Cartermohamed6950

A microkinetics model is proposed toward conductivities, triple-conducting pathways, reactant dependency, surface exchange and bulk diffusion capabilities, and other relevant properties. Finally, the rate-limiting steps and suggestions for further improvement of electrode performance are presented.Understanding colloid transport in subsurface environments is challenging because of complex interactions among colloids, groundwater, and porous media over several length scales. Here, we report a versatile method to assemble bead-based microfluidic porous media analogues with chemical heterogeneities of different configurations. We further study the transport of colloidal particles through a family of porous media analogues that are randomly packed with oppositely charged beads with different mixing ratios. We recorded the dynamics of colloidal particle deposition at the level of single grains. From these, the maximum surface coverage (θmax = 0.051) was measured directly. The surface-blocking function and the deposition coefficient (kpore = 3.56 s-1) were obtained. Using these pore-scale parameters, the transport of colloidal particles was modeled using a one-dimensional advection-dispersion-deposition equation under the assumption of irreversible adsorption between oppositely charged beads and colloids, showing very good agreement with experimental breakthrough curves and retention profiles at the scale of the entire porous medium analogue. This work presents a new approach to fabricate chemically heterogeneous porous media in a microfluidic device that enables the direct measurement of pore-scale colloidal deposition. Compared with the conventional curve-fitting method for deposition constant, our approach allows quantitative prediction of colloidal breakthrough and retention via coupling of direct pore-scale measurements and an advection-dispersion-deposition model.Nanofluidic devices have become a powerful tool for extremely precise analyses at a single-molecule/nanoparticle level. However, a simple and sensitive molecular detection method is essential for nanofluidic devices because of ultrasmall volume (fL-aL). One such technology is photothermal spectroscopy (PTS), which utilizes light absorption and thermal relaxation by target molecules. Recently, we developed a photothermal optical diffraction (POD) detection method as PTS for nanofluidic devices. However, the detectable concentration range was in the order of μM (102 to 104 molecules), and further improvement in detection performance is strongly required. Here, we demonstrate solvent-enhanced POD with optimized experimental conditions and show its capability of concentration determination of nonfluorescent molecules in nanochannels at a countable molecular level. A relationship between the POD signal and thermal/optical properties of solvents is elucidated. We estimate the diffraction factor and photothermal factor of the solvent enhancement effect by thermal simulations and theoretical calculations. check details Experimental results show good agreement with the prediction, and the detection performance of the POD is successfully improved. At the optimized condition, we demonstrate the concentration determination with the limit of detection of 75 nM, which corresponds to an average of 10 molecules in a detection volume of 0.23 fL. Our sensitive nonfluorescent molecule detection method will be applied to a wide range of chemical/biological analyses utilizing nanofluidics.Versatile host materials with good chemical stability and carrier-transporting ability are quite responsible for achieving stable solution-processed thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, we reported three bipolar dendritic hosts with or without the electron-withdrawing pyridine moiety via 6-site-linkages, namely, 3,3'-bis(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3'6',9″-tercarbazol]-9'-yl)-1,1'-biphenyl (mCDtCBP), 3,3″,6,6″-tetra-tert-butyl-9'-(6-(3-(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3'6',9″-tercarbazol]-9'-yl)phenyl)pyridine-2-yl)-9'H-9,3'6',9″-tercarbazole (mCDtCBPy), and 6,6'-bis(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3'6',9″-tercarbazol]-9'-yl)-2,2'-bipyridine (mCDtCBDPy), exhibiting outstanding solubility, thermal stability as well as electrochemical stability. According to the calculation of bond dissociation energy (BDE), photodegradation results, and carrier dynamics evaluation, a significant relationship between device stability and the pyridine-based dendritic hosts was uncovered. Using mCDtCDPy with the highest electron mobility as the host, the solution-processed bluish-green TADF-OLED showed the shortest operational lifetime due to the unbalanced charge fluxes despite its highest anionic BDE for good chemical stability. However, the device based on mCDtCBPy exhibited twice longer lifetime than that based on mCDtCBP in spite of their similar balanced charge transportation, highlighting the importance of higher anionic BDE of the C-N bond in the device degradation process. Our findings unveiled a potential approach to achieve a subtle regulation of chemical stability and carrier transportation for realizing stable solution-processed TADF-OLEDs.Diphylleia grayi-inspired hydrochromic nano/microstructured films have received much attention for its promising smart hydrochromic applications owing to their simple and low-cost but energy-effective strategy. A new type of water-switchable glazing film patterned with various nano/micro air-hole inverse opal arrays is introduced by selectively removing nano/microsphere polystyrene arrays embedded in the surface of polydimethylsiloxane (PDMS) films. Using the significant contrast ratio of the bleaching and the scattering states, we have optimized the switching properties of Mie scattered patterns. As a result, we obtained a single inverse opal layer-embedded PDMS adhesive film with hexagonally close-packed 1 μm air-hole arrays as an optimum scattered film. The differences of diffusive transmittance and optical haze values between the dry and the wet states of the best scattered film reached 44.93% (ΔTD.T = 59.11-14.18%) and 54.88% (ΔH = 69.42-14.54%), respectively. In addition, using the best-optimized inverse opal layer-embedded PDMS film, we fabricated a perfectly imitated Diphylleia grayi structure for camouflage application and an intelligent hydrochromic window device.