A Super-Amphiphilic 3D Silicone Sponge with High Porosity for the Efficient Adsorption of Various Pollutants

Screening and validation of sponge materials assembled to a sampling device for enrichment and determination of amphetamine drugs in exhaled breath by HPLC-TQ-MS/MS

Exhaled breath aerosol (EBA) analysis of the amphetamine drugs (AMPs) and ephedrine (EPH) has a great potential to monitor illicit drug abuse due to its simple, non-invasive, convenient, and easily accepted sampling. Nevertheless, the extremely low concentration of AMPs and EPH in EBA poses great challenges to instrumental analysis. In this study, a self-designed sampling device equipped with sponge-based material was developed and coupled to high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-TQ-MS/MS) for monitoring of the AMPs and EPH in EBA. Accordingly, the cellulose sponge with high adsorption performance and low expiratory resistance was screened out from multiple commercial sponges, optimized its configuration performance, and assembled to the sampling device, reaching the adsorption rates of 81.6 ± 2.2-98.9 ± 2.5 % for EPH and typical AMPs, including amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine. The combination of HPLC-TQ-MS/MS and the device containing cellulose sponge showed excellent analytical performance, with linearity in the range of 30.0-20000.0 pg/filter (R ≥ 0.9901), low detection limit of 1.6-8.4 pg/filter, and the recoveries of 86.5-94.5 %. The device also exhibited good reusability and applicability for the simulated EBAs at different levels. Furthermore, the proposed method was successfully applied for determination of EPH in volunteers' EBAs, whose contents suggested a good correlation with that in saliva. Kinetic analysis provided insights into the adsorption mechanism, further validating reliability of the method. Overall, the simple, cheap, available, and reusable cellulose sponge assembled to sampling device was advantageous for enriching and monitoring of trace illicit drugs in human EBA.

An In Situ Characterisation Method for 3-D Electrospun Foams

Three-dimensional electrospun foams are emerging in a diversity of applications. However, their characterisation involves procedures to calculate fibre diameter and porosity, which take considerable time. Hence, in this paper, an in situ characterisation method is presented based on signal features of the grounding voltage. These features are combined into the in situ evaluation parameter Sr for each run r. The L9 Taguchi method was utilised to minimise the total number of experiments. Moreover, to prove the accuracy of this method, the traditional post-fabrication analysis was conducted, and the post-fabrication evaluation parameter was retrieved Qr for each run r. The analysis shows that both parameters detected the same experiment run as the optimal one (with an adjusted R2 = 0.84) for polystyrene electrospun foams for two solution concentrations: 15%wv (run 3 with mean S3 = 54.49 and mean Q3 = 0.248) and 20%wv (mean S5 = 2.49 and Q5 = 0.248), respectively. Also, the statistical analysis shows low standard deviations for the optimal and near-optimal runs, proving the method's repeatability. Furthermore, a theoretical explanation is provided for selecting signal features based on the Maxwellian equivalent circuit approach for the electrospun jet. Finally, this fast in situ evaluation method can replace the post-fabrication time-consuming one. It can be used as a fundamental step for an intelligent artificial intelligence tool that predicts optimal foam formation.

Synthesis of Vinyl-Containing Polydimethylsiloxane in An Active Medium

This research deals with the synthesis of copoly(methylvinyl)(dimethyl)siloxanes by the copolycondensation of dimethyldiethoxy- and methylvinyldimethoxysilane in an active medium, followed by thermal condensation in a vacuum. We achieved a range of copolymers exhibiting finely tuned molecular weights spanning between 1500 and 20,000 with regulated functional methylvinylsiloxane units. Analysis of the microstructure showed that the copolymerization predominantly formed products demonstrating a random distribution of units (R~1). However, an increase in the content of vinyl-containing monomers increases the R parameter, indicating an enhanced tendency towards alternating linkages within the copolymer matrix.

Micromotor-in-Sponge Platform for Multicycle Large-Volume Degradation of Organic Pollutants

The presence of organic pollutants in the environment is a global threat to human health and ecosystems due to their bioaccumulation and long-term persistence. Hereby a micromotor-in-sponge concept is presented that aims not only at pollutant removal, but towards an efficient in situ degradation by exploiting the synergy between the sponge hydrophobic nature and the rapid pollutant degradation promoted by the cobalt-ferrite (CFO) micromotors embedded at the sponge's core. Such a platform allows the use of extremely low fuel concentration (0.13% H₂ O₂ ), as well as its reusability and easy recovery. Moreover, the authors demonstrate an efficient multicycle pollutant degradation and treatment of large volumes (1 L in 15 min) by using multiple sponges. Such a fast degradation process is due to the CFO bubble-propulsion motion mechanism, which induces both an enhanced fluid mixing within the sponge and an outward flow that allows a rapid fluid exchange. Also, the magnetic control of the system is demonstrated, guiding the sponge position during the degradation process. The micromotor-in-sponge configuration can be extrapolated to other catalytic micromotors, establishing an alternative platform for an easier implementation and recovery of micromotors in real environmental applications.

Superelastic Clay/Silicone Composite Sponges and Their Applications for Oil/Water Separation and Solar Interfacial Evaporation

3D porous materials are of great interest in many areas of study, but it is still difficult to prepare those with high elasticity and low thermal conductivity via facile methods. Here, superelastic laponite/silicone (LS) composite sponges with low thermal conductivity are prepared via a simple approach. The LS sponges were analyzed by various characterization methods. The content of laponite nanosheets in LS sponges has a great influence on the microstructure, comprehensive mechanical properties, and thermal conductivity. LS sponges feature (i) high mechanical strength, compressibility, and elasticity, (ii) excellent superhydrophobicity/superoleophilicity, and (iii) low thermal conductivity. Consequently, LS sponges could be used for water purification, for example, oil/water separation and solar-driven interfacial evaporation in combination with carbon nanotubes (CNTs). The LS/CNTs solar evaporator has a remarkable evaporation rate of 1.77 kg m^-2 h^-1 for the 3.5 wt % NaCl aqueous solution under 1 kW m^-2 irradiation and high salt resistance. We foresee that this study will promote the development of new 3D porous materials and their applications.