of polymer P1 under metal-free conditions at room temperature within a short reaction time.

Generation of Zerovalent Metal Core Nanoparticles Using n-(2-aminoethyl)-3-aminosilanetriol.

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.