Soiling can lead to severe performance losses of photovoltaic (PV) plants. Within this study, three different anti-soiling coatings (ASC) were applied to three different commercial, solar-grade rolled glasses with different surface structures. Laboratory soiling experiments were performed including wind simulation and a novel rotational force test to assess the influence of different surface structures of the glass substrate on the anti-soiling performance of the coatings. A detailed microscopic evaluation indicates a consistent ranking of the ASC with regard to particle resuspension behavior for both test methods and all substrates. Furthermore, the rotational force test yields a quantitative measure of the median force needed for particle removal from the respective coating, which is independent of the glass substrate surface morphology.

In this study, Mg-substituted tricalcium phosphate (Mg-TCP) nanoparticles were synthesized by hydrothermal reactions of Mg-calcite mesocrystals from echinoderm skeletons. Following the biomineralization of echinoderms, Mg-calcite powder was synthesized via the solid-state transition of Mg-amorphous calcium carbonate prepared by a wet-chemical precipitation method, which can also be used to fabricate Mg-TCP. We illustrated that Mg-calcite with a certain level of Mg substitution led to the formation of Mg-TCP through the ion-exchange reactions in the hydrothermal system. Therefore, this study provides a new pathway for the synthesis of Mg-TCP nanoparticles.

The practical realization of rechargeable organic batteries is stalled by their low electron conductivity, which limits the organic-active material content in the electrode composite and results in a low net electrode energy density. Additionally, the dissolution of active materials into the electrolyte causes a short cycle life. In this study, a conductive polymer mixture, poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate, containing a small amount of sugar alcohol was used as the binder and separator in a rechargeable organic battery. Consequently, the active material content was increased up to 80 wt%, and the cycle life was extended.

The authors report on 7Li, 19F, and 1H pulsed field gradient NMR measurements of 26 organosilyl nitrile solvent-based electrolytes of either lithium bis(trifluorosulfonyl)imide (LiTFSI) or lithium hexafluorophosphate. Lithium transport numbers (as high as 0.50) were measured and are highest in the LiTFSI electrolytes. The authors also report on solvent blend electrolytes of fluoroorganosilyl (FOS) nitrile solvent mixed with ethylene carbonate (EC) and diethyl carbonate. Solvent diffusion measurements on an electrolyte with 6% FOS suggest both the FOS and EC solvate the lithium cation. By comparing lithium transport and transference numbers, the authors find less ion pairing in FOS nitrile carbonate blend electrolytes and difluoroorganosilyl nitrile electrolytes.

${\rm Au}_{25}\lpar {{\rm C}_6{\rm H}_{14}{\rm S}} \rpar_{18}{}^-$ icosahedron and [Au25(PPh)10(C6H14S)5Cl2]2+ bi-icosahedron clusters were synthesized. Ligand exchange reactions were carried out with a new coumarin-derived fluorophore (Cou-SH) to label both clusters. Labeled and unlabeled Au25 were compared and the changes in the electronic structure were determined. The labeled clusters showed marked changes in electronic states, as evidenced by the quenching in the UV region and enhancement in the near infrared. The quantum yield from Cou-SH decreased and the quantum yield from the labeled Au25 increased. Second, the authors observed changes in the electrochemical band gap.

The rise of additive manufacturing (AM) has enabled the rapid production of complex part geometries across multiple material domains. To date, however, AM of inorganic semiconductor materials has not been fully realized due to the difficulty of forming single-crystal materials with traditional AM processes. Here, we demonstrate a novel semiconductor synthesis method using a combination of liquid and gas precursors to additively print gallium nitride. Growth rates of 1–2 µm/min are demonstrated in printed regions while maintaining epitaxial alignment with the substrate. We also outline critical variables for the future development, improvement, and implementation of the proposed process.

In the past decades, efforts have been made to couple nanoindentation with resistive measurements in order to monitor the real-time contact area, as an alternative to the use of traditional analytical models. In this work, a novel and efficient stand-alone method is proposed to compute the contact area using resistive-nanoindentation of noble metals (bulk or thin films). This method relies on three steps: tip shape measurement, set-up calibration, application to the sample to be characterized. The procedure is applied to nanoindentation tests on a sample with film-on-elastic-substrate rheology and is successfully validated against experimental measurements of the contact area.

