Continuous Mesoporous Pd Films by Electrochemical Deposition in Nonionic Micellar Solution

Mesoporous metals that combine catalytic activity and high surface area can provide more opportunities for electrochemical applications. Various synthetic methods, including hard and soft templating, have been developed to prepare mesoporous/nanoporous metals. Micelle assembly, typically involved in soft-templates, is flexible and convenient for such purposes. It is, however, difficult to control, and the ordering is significantly destroyed during the metal deposition process, which is detrimental when it comes to designing precisely mesostructured materials. In the present work, mesoporous Pd films were uniformly electrodeposited using a nonionic surfactant, triblock copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), as a pore-directing agent. The interaction between micelles and metal precursors greatly influences the metal growth and determines the final structure. The water-coordinated species interact with the ethylene oxide moiety of the micelles to effectively drive the Pd(II) species toward the working electrode surface. From small-angle neutron scattering data, it is found that spherical P123 micelles, with an average diameter of ∼14 nm, are formed in the electrolyte, and the addition of Pd ions does not significantly modify their structure, which is the essence of the micelle assembly approach. The uniformly sized mesopores are formed over the entire mesoporous Pd film and have an average pore diameter of 10.9 nm. Cross-sectional observation of the film also shows mesopores spanning continuously from the bottom to the top of the film. The crystallinity, crystal phase, and electronic coordination state of the Pd film are also confirmed. Through this study, it is found that the optimized surfactant concentration and applied deposition potential are the key factors to govern the formation of homogeneous and well-distributed pores over the entire film. Interestingly, the as-prepared mesoporous Pd films exhibit superior electrocatalytic activity toward the ethanol oxidation reaction by fully utilizing the accessible active surface area. Our approach combines electrochemistry with colloidal and coordination chemistry and is widely applicable to other promising metals and alloy electrocatalysts. © 2017 American Chemical Society

Le transport de boutures de café et le repiquage avec traitement sucre (saccharose) et sans sucre, longueur des racines, durée et type d'emballage (carton et boîte isotherme)

Durant ce travail réalisé à la station IRCC de Divo (Côte d'Ivoire), diverses modalités de préparation et de transport de boutures de caféier Robusta ont été testées : traitement par pulvérisation d'une solution de saccharose (300 g/3 l d'eau); emballage dans des cartons ou des boîtes isothermes; raccourcissement des racines à 5, 8 ou 10 cm; durées de transport (maintien dans l'emballage) de 4 à 12 jours. Les critères étudiés le jour du repiquage (présence de feuilles et couleur des feuilles et des racines) et 75 jours après (taux de mortalité) ne montrent aucune différence significative entre les diverses modalités testées. Seule la durée d'emballage a un net effet négatif sur le taux de survie qui, d'environ 50 % après 6 jours de transport, diminue rapidement au del

NUTRIENT DIGESTIBILITY OF THE WASTE OF SACCHARIFICATION PROCESS FROM CASSAVA BAGASSE ON THE LAYING HENS

The objective of this research was to study the nutrient digestibility and the metabolizable energyvalue of the waste of saccharification process from cassava bagasse (WSPCB) on the laying hens.Twenty ISA-Brown laying hens at the age of 72 weeks were randomly distributed into three feedingtreatments which consisted of cassava bagase (CB), WSPCB of solid state fermentation method(WSPCB-SSF), and WSPCB of sub merged fermentation method (WSPCB-SmF). All of the hens werefasted for 24 hours and 15 of them were fed with CB, WSPCB-SSF and WSPCB-SmF (five hens foreach test-diet). The other five hens were still fasted. Then, all of the hens were fasted again and theirexcreta were collected during 48 hours. The nutrient digestibilities which were measured consisted ofthe Apparent and True Digestibility of Dry matter (ADDM and TDDM), Crude Fiber (ADCF andTDCF), Starch (ADS and TDS), and the Apparent and True Metabolizable Energy (AME and TME).The result of this research showed that the saccharification process generated the solid waste with thenutrient digestibility value (ADDM, TDDM, ADS, TDS, AME, and TME) which were significantlylower (P<0.05) than those of CB. The crude fiber digestibility value of the WSPCB has an opositephenomenon in which the ADCF and TDCF of WSPCB-SmF were greater than CB. In conclusion, thenutrient digestibility value, except for ADCF and TDCF, of the WSPCB on the laying hens were lowerin value than those CB

Performance of metal-organic frameworks in the electrochemical sensing of environmental pollutants

Environmental pollution has been a known threat to our world due to the rapid urbanization, changing lifestyle of people, and modern industrialization. Therefore, there is an urgent need to develop novel sensing approaches having promising performance with high reliability and sensitivity for the precise monitoring of various pollutants. Metal-organic frameworks (MOFs) have been intensively investigated by many researchers as electrode modifiers for electrochemical sensing due to their excellent properties and efficiency. Diverse MOF-based electrochemical sensing systems are applied for environmental analysis for the sensitive, rapid and cost-effective determination of various analytes because of their unique structures, and properties, including the tunable pore size, high surface area, high catalytic activity, and high density of active sites. The aim of this review article is to evaluate the application of MOFs in the electrochemical sensing of environmental pollutants including heavy metal ions, pesticides, phenolic compounds, nitroaromatic compounds, antibiotics, nitrite, and hydrazine. Current limitations and future directions for the application of MOF-based electrochemical sensors for the detection of environmental pollutants are discussed. © The Royal Society of Chemistry 2021

Imaging SPR combined with stereoscopic 3D tracking to study barnacle cyprid-surface interactions

Barnacle larvae (cyprids) explore surfaces to identify suitable settlement sites. This process is selective, and cyprids respond to numerous surface cues. To better understand the settlement process, it is desirable to simultaneously monitor both the surface exploration behavior and any close interactions with the surface. Stereoscopic 3D tracking of the cyprids provides quantitative access to surface exploration and pre-settlement rituals. Imaging surface plasmon resonance (SPR) reveals any interactions with the surfaces, such as surface inspection during bipedal walking and deposition of temporary adhesives. We report on a combination of both techniques to bring together information on swimming behavior in the vicinity of the interface and physical interactions of the cyprid with the surface. The technical requirements are described, and we applied the setup to cyprids of Balanus amphitrite. Initial data shows the applicability of the combined instrument to correlate exploration and touchdown events on surfaces with different chemical termination. (C) 2015 Published by Elsevier B.V.Funding Agencies|European Communitys Seventh Framework Programme FP7 [23797]; Office of Naval Research [N000141210498, N000141512324, N00014-13-1-0634, N00014-13-1-0633]</p