Drying of Hierarchically Organized Porous Silica Monoliths-Comparison of Evaporative and Supercritical Drying.

In this study, we present a detailed comparison between a conventional supercritical drying process and an evaporative drying technique for hierarchically organized porous silica gel monoliths. These gels are based on a model system synthesized by the aqueous sol-gel processing of an ethylene-glycol-modified silane, resulting in a cellular, macroporous, strut-based network comprising anisotropic, periodically arranged mesopores formed by microporous amorphous silica. The effect of the two drying procedures on the pore properties (specific surface area, pore volume, and pore widths) and on the shrinkage of the monolith is evaluated through a comprehensive characterization by using nitrogen physisorption, electron microscopy, and small-angle X-ray scattering.

Polyvinylidene Fluoride Aerogels with Tailorable Crystalline Phase Composition.

In this work, polyvinylidene fluoride (PVDF) aerogels with a tailorable phase composition were prepared by following the crystallization-induced gelation principle. A series of PVDF wet gels (5 to 12 wt.%) were prepared from either PVDF−DMF solutions or a mixture of DMF and ethanol as non-solvent.

Tannin-Based Nanoscale Carbon Spherogels as Electrodes for Electrochemical Applications.

A promising route to monolithic, hollow sphere carbon assemblies based on sustainable precursors with a tailored nanostructure is presented. These carbon assemblies, recently termed carbon spherogels, are generated via a polystyrene sphere template-based sol-gel process of mimosa tannin and biomass-derived 5-(hydroxymethyl)furfural. By completely replacing petroleum-based precursors (especially toxic formaldehyde) highly porous, nanoscale carbon monoliths are obtained, which are investigated as state-of-the-art, sustainable electrode materials for energy storage.

Gene regulatory effects of a large chromosomal inversion in highland maize.

Chromosomal inversions play an important role in local adaptation. Inversions can capture multiple locally adaptive functional variants in a linked block by repressing recombination. However, this recombination suppression makes it difficult to identify the genetic mechanisms underlying an inversion's role in adaptation.

Tannin-Based Hybrid Materials and Their Applications: A Review.

Tannins are eco-friendly, bio-sourced, natural, and highly reactive polyphenols. In the past decades, the understanding of their versatile properties has grown substantially alongside a continuously broadening of the tannins' application scope. In particular, recently, tannins have been increasingly investigated for their interaction with other species in order to obtain tannin-based hybrid systems that feature advanced and/or novel properties.

Rare-Earth Zirconate LnZrO (Ln: La, Nd, Gd, and Dy) Powders, Xerogels, and Aerogels: Preparation, Structure, and Properties.

The physicochemical properties of rare-earth zirconates can be tuned by the rational modification of their structures and phase compositions. In the present work, La-, Nd-, Gd-, and Dy-zirconate nanostructured materials were prepared by different synthetic protocols, leading to powders, xerogels, and, for the first time, monolithic aerogels. Powders were synthesized by the co-precipitation method, while xerogels and aerogels were synthesized by the sol-gel technique, followed by ambient and supercritical drying, respectively.