Polymeric electrolytes have attracted recent research interest because they offer the advantages of being safe and non-flammable, having no dendrite formation, and having no possibility of leakage. The incorporation of synthetic polymers to gel electrolytes has numerous disadvantages: for instance, the required preparation time for creating gel electrolytes from synthetic polymers is dubious and lengthy. Additionally, the conventional pristine polymer gel electrolyte layer has been reported to have low ionic conductivity. This work is focused on preparing a thin flexible gel electrolyte layer by using a naturally occurring wood-based nanofiber cellulose (NFC) hydrogel, to overcome the energy and time consumption of conventional processes. In addition, we use polyvinyl alcohol (PVA) as an additive to the NFC hydrogel in controlled amounts to fabricate a stable thin gel electrolyte layer. By using x-ray diffraction, optical microscopy, and Fourier transform infrared spectra studies, we were able to further our understanding of the microstructure of the films: i.e., the penetration and cross-linking (changes in the bonding structures) of semi-crystalline PVA and hydrogel to form a flexible gel electrolyte layer. The NFC hydrogel-PVA films resulted in much higher ionic conductivity values when compared to other existing pristine polymer electrolytes. The addition of KOH to the NFC hydrogel-PVA further enhanced the ionic conductivity. The best ionic conductivity recorded was 75 mS/cm for films with thickness in the range of 200–350 µm, which is comparable to the highest reported ionic conductivity values of gel electrolytes.

Powerful synergies between phosphonate, zinc oxide, and acrylamido-tert-butyl-sulfonate (ATBS) copolymer chemical additives render superior performance in a high-temperature retarder system for oil well grade Portland cement. The phosphonate retarder and ATBS-based retarders establish a two-tiered strength development where amorphous C-S-H converts to crystalline dicalcium silicate hydrate (C2SH) in the first (low compressive strength) tier prior to the reaction of Portlandite with quartz. The three additive retarder system can be tuned with nanosilica to eliminate the two-tiered strength development effect leading to a smooth transition from the cement in the slurry form directly to its highest compressive strength.

The strength of single-crystalline nanoscale metals is controlled by dislocation nucleation from free surfaces. Surface properties such as crystallographic orientation, surface stress, and surface diffusion have been proposed as key parameters that control dislocation surface nucleation, but have not been confirmed experimentally. To investigate the influence of surface parameters, in situ scanning electron microscope mechanical testing is used to compress defect-free Ag and Cu nanocubes that are passivated with organic surfactants in order to tune their surface properties. Comparison between passivated nanocubes indicates that yield strength may depend on surfactant binding energy, but is also dependent on intrinsic material properties.

Magnetic nanoparticles have many potential applications in therapeutics and drug delivery. Heating by magnetic nanoparticles for hyperthermia application has gained tremendous popularity as a non-invasive treatment for tumor ablation. The heating effect of magnetic nanoparticles at different concentrations (1–10 wt%) in the fluid is investigated by varying the alternating magnetic field (60–260 Oe). The observed temperature rise (ΔT) shows an unusual increase with applied field in a higher nanoparticle concentration. In contrast to the previous model, the present study shows that temperature rise is more rapid in the higher particle concentration (~10 wt%) and low applied field (<125 Oe), and ΔT varies as H3/2 instead of H2.

The authors prepared a micro-structured, thermosensitive hydrogel with N-isopropylacrylamide microgels with a lower critical solution temperature (LCST) of 32 °C dispersed on a matrix of N-isopropylacrylamide-co-dimethylacrylamide with an LCST at 40 °C. Incubation of the hydrogel at 33 °C in a solution of fluorescein-albumin induced loading of the protein. The protein was not loaded at a temperature below the LCST of the microgels (4 °C), suggesting that the shrinkage of the microgels followed by the formation of micropores within the hydrogel matrix is a prerequisite for protein loading. A sustained and complete release of the loaded protein was obtained at 37 °C.

Because of its unique mechanical, chemical, and biological properties, 3D-printed polyether ether ketone (PEEK) has great potential as customized bone replacement and other metal alloy implant replacement. PEEK samples were printed using fused deposition modeling (FDM) and evaluated in terms of their dimensional accuracy, crystallinity, and mechanical properties. Crystallinity and mechanical properties increased with elevated chamber temperature and post-printing annealing. Variations of material properties from three printers are evident. Many factors affect the quality of 3D-printed PEEK. Future FDA regulations for 3D-printed products are needed for this highly customizable manufacturing process to ensure safety and effectiveness for biomedical applications.

