It has been demonstrated that a micropatterned surface can decrease the resistance of anion exchange membranes (AEMs) and can induce desirable flow properties in devices, such as mixing. Previously, a model that related the resistance of flat and patterned membranes with the same equivalent thickness was proposed, which used the patterned area and thickness ratio of the features to describe the membrane resistance. Here, we explored the validity of the parallel resistance model for a variety of membrane surface designs and area ratios. We demonstrated that the model can predict the resistance of a wide range of patterned AEMs. We showed that the resistance is independent of the spatial ordering of the design by examining random patterns, which is relevant for applications that require, for example, increased turbulent liquid flow in multilayered devices. Some experimental values of resistance obtained for patterned membranes presented deviations from the model. Scanning electron microscopy (SEM) images of the patterned membranes revealed resolution variations and pattern replication errors due to the stereolithographic process. A geometric correction of the target ratios improved the fit of the modelled data to the experimental values, showing that light bleeding during curing was a source of error. Two additional experimental factors were not accounted for in the model: a distinct interface between the bottom and top layer, and overcuring of the bottom layer during successive steps. These sources of error were investigated by examining the resistance of single and double layered membranes, and single layer membranes with different curing times. The differences obtained in the resistances for control samples demonstrated that both the interface and overcuring influence the resistance of the membrane. The results obtained in this study enlighten the discussion relating membrane surface morphology and transport properties, as well as the optimization of 3D printed membranes using a stereolithography process.

In situ detection of hydrocarbons in water using ATR-FTIR with LLDPE film.

Due to the emergence of sub-10 nm technologies, next generation slurries have continued to increase in complexity to meet stringent device performance demands. Prior to the chemical mechanical planarization (CMP) process, point-of-use filtration (POU) is implemented in order to limit particle aggregates and ultimately decrease surface defects. This study probes the non-covalent interactions at the interface of a fundamental Cu slurry and a polyamide and polypropylene-based membranes. Results indicate that independent of the membrane used, material removal rate (MRR) showed a subtle decrease as a result of filtration (time and ΔP), demonstrating that the synergistic balance between the nanoparticle and slurry additives is disrupted during the filtration process. Corrosion current measurements (Icorr) decreased by at least 85% post-filtration, indicating a rapid adsorption of glycine to the filter membrane. Regardless of the filter membrane, glycine adsorption was further validated using a modified electrochemical quartz crystal nanobalance (EQCN) technique. Since Cu-glycine complexes are integral in controlling MRR, a widely reported method of tracking *OH production was employed. Results show a decrease in the concentration of *OH, which in turn can be correlated to a decrease in the Cu-glycine complexes, altering the overall Cu MRR.