Investigation on Variables Contributing to the Synthesis of C-S-H/PCE Nanocomposites by Co-Precipitation Method

The usage of nanoscale calcium silicate hydrate (nano C-S-H) proved to have an excellent promotion effect on the early performance of concrete as nano C-S-H with ultra-fine particle size can act as seeding for cement hydration. Therefore, it is of importance to tune the particle size during the synthesis process of nano C-S-H. In this paper, the influence of several variables of the particle size distribution (PSD) of nano C-S-H synthesized by chemical co-precipitation method with the aid of polycarboxylate (PCE) was studied by orthogonal experimental design. In addition, the composition, microstructure, and morphology of the C-S-H/PCE nanocomposites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The results showed that the concentration of reactants had a significant impact on the PSD of C-S-H/PCE nanocomposites, followed by the dosage of dispersant. Ultrasonic treatment was effective in breaking the C-S-H/PCE aggregates with unstable agglomeration structures. The change in synthetic variables had a negligible effect on the composition of the C-S-H/PCE nanocomposites but had a significant influence on the crystallinity and morphology of the composites.

Thermo-Mechanical Dry Coating as Dry Coating Process is for Pharmaceuticals

The manuscript aims to provide glimpse on updated information relating thermo-mechanical dry coating processes (TMDCP) suiting in modifying surface attributes of fine and ultra-fine particle (FiUlFiP). FiUlFiPs are the integral component of pharmaceutical processes. They exhibit complex and queer properties, are conferred mostly from their surface attributes colligated with their higher surface area. Particle engineering technocrats extensively working for modifying surface & surface attributes of FiUlFiPs. These efforts are to find their worthy applications & new functionalities. Among available diverse particle engineering technologies/ process, TMDCP, a dry coating process (DCP), advocated being worthy and efficient. The TMDCP finds multidisciplinary applications, mostly in drug development & drug delivery. Said DCP involves fixing and/or attaching coating material (CoM) as particles herein synonym guest particle (GP) onto core/substrate particle (CSP) herein synonym host particle (HP). Attaching/ fixing the GPs onto HPs, in TMDCP, involve their mechanical and/or thermal interactions. Scientific literatures are evidencing diverse techniques and/or process, basing on discussed interactions. Amongst them novel techniques/ processes are Hybridization, Magnetically assisted impaction coating process (MAICP), Mechanofusion, Theta-composer, and high shear compaction. In this area diverse devices/ equipments are prevailing in market. Important are Hybridizer, Magnetically assisted impaction coater (MAIC), Theta-composer, Mechanofusion, Quadro Comil®, Cyclomix®, and many others. Attempt of this article is to discuss and present their method of working, working principle, applicability, limitations, and benefits. Contained information might be beneficial for professionals of pharmaceutical and allied field. Keywords: dry coating, equipment, particles, processes, thermo-mechanical.

Recovery of K2SO4 and Separation of SiO2/Al2O3 from Brown Corundum Fly Ash

Brown corundum fly ash (BCFA), which is the collected ash in brown corundum production, has received lots of environmental concerns due to its ultra-fine particle size and complex composition. Aiming to recycle the major elements including K, Al and Si from BCFA environmentally, this work proposed a simple and non-pollution process to utilize BCFA by water leaching, size screening and solution evaporation. The influences of water leaching conditions including leaching temperature, time and liquid-to-solid ratio was considered to optimize the K2SO4 recovery efficiency. Results show that the potassium sulfate content of the product is 75.7% after water leaching at 60 °C for 15 min with the liquid–solid ratio of 20:1. The wet screening and size separation with a 1 μm sieve can separate and enrich aluminum and silicon significantly. The aluminum-rich product is composed of 54.65% of alumina and 11.04% silica, with the alumina and silica ratio (A/S) of 4.95. The silicon-rich product with a particle size of less than 1 μm has a silica content of 57.57% can be used as high-value micro-sphere silica. The research results revealed in this work offers a potential and environmentally industrial treatment technique for the BCFA.

Biogenic Synthesis of Gold Nanoparticles from Aspartic Acid - A Preliminary Study

A nanoparticle is an ultra-fine particle with at least one dimension between 1-100 nanometers (nm). Metallic nanoparticles are considered as most promising as they contain remarkable antibacterial properties. Gold nanoparticles are of high importance in research. Aspartic acid is an alpha amino acid and contains one amino group and one carboxylic group. The aim of the current study was to bio synthesize gold nanoparticles using aspartic acid. Gold Chloride (AuCl3) and Aspartic acid (C₄H₇NO₄) were used for the study. AuCL3 solution (0.266 M) was slowly added to 250 aspartic acid with stirring at 45°C. The mixture of the solutions was kept in a long-necked borosilicate flask and continuously stirred on a magnetic stirrer. The formation of gold nanoparticles was confirmed by the change of the colorless solution to a reddish hue. Characterization of the newly formed nanoparticles was then done. After approximately 9 hour incubation and intermittent stirring with a magnetic stirrer the solution color changed from colorless to a reddish hue, which indicated the formation of AuNPs. The spectrometric reading was recorded at a scanning range of 400–700 nm. AuNPs nanoparticles at 24 hours showed an increased intensity and a Surface Plasmon Resonance (SPR) band at 575 nm. The gold nanoparticles by Transmission electron microscopy were confirmed to be spherical in shape and of 20 nm. A simple and efficient method for the synthesis of AuNPs from the aspartic acid was demonstrated. Nano particles were formed in approx. 9 hours with peak absorbance at 24 hours at 575nm. The synthesized nanoparticles were spherical in shape, with an average size of 20 nm. The synthesized nanoparticles showed excellent plasmon resonance and optical properties.