Preparation of iridium nano-and submicroparticles on solid substrates by direct surface growth and drop-drying assembly

Iridium nanoparticles (IrNPs) and submicroparticles (IrSMPs) with different shapes were synthesized and assembled on indium thin oxide (ITO) and Si substrates using two different methods: direct surface growth and drop-drying assembly. The obtained IrNPs and IrSMPs were characterized using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The IrSMPs (or IrNPs) with disc-like shape and irregular shapes were obtained on ITO substrate by direct surface growth method using polyvinylpyrrolidone (PVP) and sodium citrate as different stabilizers, respectively. The reaction time and the injection temperature of reducing agent are found to have great effect on the size and morphology of the surface-grown Ir particles. The disc-like, ellipsoidal, and spherical IrSMPs (or IrNPs) were also synthesized in homogeneous solution in the presence of H3BO3 and Na2B4O7 as assistant-stabilizer. These IrNPs and IrSMPs were used as building blocks to construct nanoparticle assemblies by using a simple drop-drying method. Uniform IrNP and IrSMP assemblies were successfully prepared on Si and ITO substrates, indicating that the drop-drying method is efficient for the preparation of not only nanoparticle assemblies but also submicroparticle assemblies.

New Properties of HM16 Ether, with Submicroparticles as Self-Functional Cells Interacting through Percussion Forces, Establishing Nature of Electrical Charges, including Gravitation

Article continues and complements our previous articles on the HM16 ether (ETH) model. Here, we describe the mechanism of occurrence of the submicroparticle (SMP). A general hypothesis, HFVI, is introduced for the modalities of interaction between two SMPs, based on periodic mechanical percussion forces, produced by fundamental vibrations FVs. A mechanism for describing the interaction between a SMPs and the ETH is presented. Positive and negative particles are defined by their membrane types of movement, such as +, −u/+, −v vibrations, and rotations at speeds +Ω/−Ω. The process of creating a pair of SMPs is discussed. Applying HFVI to the interaction between pairs of SMPs immobile in ETH, and considering longitudinal FVL, was obtained the forces of attraction/repulsion +FL21/–FL21, which correspond to the completed Coulomb force FCC including gravitation. The resultant FRL21 will form an oriented field of forces, which is a quasielectric field QE, equivalent to actual E electric field. Considering transversal FVT, was obtained the vibratory forces +, −FT21, whose resultant forms an vibrating field of forces, QHs, a quasimagnetic special field, which may explain some of the quantum properties of SMPs. Considering a mobile SMP, two new γ strains in ETH appear. Strains γL are created by the displacement of SMP with velocity V, whose force +, −FT12 is the support of a component of the magnetic field H (quasimagnetic field QH), giving the QHL component. Strains γR are created by the rotation of SMP with speed Ω, whose force +, −FR12 constitutes physical support of the component QHR of magnetic field H (i.e. QH). The creation of a photon PH is modelled as a special ESMP containing two zones of opposed rotations, and a mechanism is presented for its movement in the ETH with speed c based on the HS hypothesis of screwing in ETH, with frequency ν.

Low temperature solid-state synthesis and characterization of uniform YF_3 submicroparticles

In this paper, submicro-scaled YF3 particles with uniform rice-like morphologies were facilely synthesized by reacting yttrium nitrate with tetrabutylammonium fluoride via a solid-state reaction process at 50 °C for 12 h.The phase confirmation and morphology of the as-prepared YF3 particles were investigated by X-ray powder diffraction（XRD） and scanning electron microscopy（SEM）.SEM results reveal that the YF3 submicroparticles are about 700 nm in length and 260 nm in width. Eu^3＋ and Tb^3＋ doped YF3 submicroparticles were also prepared with similar process and their photoluminescence properties were studied. Results demonstrate that the doping of Eu^3＋ and Tb^3＋ has slight effect on the morphologies of the product. Owing to the small average crystallite size or the low crystallinity of the product, the photoluminescence intensity of the Eu^3＋ and Tb^3＋ doped YF3 submicroparticles is very weak. Some characteristic peaks even cannot be observed in the emission spectrum.

Discovery,characterization and stability evaluation of self-assembled submicroparticles in chrysanthemum tea infusions

Chrysanthemum tea infusions are famous and nutritious beverages worldwide.The results showed that numerous negatively charged spherical particles of 60–1000 nm in diameter generally existed in all chrysanthemum tea infusions prepared from 9 kinds of chrysanthemums for tea use.Taking Chrysanthemum morifolium ‘Hangbaiju ’ tea infusion as an example,crushing,heating and increasing flower-to-water ratio were three strategies to prepare optimal submicroparticles with the smallest mean hydrodynamic diameter as 288.40 nm and polydispersity index as 0.25.The submicroparticles were stable when temperature change,dialysis,centrifugation,storage,pH change (2–9) and ionic strength change were applied but unstable when freeze-thaw,lyophilization,ultrafiltration,concentration and pH change (10) were applied.Polysaccharides and phenolics were dominant components of submicroparticles which were maintained by hydrogen bonds and hydrophobic interactions among polysaccharides and phenolics.This study provided a novel perspective to decipher and control supramolecular aggregation in chrysanthemum tea infusions for rational manufacturing.