Single layered polysilicate kanemite (NaHSi2O5·3H2O) was allowed to react with alkyltrimethylammonium chloride solutions to form alkyltrimethylammonium–kanemite complexes. During the organic intercalation, the SiO2 layers in the complexes were condensed to form three-dimensional SiO2 networks. The calcined products of the complexes had micro pores 2–4 nm in diameter, and the surface areas were ca. 900 m2g−1. The pore size of the calcined products was altered with the variation in the alkyl-chain length of the alkyltrimethylammonium ions employed.

The ion exchange reaction of interlayer Naf ions of a layered polysilicate kanemite with alkyltrimethylammonium ions, followed by calcination, gives highly ordered mesoporous materials with a hexagonal array of uniform channels.

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The synthetic conditions of highly ordered and thermally stable mesoporous molecular sieves from a layered silicate kanemite are established. We divided the formation process of the mesoporous materials from kanemite into two elemental processes: i) exchange of Na+ in the interlayer of kanemite for alkyltrimethylammonium cations and ii) condensation of silicates and formation of a three dimensional silicate framework. Higher pH (over 11.5) at the cation-exchange process and the subsequent pH adjustment at 8.5 at the condensation process were best suited for the formation of mesoporous products with high regularity and thermal stability. Removal of partially dissolved kanemite during the cation-exchange process avoided the formation of amorphous materials as a by-product. Structures of some intermediate silicate/surfactant complexes supported the proposed folded sheets mechanism for the formation of the mesoporous molecular sieves. Syntheses by using alkyltrimethylammonium with different alkyl-chain lengths are also reported.

Recent developments in the study of the intercalation of organoammonium ions into layered silicates are reviewed. The new developments of the applications of the organoammonium-exchanged layered silicates include the selective adsorption of toxic compounds from water, the immobilization of photo and electroactive species to construct novel photo and electrofunctional materials, and the complexation with organic polymers for the enhancement of the mechanical properties. The conversion of the layered solids to three dimensional nanoporous solids with novel microstructures and adsorptive properties has also been successfully done. The novel controlled properties achieved by the modification with the adsorption of organoammonium ions open new opportunities to tailor the properties of the inorganic-organic nanostructured materials.

a) Thermal effect caused by illumination of a pump pulseThe photon energy of the pump pulses (0.89 eV) was below the lowest d-d transition in Fe 3+ ions (1.4 eV) 29 , leading to a virtual excitation. The pump fluence was 200 mJ/cm 2 .In our sample, the refractive index was 2.4, and the absorption coefficient was 0.3 cm -1 for the pump wavelength. Therefore, the absorbed pump fluence was less than 1 mJ/cm 2 , which enabled almost uniform excitation across the entire thickness of 110 μm.Considering that the specific heat is 0.4 J/g K and the density is 7 g/cm 3 , the instantaneous temperature increase caused by a pump pulse is calculated to be ~ 0.05 K.From the thermal conductivity (0.05 W/cm K), the heat diffusion length from a Gaussian spot with r 0 = 25 μm is calculated to be ~ 0.2 nm after 3 ns. Therefore, the thermal effect does not play a major role in our experiment with a spatial resolution of 20 μm. Indeed, the incoherent signal was not experimentally observed outside the pump spot. b) Theoretical modelLet us start with the Landau-Lifshitz equation for the unit magnetization vector ( ) ,t = m m r , where 2 1 = m . If the effective magnetic pulse field, ( , ) t h r , generated via the inverse Faraday effect is perpendicular to the sample surface, that is, ( , ) ( , , ) t h x y t = h r z , the Landau-Lifshitz equation takes the form effˆ[ ] ( ) ( , ) x y d m m h t dt γ γ = − × + − m m H y x r ,where eff H is the effective field, determined through the variation of the magnetic energy of the system with respect to magnetization; x , ŷ , and ẑ are unit vectors along the x, y, and z axes, respectively; and B g = /h γ μ ( 0 > ) is the gyromagnetic constant, where B μ is SUPPLEMENTARY INFORMATION

The degradation of colloidal mesoporous silica nanoparticles (CMPS) is quite important for the design of stable catalyst supports and biodegradable drug delivery systems carriers. The degradation of various silica nanoparticles in static aqueous systems was investigated. The condition was achieved through the use of a dialysis tube. Four types of CMPS with different particle diameters (ca. 20−80 nm) were newly prepared from tetraalkoxysilanes (Si(OR) 4 , R = Me, Et, Pr, and Bu) at different hydrolysis rates by a one-pot synthesis. Larger particles were formed by using tetraalkoxysilanes at slower hydrolysis rates because particle growth dominates nucleation. The degradation of CMPS is independent of diameter differences. The degradation rate of CMPS is higher than that of colloidal nonporous silica nanoparticles with smaller diameters because of the presence of mesopores. CMPS are also more degradable than aggregated CMPS because of colloidal dispersity. Moreover, it was confirmed for the first time that the degradation simultaneously proceeds from the outer as well as the inner surfaces of CMPS and that the mesostructure and morphology are partly retained even after more than half of the CMPS are degraded. The information on the degradation reported here is quite useful for the design of silica-based nanomaterials with tunable degradability/stability.

Coherent spin oscillations were nonthermally induced by circularly polarized pulses in the fully compensated antiferromagnet NiO. This effect is attributed to the action of the effective magnetic field generated by an inverse Faraday effect on the spins. The novelty of this mechanism is that spin oscillations are driven by the time derivative of the effective magnetic field which acts even on "pure" antiferromagnets with zero net magnetic moment in the ground state. The measured frequencies (1.07 THz and 140 GHz) correspond to the out-of-plane and in-plane modes of antiferromagnetic spin oscillations.