Effect of doping atoms in the surface morphology of dense palladium-based diffusion membrane-filters

Atomic force microscopy (AFM) and high-precision scanning electron microscopy methods were used to study the morphology of the surface of diffusion filter-membranes Pd-Pb. Analysis of the AFM microscopy data and microelectronic photographs showed the individual features of the formation of the membrane alloy’s surface topology. The predisposition of the alloy to cavitation was revealed both in the technological process of manufacturing filter-membranes and under exposure to hydrogen.

Surfactant-free production of biomimetic artificial cells using PDMS-based microfluidics

Microfluidic-based production of cellular mimics (e.g. giant vesicles) presents a paradigm-shift in the development of artificial cells. While encapsulation rates are high and vesicles are mono-disperse compared to swelling-based techniques, current microfluidic emulsion-based methods heavily rely on the addition of additives such as surfactants, glycerol and even ethanol to produce stable vesicles. In this work, we present a microfluidic platform designed for the production of cellular mimics in the form of giant unilamellar vesicles (GUVs). Our PDMS-based device comprises a double cross-junction and a serpentine-shaped shear inducing module to produce surfactant-free and additive-free monodisperse biomimetic GUVs. Vesicles can be made with neutral and charged lipids in physiological buffers and, unlike previous works, it is possible to produce them with pure water both inside and outside. By not employing surfactants such as block co-polymers, additives like glycerol, and long-chain poly-vinyl alcohol that are known to alter the properties of lipid membranes, the vesicles are rendered truly biomimetic. The membrane functionality and stability are validated by lipid diffusion, membrane protein incorporation, and leakage assays. To demonstrate the usability of the GUVs using this method, various macromolecules such as DNA, smaller liposomes, mammalian cells and even microspheres are encapsulated within the GUVs.

A Reversible Spectrophotometric Method Based on a Coupled Microfluidic Chip for Highly Selective Ammonium Detection

A coupled chip aiming at economical and highly selective ammonium detection was fabricated. It consisted of a reaction chip, a gas-diffusion chip, and a detection chip. Zinc tetraphenylporphyrin dyed on the cation-exchange resin microbeads was used as the indicating material to avoid excess consumption for its reversibility. PDMS was selected as the material of the gas-diffusion membrane. A portable spectrometer was applied for spectrum analysis. By analysis of spectrum change, the high selectivity was confirmed because no component had interference on detection effect. Good performance was shown for all the tested concentrations (0.2–50 mg·L−1). The stability and reversibility were also judged by the spectrum data obtained from the indicating process and the recovering process. Finally, real samples containing ammonium were tested and the results were compared to those came from a standard method to confirm the accuracy of our method.

Factors affecting performance and functional stratification of membrane-aerated biofilms with a counter-diffusion configuration

Biofilm thickness is a key factor affecting structural and functional stratification of community in counter-diffusion membrane-aerated biofilms (MABs) with the simultaneous degradation of acetonitrile, and nitrification and denitrification.