Abstract:Graphical abstractHighlights► The size of amorphous SiO2
nanoparticles coincides for different test methods. ► Different
measurement methods deliver different values for crystalline
ZrO2 nanoparticles. ► The use of complementary
methods is favourable.
“…They may be polycrystalline or clusters of many smaller nanocrystallites. [16] They may also be hollow crystals, or crystals containing many defects or have incorporated organic matrix. [17,18] All types of crystal imperfections would lead to extra XRD peak broadening due to microstrain, resulting in a smaller value of crystal size.…”
Transmission electron microscopy is a powerful tool to directly image crystal structures. Not only that, it is often used to reveal crystal size and morphology, crystal orientation, crystal defects, surface structures, superstructures, etc. However, due to the 2D nature of TEM images, it is easy to make mistakes when we try to recover a 3D structure from them. Scanning electron microscopy is able to provide information on the parti-
“…They may be polycrystalline or clusters of many smaller nanocrystallites. [16] They may also be hollow crystals, or crystals containing many defects or have incorporated organic matrix. [17,18] All types of crystal imperfections would lead to extra XRD peak broadening due to microstrain, resulting in a smaller value of crystal size.…”
Transmission electron microscopy is a powerful tool to directly image crystal structures. Not only that, it is often used to reveal crystal size and morphology, crystal orientation, crystal defects, surface structures, superstructures, etc. However, due to the 2D nature of TEM images, it is easy to make mistakes when we try to recover a 3D structure from them. Scanning electron microscopy is able to provide information on the parti-
“…The SAXS patterns ( Figure 2a) were described by a model combining the unified scattering function of Beaucage [30] (resulting in a radius of gyration R g and a fractal dimension d f ) with a packing factor from a hard sphere model, [31,32] describing the agglomeration of units (distance R HS and hard sphere volume ratio η). The most striking differences are the larger size of Mg 0.…”
is the most ubiquitously used form of energy, including in electricity generation, power plants, or industry. [5] In this context, in 2011, the International Energy Agency estimated in a report entitled "Solutions for a low-carbon energy future" that global energy loss through waste heat accounts for two-third of the overall energy production. [6] Therefore, methods suitable for reduction of waste heat or reutilization thereof could contribute significantly to a sustainable energy management. [7][8][9] Among the different approaches to this challenge, thermochemical energy storage (TCES) is a highly appealing concept, since by means of a reversible chemical reaction, a suitable material energy is converted from thermal to chemical energy. The charged material may be stored for any period of time without further losses or additional infrastructure (such as insulation), until, by addition of the proper reactant, the discharging reaction, releasing the stored energy in form of heat, is initiated. [2,[10][11][12] The economic benefit of implementing TCES cycles in the energy management was demonstrated by several economic feasibility studies, illustrating that, e.g., with the waste heat from Lenzing AG, [13] Calcium doping of magnesium oxide results in significantly increased water dissociation rates, thus enhancing both hydration rate and reaction completeness of hydration compared to pure MgO. For a series of mixed magnesiumcalcium oxides (Mg x Ca 1−x O) with varying Ca contents between 0% and 40%, the material of a composition Mg 0.9 Ca 0.1 O shows the fastest rehydration, transforming completely within 80 min to the mixed hydroxide. In consecutive dehydration/rehydration cycles, reasonable cycle stability is found. A "regeneration" of the aged material (reactivity reduced by excessive cycling) in liquid water re-establishes the initial rehydration reactivity. Density functional theory calculations support the experimental findings, confirming that calcium doping can reduce the energy of the rate limiting water dissociation reaction, exploiting both electronic and steric (size) effects. Three major requirements for future sustainable energy management have been established including reduction of greenhouse gas emissions, promotion and increased use of renewable energy sources, and enhancing the efficiency of energy use. [1,2] Whereas the first two issues are widely discussed and the subject of international treaties such as the Kyoto protocol [3] and the Paris agreement, [4] awareness of the poor overall efficiency of today's energy economy is rather limited. Heat
“…This difference in the mean particle diameter from both methods is due to the difference in the measurement techniques; SAXS data results from the electron density contrast between the sample and solvent (Schnablegger and Singh 2013) whereas DLS data are derived from the hydrodynamic diameter of the particles, which depends on the surface morphology of the particles (Lim et al 2013) and any interactions between the particles and the medium (Kätzel 2007). Higher mean nanoparticle diameters from DLS measurements compared to SAXS analysis has previously been reported (Chen et al 2012; Pabisch et al 2012). However, DLS as a cheaper and quicker analysis technique is preferred over SAXS for the analysis of nanoparticles.…”
Section: Resultsmentioning
confidence: 60%
“…According to the TEM image, the mean particle size was 6.4 ± 0.4 nm, which was in accordance with the SAXS data. The higher diameter value obtained from the DLS data compared to SAXS and TEM analysis can be attributed to the effect of the hydrodynamic shell around the particles in solution (Pabisch et al 2012). Fig.…”
The synthesis of size-monodispersed indium nanoparticles via an innovative simultaneous phase transfer and ripening method is reported. The formation of nanoparticles occurs in a one-step process instead of well-known two-step phase transfer approaches. The synthesis involves the reduction of InCl3 with LiBH4 at ambient temperature and although the reduction occurs at room temperature, fine indium nanoparticles, with a mean diameter of 6.4 ± 0.4 nm, were obtained directly in non-polar n-dodecane. The direct synthesis of indium nanoparticles in n-dodecane facilitates their fast formation and enhances their size-monodispersity. In addition, the nanoparticles were highly stable for more than 2 months. The nanoparticles were characterised by dynamic light scattering (DLS), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy to determine their morphology, structure and phase purity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
