Melt Alloying of Two-Dimensional Hybrid Perovskites: Composition-Dependence of Thermal and Optical Properties.

Melt alloying, the process of melting a physical powder blend to create a homogeneous alloy, is widely used in materials processing. By carefully selecting the materials and their proportions, the physical properties of the resulting alloy can be precisely controlled. In this study, we investigate the possibility of utilizing melt alloying principles for meltable two-dimensional hybrid organic-inorganic perovskites (2D-HOIPs).

Long-lived enhanced magnetization-A practical metabolic MRI contrast material.

Noninvasive tracking of biochemical processes in the body is paramount in diagnostic medicine. Among the leading techniques is spectroscopic magnetic resonance imaging (MRI), which tracks metabolites with an amplified (hyperpolarized) magnetization signal injected into the subject just before scanning. Traditionally, the brief enhanced magnetization period of these agents limited clinical imaging.

How Does Local Strain Affect Stokes Shifts in Halide Double Perovskite Nanocrystals?

Lead-free perovskite nanocrystals are of interest due to their nontoxicity and potential application in the display industry. However, engineering their optical properties is nontrivial and demands an understanding of emission from both self-trapped and free excitons. Here, we focus on tuning silver-based double perovskite nanocrystals' optical properties via two iso-valent dopants, Bi and Sb.

High-Mg calcite nanoparticles within a low-Mg calcite matrix: A widespread phenomenon in biomineralization.

During the process of biomineralization, organisms utilize various biostrategies to enhance the mechanical durability of their skeletons. In this work, we establish that the presence of high-Mg nanoparticles embedded within lower-Mg calcite matrices is a widespread strategy utilized by various organisms from different kingdoms and phyla to improve the mechanical properties of their high-Mg calcite skeletons. We show that such phase separation and the formation of high-Mg nanoparticles are most probably achieved through spinodal decomposition of an amorphous Mg-calcite precursor.

Structural and chemical variations in Mg-calcite skeletal segments of coralline red algae lead to improved crack resistance.

The calcareous alga Jania sp. is an articulated coralline red seaweed that is abundant in the shallow waters of oceans worldwide. We have previously demonstrated that its structure is highly intricate and exhibits hierarchical organization across multiple length scales from the macro to the nano scale.

Acidic Monosaccharides become Incorporated into Calcite Single Crystals*.

Carbohydrates, along with proteins and peptides, are known to represent a major class of biomacromolecules involved in calcium carbonate biomineralization. However, in spite of multiple physical and biochemical characterizations, the explicit role of saccharide macromolecules (long chains of carbohydrate molecules) in mineral deposition is not yet understood. In this study, we investigated the influence of two common acidic monosaccharides (MSs), the two simplest forms of acidic carbohydrates, namely glucuronic and galacturonic acids, on the formation of calcite crystals in vitro.

Intramolecular Cross-Linking: Addressing Mechanochemistry with a Bioinspired Approach.

Many of the attractive properties in polymers are a consequence of their high molecular weight and therefore, scission of chains due to mechanochemistry leads to deterioration in properties and performance. Intramolecular cross-links are systematically added to linear chains, slowing down mechanochemical degradation to the point where the chains become virtually invincible to shear in solution. Our approach mimics the immunoglobulin-like domains of Titin, whose structure directs mechanical force towards the scission of sacrificial intramolecular hydrogen bonds, absorbing mechanical energy while unfolding.