Nanoparticle-mediated drug delivery has the potential to overcome several limitations of cancer chemotherapy. Lipid polymer hybrid nanoparticles (LPHNPs) have been demonstrated to exhibit superior cellular delivery efficacy. Hence, doxorubicin (a chemotherapeutic drug)-loaded LPHNPs have been synthesized by three-dimensional (3D)-printed herringbone-patterned multi-inlet vortex mixer. This method offers rapid and efficient mixing of reactants yielding controllable and reproducible synthesis of LPHNPs. The cytotoxicity of LPHNPs is tested using two-dimensional (2D) and 3D microenvironments. Results obtained from 3D cell cultures showed major differences in cytotoxicity in comparison with 2D cultures. These results have broad implications in predicting in vitro LPHNP toxicology.

Pseudo-line tensions are used in a continuum approach to simulate contact angle hysteresis. A pair of pseudo-line tensions in the receding and advancing states, respectively, are utilized to represent contact line interactions with a substrate because of the nanoscale topological and/or chemical heterogeneity on the substrate. A water droplet sitting on a horizontal or inclined substrate, whose volume is 4–30 µL, has been studied experimentally and numerically. Our simulation model predicts consistent hysteresis at four different droplet sizes compared with experiments. Meanwhile, the critical roll-off angles captured in simulations match well with experiments.

The authors carried out matched experiments and molecular dynamics simulations of the compression of nanopillars prepared from Cu|Au nanolaminates with up to 25 nm layer thickness. The stress–strain behaviors obtained from both techniques are in excellent agreement. Variation in the layer thickness reveals an increase in the strength with a decreasing layer thickness. Pillars fail through the formation of shear bands whose nucleation they trace back to the existence of surface flaws. This combined approach demonstrates the crucial role of contact geometry in controlling the deformation mode and suggests that modulus-matched nanolaminates should be able to suppress strain localization while maintaining controllable strength.

Excitation of surface waves on conducting materials provides a near resistance-free interface capable of a material glissade either by plasmon forces or by optical beam tractors. Analogous to an ice hockey rink, as proof-of-principle plasmon-assisted optical traction, or hoovering, of water drops on a gold surface is demonstrated. Changes in the contact angle provide a novel, low-cost nanoscale method of quantifying observable and potentially tunable changes. Variability in thresholds and movement, including jumps, is observed and can be explained by the presence of significant roughness, measured by scanning electron microscopy, with water tension. The demonstration opens a path to directly integrate various optical and plasmonic traction technologies. Implications of the phenomena and ways of improving transport and potential applications spanning configurable microfluidics, antennas, tunable lenses, diagnostics, sensing, and active Kerr and other devices are discussed.

A process for bioconjugation of an IgG antibody and silicon quantum dots (Si-QDs) having the luminescence in the near-infrared (NIR) range was developed. For the bioconjugation, the surface of water-soluble all-inorganic Si-QDs was functionalized by using silane-coupling agents. In amino-functionalized Si-QDs, successful conjugation was achieved without strongly affecting the luminescence property. Detailed analyses revealed that Si-QDs are bound covalently to both the light and heavy chains of an IgG antibody. It was also confirmed that the binding property of an IgG antibody with antigen nucleoprotein was not ruined by the process. The successful conjugation of an IgG antibody and NIR luminescent Si-QDs paves the way for designing environmentally friendly bio-sensing and -imaging processes.

The third-order nonlinear optical (NLO) susceptibility for morphologically controlled polydiacetylene (PDA) nanocrystals (NCs) and PDA nanofibers (NFs) have been determined for the first time by the experimental combination of transient pump-probe spectroscopy and spectroscopic ellipsometry. The figure of the merit of PDA NFs was much superior to PDA NCs and/or PDA bulk crystals, and the excitonic relaxation time was of order of sub-pico second. Namely, this is the first case to reveal the morphological effect on NLO response. PDA NFs having the long effective π-conjugation length are one of the most promising organic third-order NLO nanomaterials toward the photonic device application.

In this work, the effect of temperature, in the range of 25 to 250 °C, on deformation twinning in textured polycrystalline pure magnesium (Mg) was investigated. Compression loading was applied perpendicular to the c-axis texture direction. The yield strength and strain hardening rate are shown to drastically decrease with increasing temperature with total suppression of twinning at 200 °C. This behavior is attributed to the decrease in the critical resolved shear stress for prismatic slip and temperature insensitivity of tensile twinning. These results provide a first step in fundamentally understanding the deformation of Mg at elevated temperatures and quantify the mechanisms that lead to their improved formability at elevated temperatures.