CO Adsorption Enhanced by Tuning the Layer Charge in a Clay Mineral.

Due to the compact two-dimensional interlayer pore space and the high density of interlayer molecular adsorption sites, clay minerals are competitive adsorption materials for carbon dioxide capture. We demonstrate that with a decreasing interlayer surface charge in a clay mineral, the adsorption capacity for CO increases, while the pressure threshold for adsorption and swelling in response to CO decreases. Synthetic nickel-exchanged fluorohectorite was investigated with three different layer charges varying from 0.

Distributed Electric Field Induces Orientations of Nanosheets to Prepare Hydrogels with Elaborate Ordered Structures and Programmed Deformations.

Living organisms use musculatures with spatially distributed anisotropic structures to actuate deformations and locomotion with fascinating functions. Replicating such structural features in artificial materials is of great significance yet remains a big challenge. Here, a facile strategy is reported to fabricate hydrogels with elaborate ordered structures of nanosheets (NSs) oriented under a distributed electric field.

Light-steered locomotion of muscle-like hydrogel by self-coordinated shape change and friction modulation.

Many creatures have the ability to traverse challenging environments by using their active muscles with anisotropic structures as the motors in a highly coordinated fashion. However, most artificial robots require multiple independently activated actuators to achieve similar purposes. Here we report a hydrogel-based, biomimetic soft robot capable of multimodal locomotion fueled and steered by light irradiation.

Layer charge robust delamination of organo-clays.

To date delamination of organo-clays is restricted to highly charged, vermiculite-type layered silicates (-butylammonium vermiculites) while - counterintuitively - low charged, smectite-type layered silicates do not delaminate although their Coulomb interactions are much weaker. Guided by previous findings, we now identified organo-cations that allowed for extending the delamination of organo clays to charge densities in the regime of low charged smectites as well. Upon intercalation of protonated amino-sugars like -methyl-d-glucamine (meglumine) robust delamination of 2 : 1 layered silicates repulsive osmotic swelling in water is achieved.

Onset of Osmotic Swelling in Highly Charged Clay Minerals.

Delamination by osmotic swelling of layered materials is generally thought to become increasingly difficult, if not impossible, with increasing layer charge density because of strong Coulomb interactions. Nevertheless, for the class of 2:1 layered silicates, very few examples of delaminating organo-vermiculites were reported in literature. We propose a mechanism for this repulsive osmotic swelling of highly charged vermiculites based on repulsive counterion translational entropy that dominates the interaction of adjacent layers above a certain threshold separation.

Two-Step Delamination of Highly Charged, Vermiculite-like Layered Silicates via Ordered Heterostructures.

Because of strong Coulomb interactions, the delamination of charged layered materials becomes progressively more difficult with increasing charge density. For instance, highly charged sodium fluorohectorite (NaMgLiSiOF, Na-Hec) cannot be delaminated directly by osmotic swelling in water because its layer charge exceeds the established limit for osmotic swelling of 0.55 per formula unit SiOF.

Structural Insights into Water-Based Spider Silk Protein-Nanoclay Composites with Excellent Gas and Water Vapor Barrier Properties.

Nature reveals a great variety of inorganic-organic composite materials exhibiting good mechanical properties, high thermal and chemical stability, and good barrier properties. One class of natural bio-nanocomposites, e.g.