A type of highly exfoliated, dispersed, and oriented organic montmorillonite filled polyimide (DABPI/OMMT) nanocomposites has been prepared successfully via in situ polymerization. Compared with the pristine DABPI, the DABPI/OMMT nanocomposites exhibit much better barrier and thermal performance. The water vapor permeability and oxygen permeability of DABPI/OMMT (5 wt%) are low to 0.31 g mil m−2 day−1 and 0.72 cm3 mil m−2 day−1, respectively. Meanwhile, its 5% weight‐loss temperature and coefficient of thermal expansion are 568°C and −1.1 ppm K−1, respectively. The results of transmission electron microscopy, 1D and 2D wide angle X‐ray diffractograms, as well as positron annihilation lifetime spectroscopy reveal that the excellent barrier and thermal performance of DABPI/OMMT (5 wt%) are mainly because of the high orientation of OMMT, increased crystallinity and low free volume of DABPI matrix. These are resulted from the “dual‐plane” structure effect, which is the synergistic orientation effect between the rigid planar molecular chains of DABPI and nanoplatelets of OMMT. POLYM. COMPOS., 39:E1725–E1732, 2018. © 2017 Society of Plastics Engineers

Fe2O3/attapulgite desulfurizer was prepared by impregnation, and was regenerated by use of heat air method. The desulfurization test from a gas containing 100 vol% H2S was carried out over attapulgite supported Fe2O3 in a fixed-bed system at atmospheric pressure and room. The effects of the chemical nature of Fe2O3 on desulfurization capacity were studied. Materials before and after the desulfurization test were characterized using FTIR and XRD. Materials after the regeneration test were characterized using XRD. The characterization results suggest that modification process does not change the structure of attapulgite. Iron species disperses inside channels and the outside surface in the crystalline phase of iron oxide. The material with iron oxide content of 40.0 wt% presented highest H2S uptake capacity. The deactivated that Fe2O3/attapulgite desulfurizer was regenerated 0.8L/min hot air in 323k, the regeneration efficiency reached 81.22%, by 4 times after regeneration can reach 51.9%.

Two sequence-inversed probes were microarrayed on glass slides to study the hybridization efficiency with their DNA targets. A fluorescence laser scanner and an atomic force microscope (AFM) were utilized to investigate the efficiency in different hybridization cases and their corresponding depth changes on the chips. The sequences of two targets were designed to be fully complementary to their shared DNA probe in a coaxial stacking configuration. In other words, after the first DNA target is hybridized (pre-hybridizing) onto the probe, the second one is stacked onto the non-hybridized region of the same probe. The pre-hybridizing and the second DNA targets were distinguished by two distinct fluorescent dyes. The enhancement of the hybridization efficiency was investigated through the comparison between the stacking and individual hybridization configurations. AFM was used to measure the depths of two probes at different steps of hybridization. The results indicated that the depths increased as the hybridization proceeded. Probe#1, pre-hybridizing close to the chip surface, obtained a thicker depth than the other probe pre-hybridizing away from the chip surface, Probe#2. A hypothesis was proposed to explain how the depth variation was associated with the observed hybridization efficiency.