Micro Scalable Graphene Oxide Productions Using Controlled Parameters in Bench Reactor

The detailed study of graphene oxide (GO) synthesis by changing the graphite/oxidizing reagents mass ratios (mG/mROxi), provided GO nanosheets production with good yield, structural quality, and process savings. Three initial samples containing different amounts of graphite (3.0 g, 4.5 g, and 6.0 g) were produced using a bench reactor under strictly controlled conditions to guarantee the process reproducibility. The produced samples were analyzed by Raman spectroscopy, atomic force microscopy (AFM), x-ray diffraction (XDR), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetry (TGA) techniques. The results showed that the major GO product comprised of nanosheets containing between 1–5 layers, with lateral size up to 1.8 µm with high structural quality. Therefore, it was possible to produce different batches of graphene oxide with desirable physicochemical characteristics, keeping the amount of oxidizing reagent unchanged. The use of different proportions (mG/mROxi) is an important strategy that provides to produce GO nanostructures with high structural quality and scale-up, which can be well adapted in medium-sized bench reactor.

SISTEMA ROBÓTICO DE BAIXO CUSTO PARA PREPARAÇÃO DE FILMES POR LAYER-BY-LAYER

LOW-COST ROBOTIC SYSTEM FOR PREPARATION OF LAYER-BY-LAYER FILMS. Layer-by-Layer is an efficient technique for the deposition of thin films used in several devices such as sensors, solar cells, and other systems. A robotic system improves the process reproducibility, be a stand-alone system, and does not demand human participation during the deposition process. On the other hand, the commercially available equipment is expensive. In this work, we present a low-cost robotic system built by using materials commonly found that allows performing several bathing, drying steps and deposition cycles of the substrates necessary for the formation of LbL films. This technical note presents the electronic assembly scheme and the program developed for an experiment. The number of baths, the time necessary for the deposition, and repetitions to result in the formation of the desired film; can be easily modified in this program. The films prepared in this experiment were successfully employed for the preparation of compact layers for perovskite solar cells. Therefore, the equipment can be easily customized to the needs of each research group that uses it.

ELECTROSPUN BIOMATERIALS AND RELATED TECHNOLOGIES

Electrospun Biomaterials and Related Technologies is a multi-contributed book containing review articles from worldwide authors with industry and academic background. This book is aimed to deliver a compiled overview in biomaterials electrospinning, including strategies, relevant technologies, and state-of-the-art research. The editor, Jorge Almodovar, has chemical engineering background with extensive research experiences and focus on engineering of biomimetic materials. The book consists of nine chapters in 282 content pages. Arranged in a concise format, it delivers a comprehensive but not exhaustive reading text. The chapters cover broad range of topics in electrospinning field, including process reproducibility and robustness, fibrous collagen scaffold, cellulose-based biomaterials, biopolymer nanofibres, green electrospinning, electrospun materials for cancer research, nanofibrous nerve conduits, scaffold for retinal tissue engineering, and smart material. These topics are mainly related to biomedical applications, but studies on environmental engineering are also conferred.

Process Dynamics and Control Analysis for Electrospinning Nanofibers

In many emerging, high value electrospinning applications, the diameter distribution of electrospun fibers has important implications for the product’s performance and process reproducibility. However, the current state-of-the-art electrospinning process results in diameter distribution variations, both during a run and run-to-run. To address these problems, a vision-based, open loop system has been developed to better understand the process dynamics. The effects of process parameters on fiber diameter distributions are investigated, process dynamics are identified, and the relation between measurable variables and the resulting fiber diameter distribution is analyzed.

Automation Features Used with the Halide-Cvd Technique at the AT&T-Microelectronics Production Plant in Reading, Pennsylvania

The the Halide-CVD technique is used in both research and development as well as production at AT&T. The unique requirements of the production environment dictate that reactor designs include features to improve reproducibility and maintenance, as well as reduce operator intervention. Features incorporated in the Halide-CVD reactor at AT&T include microprocessor control of valves, mass flow controllers, and furnace temperature setpoints. The unique needs of a production facility, such as process reproducibility, and commonality with standard plant equipment and information systems, will be highlighted.