Microfluidic Synthesis and Analysis of Bioinspired Structures Based on CaCO3 for Potential Applications as Drug Delivery Carriers

Naturally inspired biomaterials such as calcium carbonate, produced in biological systems under specific conditions, exhibit superior properties that are difficult to reproduce in a laboratory. The emergence of microfluidic technologies provides an effective approach for the synthesis of such materials, which increases the interest of researchers in the creation and investigation of crystallization processes. Besides accurate tuning of the synthesis parameters, microfluidic technologies also enable an analysis of the process in situ with a range of methods. Understanding the mechanisms behind the microfluidic biomineralization processes could open a venue for new strategies in the development of advanced materials. In this review, we summarize recent advances in microfluidic synthesis and analysis of CaCO3-based bioinspired nano- and microparticles as well as core-shell structures on its basis. Particular attention is given to the application of calcium carbonate particles for drug delivery.

Developments of crystal structures and photoluminescence properties of Sr0.85Eu0.15Al12O19 green phosphors using different synthesis parameters

First, a solid-state reaction method was used to synthesize a [Formula: see text] phosphor at 1250[Formula: see text]C–1400[Formula: see text]C for 1 h, and its crystal structures and photoluminescence properties were investigated as a function of synthesis temperature. When the furnace reached the synthesis temperature, the 5% [Formula: see text] reduction atmosphere was infused and the reduction atmosphere was removed as the temperature was dropped to 800[Formula: see text]C. When 1200[Formula: see text]C was used as the synthesis temperature, the [Formula: see text], [Formula: see text], and [Formula: see text] phases co-existed; only one weak emission peak was observed in the photoluminescence excitation (PLE) spectra, and two weak emission peaks were observed in the photoluminescence emission (PL) spectra. When the [Formula: see text] phosphors were synthesized at a temperature higher than 1200[Formula: see text]C, the diffraction intensities of [Formula: see text], [Formula: see text], and [Formula: see text] phases were almost unchanged, but the crystal sizes of [Formula: see text] powders increased. For [Formula: see text] phosphors, PLE spectra had one broad exciting band with two centered wavelengths of 317 and 365 nm, and PL spectra had one emission band with one centered wavelength of 513 nm. As the synthesis temperature rose, the emission intensities of PLE and PL spectra increased. Second, we show that the removed temperature of reduction atmosphere of [Formula: see text] phosphors had an apparent effect on their emission properties of PLE and PL spectra.

Structural properties of TiO2-SnO2 thin films prepared by new pyrolysis solid-phase method

Nanoscale TiO2-SnO2 films with the Ti:Sn ratio 1:99, 3:97 and 5:95 mol%, respectively, were obtained by solid-phase low-temperature pyrolysis method. The synthesized materials were studied by X-ray phase analysis and scanning electron microscopy (SEM) analysis. Regardless of the modified agents’ concentration, the structure of cassiterite was observed for all synthesized materials. When studying the effect of synthesis parameters on the materials properties, it was shown that both an increase in the Ti4+ concentration and in the calcination temperature leads to an increase in the particle size.

Synthesis and applications of zinc oxide for removal of various pollutants: A review

The versatility of zinc oxide applications in the removal of various pollutants has attracted a wide interest of researchers in the past decade. Numerous studies reported on zinc oxide synthesis pathways and resulting nanoparticle morphologies, applications, formation mechanisms and synthesis parameters. In this review the reported zinc oxide synthesis methods are classified into chemical, physical and biological routes; they are evaluated in terms of the required chemicals, synthesis conditions and the resulting morphologies and properties of zinc oxide. The chemical route of zinc oxide synthesis covers precipitation, micro-emulsion, solgel, solvothermal and hydrothermal paths. The physical route includes laser ablation and high energy ball milling, while the biological route covers plant extracts and microbe mediated synthesis. The mechanisms of zinc oxide formation of the mentioned routes are based on one or more of the following processes: particle nucleation, diffusional growth, Ostwald ripening, particle aggregation and sintering. The most influencing synthesis parameters overall are temperature, drying duration and additives’ effect. Higher temperatures (>200°C) commonly produce larger particles of zinc oxide (> 80 nm); the prolong duration (> 60 min) often results in the agglomeration and sintering of zinc oxide particles. However, additives may mitigate agglomeration extent. Overall, the chemical route is more preferable due to its flexibility that is also linked to the greater variability of zinc oxide particles. The physical method produces more consistent zinc oxide particles but requires higher energy inputs. The biological method is very promising and associated with low chemicals consumptions and good quality of zinc oxide.