The grazing incidence small-angle X-ray scattering (GISAXS) from structures within a thin film on a substrate is generally a superposition of the two scatterings generated by the two X-ray beams (reflected and transmitted beams) converging on the film with a difference of twice the incidence angle (α i) of the X-ray beam in their angular directions; these two scatterings may overlap or may be distinct, depending on α i. The two scatterings are further distorted by the effects of refraction. These reflection and refraction effects mean that GISAXS is complicated to analyze. To quantitatively analyze GISAXS patterns, in this study we derived a GISAXS formula under the distorted wave Born approximation. We applied this formula to the quantitative analysis of the GISAXS patterns obtained for various compositions of polystyrene-b-polyisoprene (PS-b-PI) diblock copolymer thin films on silicon substrates with native oxide layers. This analysis showed that the diblock copolymer thin films consist of hexagonally packed cylinder (HEX) structures, hexagonally perforated layer (HPL) structures, and gyroid structures, all with characteristic preferential orientations, depending on the composition of the copolymer. This is the first report of GISAXS studies of HEX, HPL, and gyroid microdomain structures in block copolymer thin films. Moreover, our study also provides a simple method for understanding GISAXS patterns and for determining the structure factor or interference function from them. Thus, the use of the GISAXS technique with our derived GISAXS formula as a data analysis engine is a very powerful tool for determining the morphologies of polymer thin films on substrates.

Monodisperse spherical Ni nanoparticles with diameters of 2 nm, 5 nm, and 7 nm were synthesized from the thermal decomposition of a Ni–oleylamine complex. Ni nanocrystal superlattices were generated via the controlled evaporation of solvent (see Figure). The nanoparticles were successfully used as catalysts for the Suzuki coupling reaction, and were readily oxidized to produce NiO nanoparticles.

The molecular ordering of aqueous conducting polymers is controlled using a rational method. By introducing various ionic liquids, which have designed electrostatic interactions to PEDOT:PSS solutions, the evolution of the molecular ordering of the PEDOT is manipulated. Consequently, highly ordered nanostructures are achieved with a reduced π-π stacking distance of ≈3.38 Å and, thus, a maximum σ of ≈2100 S cm .

The first in-situ two-dimensional grazing incidence small-angle X-ray scattering (2D GISAXS) study on the evolution of nanopores during the thin film formation of porous dielectrics from composite films is reported. A soluble poly(methylsilsesquioxane) (PMSSQ) precursor and a four-armed poly( -caprolactone) (PCL4) were chosen as the model matrix and porogen components within the composite film. The measured 2D GISAXS data were analyzed quantitatively using a GISAXS formula derived under the distorted wave Born approximation. It is shown that in-situ GISAXS is a powerful tool for monitoring the evolution of nanopores in dielectric thin films, providing structural characteristics such as size, size distribution, shape, electron density, and porosity, all as a function of temperature and time. In addition, the mechanism for forming imprinted nanopores in the dielectric films by sacrificial thermal degradation of the porogen was determined by in-situ GISAXS analysis. Phase separation of the PCL4 porogen was induced below 200 °C by cross-linking of the PMSSQ precursor matrix during thermal curing. This process generated porogen aggregates, each individually imprinted pore in the film through thermal degradation; the shape, size, and size distribution of the porogen aggregates are directly reflected in the dimensions of the imprinted pores. Moreover, it was found that higher porogen loadings caused larger porogen aggregates with a greater size distribution. The present results thus show that the structural characteristics of nanopores imprinted within PMSSQ dielectric films are governed by the PCL4 porogen aggregates formed through curing of the PMSSQ precursor matrix.

Protein pores are highly specific in binding to chiral substrates and in catalysing stereospecific reactions, because their active pockets are asymmetric and stereoselective. Chiral binding materials from molecular-level pores with high specificity have not been achieved because of problems with pore deformation and blocking . A promising solution is the self-assembly of single sheets where all pores are exposed to the environment, for example as metal-organic frameworks , polymers or non-covalent aromatic networks, but, typically, the pores are distant from the internal cavities with chirality. Here, we report the synthesis of homochiral porous nanosheets achieved by the 2D self-assembly of non-chiral macrocycles, with open/closed pore switching. Pore chirality is spontaneously induced by a twisted stack of dimeric macrocycles. The porous 2D structures can serve as enantiomer sieving membranes that exclusively capture a single enantiomer in a racemic mixture solution, with uptake capacity greater than 96%. Moreover, the entrapped guests inside the pores can be pumped out by pore closing triggered by external stimuli. This strategy could provide new opportunities for controlled molecule release, as well as for artificial cells.