Search

We proved that ice crystallized from water molecules within as-synthesized graphene oxide (GO) can be used as a spacer among individual GO sheets to form an expanded GO aerogel with a three-dimensional porous network structure. This designed specific structure can be retained during further processes to form graphene paper. Due to the fact that the as-fabricated graphene paper contains carbon defects and space in its infrastructure, this creates more electroactive surfaces and interfaces to significantly increase the Faradaic reaction efficiency. With the introduction of redox-electrolyte K3Fe(CN)6 into a KOH electrolyte, we can obtain a 95-fold increase in the specific capacitance compared with the value obtained in the traditional KOH electrolyte. The ice-crystallization formed graphene paper electrode showed high electroactivity because the specific porous structure can favor the fast transfer of electrolyte ions, such as Fe(CN)63- ions. The presented results prove that ice-crystallization formed GO can serve as a chemically tunable platform for electrochemical energy storage applications. [ABSTRACT FROM AUTHOR]

The SlipChip is a microfluidic device designed to perform multiplexed microfluidic reactions without pumps or valves. The device has two plates in close contact. The bottom plate contains wells preloaded with many reagents; in this paper plates with 48 reagents were used. These wells are covered by the top plate that acts as a lid for the wells with reagents. The device also has a fluidic path, composed of ducts in the bottom plate and wells in the top plate, which is connected only when the top and bottom plate are aligned in a specific configuration. Sample can be added into the fluidic path, filling both wells and ducts. Then, the top plate is “slipped”, or moved, relative to the bottom plate so the complementary patterns of wells in both plates overlap, exposing the sample-containing wells of the top plate to the reagent-containing wells of the bottom plate, and enabling diffusion and reactions. Between the two plates, a lubricating layer of fluorocarbon was used to facilitate relative motion of the plates. This paper implements this approach on a nanoliter scale using devices fabricated in glass. Stability of preloaded solutions, control of loading, and lack of cross-contamination were tested using fluorescent dyes. Functionality of the device was illustrated viacrystallization of a model membrane protein. Fabrication of this device is simple and does not require a bonding step. This device requires no pumps or valves and is applicable to resource-poor settings. Overall, this device should be valuable for multiplexed applications that require exposing one sample to many reagents in small volumes. One may think of the SlipChip as an easy-to-use analogue of a preloaded multi-well plate, or a preloaded liquid-phase microarray. [ABSTRACT FROM AUTHOR]

Here we report a study on controlling the shape of particles by regulating the diffusion of chemicals. To change the diffusion rate of the reactive ions, we used a designed three-cell reactor in which the reactive ions were separated by porous membranes. We studied the reduction of hexachloroplatinate ions by sodium borohydride as an example. The experimental results show that control of the chemical diffusion led to the platinum product changing from cubic particles to dendritic particles. Further analysis indicates that the cubic particles were formed by the classic crystallization process via layer-wise deposition, while the dendritic particles were formed by the non-classic crystallization process through cluster aggregation. The control over the chemical diffusion prolongs the nucleation period and produces nuclei continuously, facilitating the aggregation of nuclei, which leads to the crystallization switching from the classic model to the non-classic model. The obtained results in this paper suggest that control over the chemical diffusion is a green and promising process to manipulate the structures of materials. [ABSTRACT FROM AUTHOR]

In this paper, we have built up the organic-inorganic hybrid co-crystal (1) by using the derivative of ethylenediammonium cations (N,N,N′,N′-tetra-p-methoxybenzyl-ethylenediamine, L1) and [CuCl4]2−anions. The reaction was carried out by mixing MeOH solution of CuCl2·2H2O and HCl/MeOH solution of L1at room temperature. Two types of inclusion compounds can be formed when using different guest molecules. When guest molecules, such as anthracene or phenanthrene, were included, it resulted in the formation of interlayered structures: anthracene ⊂ [H2L1]2+·[CuCl4]2−(2) and phenanthrene ⊂ [H2L1]2+·[CuCl4]2−(3). When β-naphthyl phenol were included, it led to the formation of pillared-layered complexes of [1-chloride-β-naphthyl phenol]1.0·[β-naphthyl phenol]0.5·[methanol]1.0⊂ 2[H2L1]2+·2Cl−·[CuCl4]2−(4). [ABSTRACT FROM AUTHOR]