分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Based on a bio-inspiration polydopamine reaction platform, hollow Ag/carbon microporous spheres were facilely prepared through a template-assisted method. The hollow Ag/carbon spheres, with a uniform shell thickness of 30 nm and a high Ag loading, show high catalytic activity for the reduction of 4-nitrophenol by NaBH4 to 4-aminophenol. It is found that the 4-nitrophenol (10 mL, 1 10 3 M) can be completely converted to 4-aminophenol in 2 min by adding 20 mg of hollow Ag/carbon catalysts. The catalytic activity of the hollow Ag/carbon microporous spheres is also confirmed by CO oxidation. At 200 C, 100% CO conversions can be achieved by using hollow Ag/carbon microporous spheres as catalysts, which is promising to replace other noble metal catalysts in metal catalyzed reactions.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: hrough bio-inspired polydopamine modification of the ceramic support surface, dense and reproducible zeolitic imidazolate framework (ZIF) membranes have been developed for the first time for seawater desalination by pervaporation. Demonstrated by both experimental and simulation studies, the developed ZIF membranes show high desalination performances attributing to the small pore size of the ZIF membranes, which is exactly in between the size of water molecules and hydrated ions. The ZIF membranes show a high stability in seawater. At 25, 50, 75 and 100 °C, the water fluxes through the ZIF-8 membrane are 5.8, 8.1, 10.8, and 13.5 kg/(m2·h), re- spectively, with a high ion rejection of over 99.8%, which is promising for seawater desalination by ionic sieving.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: A superhydrophobic zeolitic imidazolate framework (ZIF-90) with high steam stability is prepared through post-functionalization via an amine condensation reaction. The developed superhydrophobic ZIF-90 is highly promising as an effective and reusable adsorbent for bio-alcohol recovery.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: It is well known that zeolite LTA membranes have poor acid resistance although they have been considered the best hydrophilic zeolite membranes for the dehydration of organic aqueous mixtures. In the present work, we develop a simple and effective road to enhance the acidic stability of the zeolite LTA membrane through the depositing of a graphene oxide (GO) layer as an acid-resisting barrier on the surface of the zeolite LTA membrane. A relatively thin (about 5.5 mm) but dense and firm LTA@GO composite membrane is obtained by using dopamine as a covalent linker between the zeolite LTA and GO layers. The presence of the protective GO layer effectively inhibits the degradation of the zeolite LTA membrane by acetic acid, which greatly enhances its acid-resistant stability, leading to a high selectivity and stability for the dehydration of acetic acid. For the separation of 95 wt% acetic acid/water mixture at 333 K, the separation factor and flux of the LTA@GO composite membrane are about 400 and 1.5 kg m 2 h 1, respectively, and keep almost constant for 168 h.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: With global appeal to green and efficient utilization of energies, metal-organic frameworks based mixed matrix membranes are standing out in applications such as gas and liquid separation because of the integration of size/shape selectivity of MOFs with p
提交时间: 2017-05-02
摘要: Through layer-by-layer [LBL] deposition of a graphene oxide [GO] suspension on a semicontinuous ZIF-8 layer, we have developed a novel bicontinuous ZIF-8@GO membrane. Since only the gaps between the ZIF-8 crystals are sealed by the GO layer due to capilla