Based on ‘Mineral Plastics’, organic–inorganic hybrid hydrogels were synthesized by utilization of different metal ions and pH-values.

In the work presented here, free-barium activity was monitored during the barium sulfate crystallization and we identified for the first time (in the absence of additives) a metastable BaSO4 amorphous phase that precedes barite formation.

graded carbon nanocomposites, [14,15] magnetic particle gradients, [16,17] and metal nanoparticle gradients at surfaces. [18] Established preparation methods for poly meric gradient composites like centrifugal casting, [19] corona discharge, [20] photopolymerization, [21] selective laser sintering, [22,23] and 3D printing [24] lack the possibility to simulate the gradients in advance and/or to detect the nanoparticle concentration gradient during processing. Also, 3D printing leads to step and no continuous gradients.In contrast, we use analytical ultracentrifugation (AUC), a classical technique for polymer and colloid analytics, to fabricate a desired concentration gradient of nanoparticles in a gelatin matrix. The concentration gradient can be simulated in advance with the well-established thermodynamic theory of AUC [25] and detected any time by optical detection systems (interference and absorption). Depending www.advancedsciencenews.com

The concept of nanoparticles (NPs) as building blocks offers new possibilities to produce complex and tailored structures from the nano- to the mesoscale. In order to control a “polymerization” of particles, knowledge of the mechanism and kinetics of the reaction are necessary. We show that controlled assembly of cetylpyridinium chloride-stabilized gold NPs utilizing induced dipole–dipole interactions can lead to the formation of defined one-dimensional structures in solution. Three different shaped NPs (cubes, octahedra, and truncated cuboctahedra) were investigated individually. The assembly process is analogous to a step growth polymerization and is quantitatively describable with kinetics of a polyesterification. In situ kinetic studies reveal that there is an ideal particle size and shape for the induced dipole-driven assembly. Even small changes in size have remarkable effects on the assembly behavior. We further demonstrate that the transition from oriented assembly to oriented attachment requires a critical particle size (critical interface area) resulting from a size-dependent energy barrier for the crystallographic fusion. A combination of ideal size, shape, and degree of destabilization enables controlled oriented attachment of gold NPs in solution to chainlike structures under ambient conditions.