A facile synthesis route for preparing SBA-15 silica of platelet shape and very short mesochannels (150-350 nm) was developed by introducing a small amount of Zr(IV) ions in the synthesis solution.The synthesis route can be easily extended to prepare platelet SBA-15 materials with various organic functional groups up to 1.87 mmol/g loading in one pot. In situ XRD and freeze-fracture replication TEM were found to be powerful techniques for studying the self-assembly processes. The platelet SBA-15 with short mesochannels in 150-350 nm was formed because of the fast self-assembly rate of P123 micelles and TEOS accelerated by the Zr(IV) ions in the synthesis solution. The platelet SBA-15 materials are superior to the conventional SBA-15 of rod or fiber morphologies in facilitating molecular diffusion and less possibility of pore blockage when used in the sorption or reactions of bulky molecules.

Thermally induced shape memory is an attractive feature of certain functional materials. Among the shape memory polymers, shape memory elastomers (SMEs) especially those with biodegradability have great potential in the biomedical field. In this study, we prepared waterborne biodegradable polyurethane SME based on poly(ε-caprolactone) (PCL) oligodiol and poly(l-lactic acid) (PLLA) oligodiol as the mixed soft segments. The ratio of the soft segments in polyurethanes was optimized for shape memory behavior. The thermally induced shape memory mechanism of the series of polyurethanes was clarified using differential scanning calorimeter (DSC), X-ray diffraction (XRD), and small-angle X-ray scattering (SAXS). In particular, the in situ SAXS measurements combined with shape deformation processes were employed to examine the stretch-induced (oriented) crystalline structure of the polyurethanes and to elucidate the unique mechanism for shape memory properties. The polyurethane with optimized PLLA crystalline segments showed a diamond-shape two-dimensional SAXS pattern after being stretched, which gave rise to better shape fixing and shape recovery. The shape memory behavior was further tested in 37 °C water. The biodegradable polyurethane comprising 38 wt % PCL segments and 25 wt % PLLA segments and synthesized at a relatively lower temperature by the waterborne procedure showed ∼100% shape recovery in 37 °C water. The biodegradable polyurethane SME also demonstrated good endothelial cell viability as well as low platelet adhesion/activation. We conclude that the waterborne biodegradable polyurethane SME possesses a unique thermally induced shape memory mechanism and may have potential applications in making shape memory biodegradable stents or scaffolds.

At the National Synchrotron Radiation Research Center, a small/wide‐angle X‐ray scattering (SAXS/WAXS) instrument has been installed at the BL23A beamline with a superconducting wiggler insertion device. This beamline is equipped with double Si(111) crystal and double Mo/B4C multilayer monochromators, and an Si‐based plane mirror that can selectively deflect the beam downwards for grazing‐incidence SAXS (GISAXS) studies of air–liquid or liquid–liquid interfaces. The SAXS/WAXS instrument, situated in an experimental hutch, comprises collimation, sample and post‐sample stages. Pinholes and slits have been incorporated into the beam collimation system spanning a distance of ∼5 m. The sample stage can accommodate various sample geometries for air–liquid interfaces, thin films, and solution and solid samples. The post‐sample section consists of a 1 m WAXS section with two linear gas detectors, a vacuum bellows (1–4 m), a two‐beamstop system and the SAXS detector system, all situated on a motorized optical bench for motion in six degrees of freedom. In particular, the vacuum bellows of a large inner diameter (260 mm) provides continuous changes of the sample‐to‐detector distance under vacuum. Synchronized SAXS and WAXS measurements are realized via a data‐acquisition protocol that can integrate the two linear gas detectors for WAXS and the area detector for SAXS (gas type or Mar165 CCD); the protocol also incorporates sample changing and temperature control for programmable data collection. The performance of the instrument is illustrated via several different measurements, including (1) simultaneous SAXS/WAXS and differential scanning calorimetry for polymer crystallization, (2) structural evolution with a large ordering spacing of ∼250 nm in a supramolecular complex, (3) SAXS for polymer blends under in situ drawing, (4) SAXS and anomalous SAXS for unilamellar lipid vesicles and metalloprotein solutions, (5) anomalous GISAXS for oriented membranes of Br‐labeled lipids embedded with peptides, and (6) GISAXS for silicate films formed in situ at the air–water interface.