The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications i...

http://pubs.acs.org/doi/pdfplus/10.1021/acs.chemrev.5b00482

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

In the past few years, continuous-flow reactors with channel dimensions in the micro- or millimeter region have found widespread application in organic synthesis. The characteristic properties of these reactors are their exceptionally fast heat and mass transfer. In microstructured devices of this type, virtually instantaneous mixing can be achieved for all but the fastest reactions. Similarly, the accumulation of heat, formation of hot spots, and dangers of thermal runaways can be prevented. As a result of the small reactor volumes, the overall safety of the process is significantly improved, even when harsh reaction conditions are used. Thus, microreactor technology offers a unique way to perform ultrafast, exothermic reactions, and allows the execution of reactions which proceed via highly unstable or even explosive intermediates. This Review discusses recent literature examples of continuous-flow organic synthesis where hazardous reactions or extreme process windows have been employed, with a focus on applications of relevance to the preparation of pharmaceuticals.

Continuous‐Flow Technology—A Tool for the Safe Manufacturing of Active Pharmaceutical Ingredients

The successes and failures of past research in the development of microfluidic reactors for chemical synthesis are highlighted. Current roadblocks are assessed and a series of challenges for the future of this area are identified.

/pdf/the-past-present-and-potential-for-microfluidic-reactor-30n6i6acaz.pdf

The past, present and potential for microfluidic reactor technology in chemical synthesis

In recent years, tools for the development of new drugs have been dramatically improved. These include genomic and proteomic research, numerous biophysical methods, combinatorial chemistry and screening technologies. In addition, early ADMET studies are employed in order to significantly reduce the failure rate in the development of drug candidates. As a consequence, the lead finding, lead optimization and development process has gained marked enhancement in speed and efficiency. In parallel to this development, major pharma companies are increasingly outsourcing many components of drug discovery research to biotech companies. All these measures are designed to address the need for a faster time to market. New screening methodologies have contributed significantly to the efficiency of the drug discovery process. The conventional screening of single compounds or compound libraries has been dramatically accelerated by high throughput screening methods. In addition, in silico screening methods allow the evaluation of virtual compounds. A wide range of new lead finding and lead optimization opportunities result from novel screening methods by NMR, which are the topic of this review article.

Drug Discovery Today

In recent years, there has been a great deal of interest in the preparation and application of nanoparticles for cancer therapy. Gold nanoparticles are especially suited to thermal destruction of cancer due to their ease of surface functionalization and photothermal heating ability. Here, we review recent progress in gold nanoparticle-mediated thermal cancer therapies. We begin with an introduction to the properties of gold nanoparticles and heat-generating mechanisms which have been established. The pioneering work in photothermal therapy is discussed along with the effects of photothermal heating on cells in vitro. Additionally, radiofrequency-mediated thermal therapy is reviewed. We focus our discussion on the developments and progress in nanoparticle design for photothermal cancer therapy since 2010. This includes in vitro and in vivo studies and the recent progression of gold nanoparticle photothermal therapy toward clinical cancer treatment.

Recent Progress in Cancer Thermal Therapy Using Gold Nanoparticles

The formation of gas bubbles and their subsequent rise due to buoyancy are very important fundamental phenomena that contribute significantly to the hydrodynamics in gas−liquid reactors. The rise o...

Bubble Formation and Bubble Rise Velocity in Gas−Liquid Systems: A Review

Metal oxide nanoparticles are an important class of nanomaterials that have found several applications in science and technology. Through wet chemical synthesis, it is possible to achieve selective surface structures, phases, shapes, and sizes of metal oxide nanoparticles, leading to a set of desired properties. Wet chemical synthesis routes allow fine tuning of the reaction conditions (temperature, concentration of substrate, additives or surfactants, pH, etc.) to afford the desired nanomaterials. In this review article, we highlight recent developments in the wet chemical synthesis of metal oxide nanoparticles to provide great control over the quality of the obtained nanomaterials. The review critically evaluates the different wet chemical methods for scalable production of metal oxide nanoparticles to satisfy the growing industrial demand for nanomaterials. Special attention is paid to continuous flow synthesis of metal oxide nanoparticles.

Wet chemical synthesis of metal oxide nanoparticles: a review

Segmented flow is often used in the synthesis of nanomaterials to achieve narrow particle size distribution. The narrowness of the distribution is commonly attributed to the reduced dispersion associated with segmented flows. On the basis of the analysis of flow fields and the resulting particle size distribution, we demonstrate that it is the slip velocity between the two fluids and internal mixing in the continuous-phase slugs that govern the nature of the particle size distribution. The reduction in the axial dispersion has less impact on particle growth and hence on the particle size distribution. Synthesis of gold nanoparticles from HAuCl4 with rapid reduction by NaBH4 serves as a model system. Rapid reduction yields gold nuclei, which grow by agglomeration, and it is controlled by the interaction of the nuclei with local flow. Thus, the difference in the physical properties of the two phases and the inlet flow rates ultimately control the particle growth. Hence, a careful choice of continuous and di...

Size-Controlled Flow Synthesis of Gold Nanoparticles Using a Segmented Flow Microfluidic Platform

Coherent flow structures in bubble column reactors

This review highlights the state of the art in the field of continuous flow nitration with miniaturized devices. Although nitration has been one of the oldest and most important unit reactions, the advent of miniaturized devices has paved the way for new opportunities to reconsider the conventional approach for exothermic and selectivity sensitive nitration reactions. Four different approaches to flow nitration with microreactors are presented herein and discussed in view of their advantages, limitations and applicability of the information towards scale-up. Selected recent patents that disclose scale-up methodologies for continuous flow nitration are also briefly reviewed.

https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-10-38.pdf

Amol A. Kulkarni

Papers

Bubble Formation and Bubble Rise Velocity in Gas−Liquid Systems: A Review

Wet chemical synthesis of metal oxide nanoparticles: a review

Size-Controlled Flow Synthesis of Gold Nanoparticles Using a Segmented Flow Microfluidic Platform

Coherent flow structures in bubble column reactors

Continuous flow nitration in miniaturized devices.