The formation of crystalline calcium phosphate (CaP) has recently gained ample attention as it does not follow the classic nucleation-and-growth mechanism of solid formation. Instead, the precipitation mechanisms can involve numerous intermediates, including soluble prenucleation species. However, structural features, stability, and transformation of such solution-state precursors remain largely undisclosed.
View Article and Find Full Text PDFUnderstanding how water interacts with nanopores of carbonaceous electrodes is crucial for energy storage and conversion applications. A high surface area of carbonaceous materials does not necessarily need to translate to a high electrolyte-solid interface area. Herein, we study the interaction of water with nanoporous CN materials to explain their very low specific capacitance in aqueous electrolytes despite their high surface area.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
October 2023
Nuclear magnetic resonance (NMR) spectroscopy is a key method for the determination of molecular structures. Due to its intrinsically high (, atomistic) resolution and versatility, it has found numerous applications for investigating gases, liquids, and solids. However, liquid-state NMR has found little application for suspensions of solid particles as the resonances of such systems are excessively broadened, typically beyond the detection threshold.
View Article and Find Full Text PDFHydrothermal carbonization (HTC) is an efficient thermochemical method for the conversion of organic feedstock to carbonaceous solids. HTC of different saccharides is known to produce microspheres (MS) with mostly Gaussian size distribution, which are utilized as functional materials in various applications, both as pristine MS and as a precursor for hard carbon MS. Although the average size of the MS can be influenced by adjusting the process parameters, there is no reliable mechanism to affect their size distribution.
View Article and Find Full Text PDFCarbon suboxide (C O ) is a unique molecule able to polymerize spontaneously into highly conjugated light-absorbing structures at temperatures as low as 0 °C. Despite obvious advantages, little is known about the nature and the functional properties of this carbonaceous material. In this work, the aim is to bring "red carbon," a forgotten polymeric semiconductor, back to the community's attention.
View Article and Find Full Text PDFTreatment of Na-based hectorite LAPONITE® (LAP) and of Na-montmorillonite (MMT) with a homologous series of γ-aminopropyl(methyl)(ethoxy)silanes ( + = 3, > 0) in toluene was studied by means of thermogravimetric analysis coupled with mass spectrometry, infrared spectroscopy, Si and Na solid-state nuclear magnetic resonance spectroscopy and powder X-ray diffraction. The triethoxy silane (APTS) exclusively grafts on the clays' edges as branched oligomers whereas both the monoethoxy silane (APMS) and the diethoxy silane (APDS) are also intercalated, the latter as linear oligomers. Intercalation of APMS varies for MMT and LAP: MMT hosts the smallest amounts of the silanes with marginal increase of the basal distance and no stabilization of water.
View Article and Find Full Text PDFThermally stabilized and subsequently carbonized nanofibers are a promising material for many technical applications in fields such as tissue engineering or energy storage. They can be obtained from a variety of different polymer precursors via electrospinning. While some methods have been tested for post-carbonization doping of nanofibers with the desired ingredients, very little is known about carbonization of blend nanofibers from two or more polymeric precursors.
View Article and Find Full Text PDFThe combined benefits of moisture-stable phosphonic acids and mesoporous silica materials (SBA-15 and MCM-41) as large-surface-area solid supports offer new opportunities for several applications, such as catalysis or drug delivery. We present a comprehensive study of a straightforward synthesis method via direct immobilization of several phosphonic acids and phosphoric acid esters on various mesoporous silicas in a Dean⁻Stark apparatus with toluene as the solvent. Due to the utilization of azeotropic distillation, there was no need to dry phosphonic acids, phosphoric acid esters, solvents, or silicas prior to synthesis.
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