The microcrystalline fibers of N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide 1 provided a useful model system for studying the complex relationship between morphology, experimental parameters, solvent, and the phenomenon of organogelation. The presence of solvents in the solid forms of 1 along with crystallization behavior suggested solvate formation and polymorphic behavior.Forty solid state- and xerogel samples of 1 formed in organic solvents and in three categories of experimental conditions were analyzed with single crystal X-ray diffraction (XRD), powder X-ray diffraction (PXRD), Raman microscopy, and attenuated total reflection Fourier-transform infrared spectroscopy (ATR FTIR).Two polymorphs and four isostructural aromatic solvates of 1 were found among some unknown forms in the samples. Single crystal X-ray structures of one polymorph and bromobenzene solvate were obtained, the latter from a xerogel. Multiple crystal forms could be present in a sample, and their contributions to gelation were estimated taking the experimental conditions into account. Gelator 1 could act as a variable component gelator, either alone or in combination with an aromatic solvent. The research brings new insight into the structures of microcrystalline organogel fibers, linking solvate/inclusion crystal formation with microcrystalline fibers of an organogelator for the first time.

We investigate the axisymmetric homogeneous growth of 10–100nm water nanodroplets on a substrate surface. The main mechanism of droplet growth is attributed to the accumulation of laterally diffusing water monomers, formed by the absorption of water vapour in the environment onto the substrate. Under assumptions of quasi-steady thermodynamic equilibrium, the nanodroplet evolves according to the augmented Young–Laplace equation. Using continuum theory, we model the dynamics of nanodroplet growth including the coupled effects of disjoining pressure, contact angle and monomer diffusion. Our numerical results show that the initial droplet growth is dominated by monomer diffusion, and the steady late growth rate of droplet radius follows a power law of 1/3, which is unaffected by the substrate disjoining pressure. Instead, the disjoining pressure modifies the growth rate of the droplet height, which then follows a power law of 1/4. We demonstrate how spatial depletion of monomers could lead to a growth arrest of the nanodroplet, as observed experimentally. This work has further implications on the growth kinetics, transport and phase transition of liquids at the nanoscale.

In this paper, we report different coordinations of citrates on gold (AuNP) and silver (AgNP) nanoparticles, as determined using Fourier transform infrared spectroscopy (FTIR) and molecular orbital (MO) calculations. AuNPs and AgNPs are found to have completely different interactions with the carboxylate anchoring groups, as indicated by their unique asymmetric stretching vibrations in the FTIR spectra. The νas (COO⁻) of citrate exhibits a high-frequency shift resulting from the formation of a unidentate coordination on AuNPs, whereas this vibration exhibits a low-frequency shift as a result of ionic bond formation on AgNPs, as predicted from the MO calculations of the corresponding metal complex salts. The enhancement in the IR signals when their vibration direction was perpendicular to the nanoparticle surface revealed the influence of localized surface plasmons excited on the metal nanoparticles.

In this paper, we chose rice husk as raw material and synthesized successfully porous carbon loaded with silver nanoparticles (RH-Ag) composites by simple and cost-effective method. The as-prepared RH-Ag composites have a BET-specific surface area of 1996m²g⁻¹ and result in strong capacity of bacteria adsorption. The result of antibacterial study indicated that the RH-Ag system displayed antibacterial activity that was two times better than pure Ag NPs. Our study demonstrates that the antibacterial activity of RH-Ag composites may be attributed to their strong adsorption ability with bacteria and result in the disorganization of the bacterial membrane ultrastructure. In addition, RH-Ag system was found to be durative slow-releasing of silver ions and biocompatible for human skin keratinocytes cells. In terms of these advantages, the RH-Ag composites have potential application in antibacterial infections and therapy.

The Fe²⁺ doped ZnSe nanorods are synthesized using simple potentiostatic mode of electrodeposition on the ITO substrate. In order to study the doping effect of Fe²⁺ in ZnSe, varied the doing percent such as 0.5%, 1%, 1.5%. These films are characterized for structural, compositional, morphological, optical and electrochemical properties using the X-ray diffraction study (XRD), X-ray photoelectron spectroscopy, field emission scanning electron microscopy, UV–vis spectroscopy and electrochemical spectroscopy. Along with these Raman spectroscopy and photoluminescence spectroscopy have been studied for understanding the characteristics vibrations of ZnSe and luminescence of ZnSe nanorods. FE-SEM shows the nanorods like morphology. Photoelectrochemical cell performance studied using the J–V measurement and it shows the maximum efficiency at 1% Fe²⁺ doped ZnSe nanorods. The observed maximum efficiency of Fe²⁺ doped ZnSe nanorods is 0.32%.

