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Improving the sustainability of energy-intensive materials, such as silicone, can be achieved through the incorporation of fillers, reducing the total amount of silicone needed. In this context, the incorporation of biodiesel-originating glycerol into commercially available hydrophobic polydimethylsiloxane (PDMS) pre-polymer has not only exhibited cost-effectiveness but also demonstrates a reduction of the environmental impact of silicone elastomers and adhesives [1]. Due to the ability of glycerol to dissolve and release active ingredients, the two-phase glycerol-silicone elastomers have potential applications in the skin care industry [2]. In this study, we propose a biocompatible skin-cure silicone-glycerol patch with active ingredients that ensure a comfortable and gentle adaptation to the skin. The efficacy of the glycerol-silicone skin cure formulation in improving skin properties was demonstrated.

The exploitation of fillers to reduce the environmental impact of silicone elastomers and adhesives always seem to introduce either rigidity or reduced performance of the silicone products. Counterintuitively, glycerol can be introduced into silicone and results in interesting properties of the resulting silicone elastomers and adhesives, with significantly improved moisture handling properties as the main advantage, and simultaneously not altering the mechanical and adhesive properties. Furthermore, introducing glycerol in significant amounts can reduce the environmental impact of up to 40% of the silicone product. The recently developed silicone-based composite consisting of a silicone matrix with discrete compartments of liquids has been shown to hold great potential in various applications and promises to become a platform for creating multiple functional smart materials. It is prepared by a patented glycerol-in-PDMS emulsion, which is very stable for a broad range of concentrations. The glycerol allows for the incorporation of drugs and actives and can therefore be used for active wound care adhesives or vehicles for skin therapeutics.

This study is about rescheduling freight trains to reduce the eff ects of major interruptions. In this paper, we consider that the interruption is an unexpected marshallingyard closure. We develop a macroscopic Mixed-Integer Linear Programming (MILP)model to reschedule railway timetables. One important principle is that we simultaneously reschedule several trains, instead of one-by-one. Furthermore, we consider arescheduling strategy of letting trains wait on the way when the destination yard havea closure. The model considers stopping restrictions and the capacity of each segmentand station. The order of the trains aff ected by the interruption is not fi xed. We presentexperimental results of three diff erent cases, which are all based on artifi cial data.

Dielectric elastomers (DEs) exhibit high obtainable actuation speeds, large strains and high work densities, showing great potential for actuator applications such as flat screen loud speakers, lightweight morphing structures and prosthetics.[1] To date, varying configurations for dielectric elastomer actuators (DEAs) have been studied, including planar, tube, roll, extender, diaphragm, and bender.[2] Tube DEA consists of a thinwalled cylindrical tube of a dielectric elastomer, having two compliant electrodes on the internal and external lateral surfaces. By applying a voltage between the compliant electrodes, the interposed tube wall is squeezed, causing an axial elongation. Tube DEAs are potential candidates for the realisation of “artificial muscles” owing to their linear (along a line) actuation capabilities.[3] Electroactive fiber actuators include bundles of tube DEAs, which produce a very strong actuation force as a result of the accumulation of individual force generated by each tube DEA. Even if a fraction of the fibers in a bundle fail, the electroactive fiber actuator will in most cases continue to operate. Furthermore, because electroactive fibers have small thickness sometimes on the order of a few micrometers, actuation voltages less than 100 V can be used.[4] In this work, polydimethylsiloxane (PDMS) fiber is prepared by means of wet spinning method using photocurable thiol-ene reaction between the carbon-based sulfhydryl (R-SH) group and alkene (C=C) group in the thiol-ene-based PDMS resins to form an alkyl sulfide. The developed PDMS fiber shows improved mechanical properties compared to the planar film. The resulting fiber DEA exhibits larger and more linear deformation when working in multiple cyclic actuation tests. This work provides wider avenues for creating active soft matter with complex architectures to enable fast programmable actuation for a myriad of applications including soft actuators and robots.

A controllable magnetochromic elastomer is developed by dissolving magnetic nanoparticles (MNPs) in poly(ethylene glycol)-200 (PEG-200) and emulsifying the solution in polydimethylsiloxane (PDMS) using a high-shear Speedmixer. The MNPs are aligned in order along the direction of the externally applied magnetic field, causing the material to become transparent and realizing a switch on/off function. Both particle size and size distribution were observed to affect magnetochromic response, and use of an ultrasonication bath was shown to prohibit MNP agglomerations. In addition, the surfactant surface-modified MNPs synthesized via co-precipitation were shown to possess both a smaller primary size and a narrower size distribution compared to non-treated commercial MNPs, leading to improved MNP dispersion stability in PEG-200. The optimized silicone elastomer—with 40 parts per hundred rubber (phr) PEG-200 and 3 wt% MNPs modified by citric acid surfactant—exhibits instantaneous and reversible color change when exposed to an external magnetic field. The color changing efficiency and fast response time of the magnetochromic elastomer developed here are suited to a variety of color tuning applications: e.g., bio-sensors and anticounterfeiting labels.

Introduction: There are several cannabidiol (CBD) transdermal patches available on the market. However, none are FDA-approved. Furthermore, not much evidence has been published about CBD release and skin permeation from such patches, so the effectiveness and reliability remain unclear. Objectives: We aimed to develop a method to determine the in vitro release and skin permeation of CBD from transdermal patches using Franz cell diffusion in combination with quantitative 1H-NMR (qNMR). Materials and Methods: The study was conducted on CBD patches with known CBD content and six different commercially available or market-ready CBD patches using a Franz cell with a Strat-M™ membrane and with samples taken directly from the transdermal patch for qNMR analysis. Results: The use of qNMR yielded an average recovery of 100% ± 7% when samples with known CBD content were tested. Results from the testing of six commercially available patches indicated that five out of six patches did not contain the CBD amount stated by the manufacturer according to a ± 10% variance margin, of which four patches were under-labeled and one was over-labeled. The release rate of patches was determined, and significant differences between the patches were shown. Maximum release of CBD was calculated to occur after 39 to 70 h. Conclusion: The established method was proven to be a reliable means of determining the quantity and release of CBD from transdermal patches and can be used to verify CBD content and release rate in transdermal patches.

Low-energy (80-300 keV) electron beam accelerators are gaining in importance in the radiation processing industry due to their ease of use and wide range of applications (e.g. product surface sterilizations or polymer curing and cross-linking). Due to their very low penetration depth (tens to hundreds of microns), currently used film dosimeters exhibit dose gradients over their thickness and do not resolve the dose response in the first microns of the irradiated material. Hence, the surface dose, defined as the dose in the first micron D-mu, cannot be measured directly. This study presents a polymer material as a dosimeter candidate for high-dose low-energy electron beam irradiations. The readout of the dose-dependent fluorescence intensity, originating from a pararosaniline dye reaction when irradiated, is measured using fluorescence microscopy. So far, no in-depth characterization of the material has been performed, leaving the stability and fluorescence properties of the material not fully optimized. We describe the improvements in polymer composition and the fabrication method, and characterize the material properties in terms of the thermal stability, glass transition temperature, refractive index, hardness, rheological behavior, and water affinity. All of these create a complex set of requirements a polymer needs to fulfill to become an effective dosimeter when measuring using confocal microscopy. The fluorescence readout procedure will be addressed in further studies.