AppliedChem, Volume 1, Issue 1 (September 2021) – 6 articles

Food quality is a topic of utmost importance as more and more emphasis is placed on quality rather than quantity of products. Previous studies have pointed out the interaction of quality with the harvest year. In this study, 22 Pistacia vera (Greek ‘Aegina’ variety) samples (11 from 2017 and 11 from 2018) were differentiated using Fourier transform infrared spectroscopy (FTIR) and (a) diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and (b) KBr/sample disk techniques. In both years, the pistachios trees’ growing followed standard cultivation methods and similar agronomic conditions. Two chemometric models were developed using partial least squares-discrimination analysis (PLS-DA). DRIFTS proved unable to statistically differentiate the samples (R² = 0.96266, Q² = 0.63152). On the contrary, the disk technique completely differentiated the pistachio samples (R² = 0.99705, Q² = 0.97719). The 1720–1800 cm⁻¹ region mostly contributed to the discrimination. The disk-FTIR chemometric model is fast, robust, economical, and environmentally friendly for determining pistachio matrix quality. Full article

In order to afford the required level of broad-spectrum photoprotection against UV-B and UV-A radiation, sunscreens must contain a combination of UV filters. It is important that any interactions between UV filters do not adversely affect their photostability nor the overall photostability of the sunscreen formulation. In this work, we explore the feasibility of using methyl anthranilate (MA) as an alternative to the photo-unstable UV-A filter, avobenzone. From the in vitro studies presented here, we conclude that MA does not provide sufficient UV-A protection on its own but that it is more photostable in formulation than avobenzone. In addition, we found that both octocrylene (OCR) and ethylhexyl methoxycinnamate (EHMC), two commonly used UV-B filters, can stabilize MA through quenching of its triplet states, as previously reported, which has a demonstrable effect in formulation. In contrast with previously reported observations for mixtures of EHMC and avobenzone, we found no evidence of [2+2] photocycloadditions taking place between EHMC and MA. This work demonstrates how a clear insight into the photophysics and photochemistry of UV filters, as well as the interactions between them, can inform formulation design to predict sunscreen performance. Full article

Chromium plating has excellent corrosion resistance and is widely used in industry. However, it also has a high environmental load. As an alternative, electric Ni-W plating is attracting attention. However, it is not widely used because the stress is high and the film is prone to cracks. Furthermore, although it is necessary to thicken the film to improve the corrosion resistance, there are also problems that the current efficiency is low and the plating time is long. Therefore, we investigate a film with high corrosion resistance by using the jet-flow plating method that enables plating at a high current density. Our results show that the jet-flow plating enables plating of 50 µm, and high corrosion resistance is obtained by randomly generating fine cracks in the film at 20 A·dm⁻². We also found that the stress changed depending on the current density and shape of the crack also changed. Full article

Colorimetric gas detectors have been widely applied in many fields such as environmental sciences, industrial hygiene, process control, forensic science and indoor air quality monitoring. They have a history of about 100 years and include devices such as gas detector tubes and paper-based gas detectors. The sensitivity and selectivity of the colorimetric gas detector are relatively high compared to other types of gas detectors such as semiconductor, catalytic combustion and electrochemical gas detectors. Detection of gas concentration can be performed by the naked eye in some colorimetric gas detectors. These methods do not require an electrical power source and are simple, so they are suitable for field operations. This review introduces the history and provides a general overview of the development in the research of colorimetric gas detectors. Recently, the sensitivity and selectivity of colorimetric gas detectors have improved. New materials such as enzymes or particles with a large surface area have been utilized to improve selectivity and sensitivity. Moreover, new gas detectors without toxic materials have been developed to reduce the environmental load. At present, there is a rapid development of IoT sensors in many industrial fields, which might extend the applications of colorimetric gas detectors in the near future. Full article

Successful eradication or control of prevailing infectious diseases is linked to vaccine efficacy, stability, and distribution. The majority of protein-based vaccines are transported at fridge (2–8 °C) temperatures, cold chain, to retain potency. However, this has been shown to be problematic. Proteins are inherently susceptible to thermal fluctuations, occurring during transportation, causing them to denature. This leads to ineffective vaccines and an increase in vaccine-preventable diseases, especially in low-income countries. Our research utilises silica to preserve vaccines at room temperature, removing the need for cold chain logistics. The methodology is based upon sol–gel chemistry in which soluble silica is employed to encapsulate and ensilicate vaccine proteins. This yields a protein-loaded silica nanoparticle powder which is stored at room temperature and subsequently released using a fast chemical process. We have previously shown that tetanus toxin C fragment (TTCF) ensilication is a diffusion-limited cluster aggregation (DLCA)-based process using time-resolved small-angle x-ray scattering (SAXS). Here, we present our expanded investigation on the modularity of this system to further the understanding of ensilication via time-resolved SAXS. Our results show that variations in the ensilication process could prove useful in the transition from batch to in-flow manufacturing of ensilicated nanoparticles. Full article