Metal nanocrystal/metal–organic framework core/shell nanostructures have been constructed using metal ion-trapped nanocrystals as scaffolds through a selective self-assembly of framework components on the nanocrystal surfaces. The resulting nanostructures exhibit unique catalytic activity toward nitrophenol analogs.

Significant increase of the adsorption ability of the eggshell biomaterial toward cadmium was observed upon milling, as is evidenced by the value of maximum monolayer adsorption capacity of 329mgg⁻¹, which is markedly higher than in the case of most “green” sorbents. The main driving force of the adsorption was proven to be the presence of aragonite phase as a consequence of phase transformation from calcite occurring during milling. Cadmium is adsorbed in a non-reversible way, as documented by different techniques (desorption tests, XRD and EDX measurements). The optimum pH for cadmium adsorption was 7. The adsorption process was accompanied by the increase of the value of specific surface area. The course of adsorption has been described by Langmuir, Freundlich and Dubinin–Radushkevich isotherms. The adsorption kinetics was evaluated using three models, among which the best correlation coefficients and the best normalized standard deviation values were achieved for the pseudo-second order model and the intraparticle diffusion model, respectively.

We report a comprehensive study of laser-initiated, liquid-assisted colloidal (LILAC) lithography, and illustrate its utility in patterning silicon substrates. The method combines single shot laser irradiation (frequency doubled Ti–sapphire laser, 50fs pulse duration, 400nm wavelength) and medium-tuned optical near-field effects around arrays of silica colloidal particles to achieve 3-D surface patterning of silicon. A monolayer (or multilayers) of hexagonal close packed silica colloidal particles act as a mask and offer a route to liquid-tuned optical near field enhancement effects. The resulting patterns are shown to depend on the difference in refractive index of the colloidal particles (ncolloid) and the liquid (nliquid) in which they are immersed. Two different topographies are demonstrated experimentally: (a) arrays of bumps, centred beneath the original colloidal particles, when using liquids with nliquid<ncolloid, and (b) a combination of holes, created in the interstices between the colloidal particles, and bumps when using liquids with nliquid>ncolloid – and explained with the aid of complementary Mie scattering simulations. The LILAC lithography technique has potential for rapid, large area, organized 3-D patterning of silicon (and related) substrates.

The design of nanostructured drug delivery systems (DDS) that improve the efficacy of therapeutic principles by enhancing their biocompatibility, bioavailability and targeting, has been the focus of extensive research over the past years. Of particular relevance in this field is the development of multifunctional architectures that can deliver different therapeutics or diagnostic agents and release them in a controlled way. In this study we report on the design, preparation and characterization of a DDS where hydrophobic Fe3O4 magnetic nanoparticles (NPs) are included in the bilayer of bicontinuous cubic lipid nanoparticles of Glyceryl Monooleate (GMO). The “magnetocubosomes” are characterized and investigated in terms of their ability to encapsulate and release both hydrophilic and hydrophobic model drugs. For the first time Fluorescence Correlation Spectroscopy (FCS) is used to study the diffusion of encapsulated molecules inside the bicontinuous cubic phase and to monitor their release from the matrix towards the aqueous phase. In addition, we show with the same technique that magnetocubosomes are responsive to a low frequency alternating magnetic field (LF-AMF), which acts as an external trigger to boost the release of model drugs confined in the cubic phase. Magnetocubosomes, reported for the first time in this paper, represent a novel biocompatible, multifunctional and responsive DDS.

Highly crystalline flake-like CuCeO2−δ composites (strCCx) with large specific surface area and developed mesoporosity were prepared using an economic and effective bio-template route. Modified starch with abundant surface carboxyl groups was adopted as the chelating agent and template for metal cations immobilization via electrostatic attraction predominately based on the process of –COO⁻⋯Cu²⁺ and –COO⁻⋯Ce³⁺. Physicochemical properties of prepared materials were systematically explored by FT-IR, XRD, TG, N2 adsorption/desorption, FE-SEM, TEM, H2-TPR, O2-TPD, XPS, DRUV–Vis, and XAFS techniques. Propanal as a typical oxygen-contained VOC was adopted as the probe pollutant to evaluate the catalytic performance of synthesized materials. Characterization results reveal that plenty of copper ions in composite oxides are incorporated into CeO2 lattice, which produces oxygen vacancies and enhances metal reducibility. Both specific surface area and pore volume of strCCx samples decreased with the increasing of Cu loading. The flake-like CuCeO2−δ sample (Cu/(Cu+Ce)=0.15) with highest specific surface area (108.2m²/g) and surface oxygen concentration is indentified as the most active catalyst with propanal totally destructed at 230°C. The introduction of H2O has a negative effect on propanal removal, and the synthesized catalyst has high tolerance to moisture. In conclusion, the specific surface area and surface oxygen density are two vital factors governing the catalytic activity of composite catalysts.