Facile Synthesis of Hierarchical Nanosized Single-Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single-crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8-rings), AEL (10-rings), AFI (12-rings), and -CLO (20-rings) topologies, ranging from small to extra-large pores, were synthesized. These materials show exceptional properties, including small crystallites (30–150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time-dependent study revealed a non-classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.     

Facile Synthesis of Hierarchical Nanosized Single‐Crystal Aluminophosphate Molecular Sieves from Highly Homogeneous and Concentrated Precursors

The synthesis of hierarchical nanosized zeolite materials without growth modifiers and mesoporogens remains a substantial challenge. Herein, we report a general synthetic approach to produce hierarchical nanosized single‐crystal aluminophosphate molecular sieves by preparing highly homogeneous and concentrated precursors and heating at elevated temperatures. Accordingly, aluminophosphate zeotypes of LTA (8‐rings), AEL (10‐rings), AFI (12‐rings), and ‐CLO (20‐rings) topologies, ranging from small to extra‐large pores, were synthesized. These materials show exceptional properties, including small crystallites (30–150 nm), good monodispersity, abundant mesopores, and excellent thermal stability. A time‐dependent study revealed a non‐classical crystallization pathway by particle attachment. This work opens a new avenue for the development of hierarchical nanosized zeolite materials and understanding their crystallization mechanism.     

有机化学品的生物降解性及构效关系

介绍了描述生物降解性的主要测定参数，测定过程的影响因素及常用的结构描述符，并结合实例综述了目前应用比较广泛的定量结构－生物降解性关系（QSBR）技术，最后，分析了QSBR工作存在的主要问题及研究前景。     

Emulsion inversion induced by CO2

Herein it was found that CO(2) could trigger an O/W to W/O emulsion inversion via a W/O/W nanoemulsion. In comparison with the conventionally used liquid or solid additives, the unusual advantage of this method is that the emulsion morphologies can be switched reversibly by the control of CO(2) pressure. Besides, CO(2) can be easily removed by depressurization and thus no extra separation process is needed, and CO(2) can be recycled. Furthermore, other lipophilic gases of ethylene, propylene and isobutane can also induce the O/W to W/O emulsion inversion. A possible mechanism for the gas-triggered emulsion inversion was proposed.     

Metastable gamma-MnS hierarchical architectures: synthesis, characterization, and growth mechanism

Preparation of shape-controlled metastable gamma-MnS semiconductor nanocrystals has been achieved on a large scale through a simple solvothermal method in the presence of PVP. The key strategy is the use of sulfur powder as sulfur source in ethylene glycol (EG) solvent that also acted as a weak reducing agent. Reaction parameters such as reaction time and temperature are found to be important in controlling various hierarchical architectures, such as homogeneous semi-hollow core-shell, hollow nanospheres, and nanowires. Transmission electron microscopy observations indicate that these hierarchical architectures are formed mainly via Ostwald ripening. The optical absorption measurements reveal that these novel architectures exhibit remarkable shift of absorption peak during the course of structural compaction and grain growth.     

Selective-controlled synthesis of one-dimensional strontium phosphates

Anorthic SrHPO₄ nanobelts and hexagonal Sr₁₀O(PO₄)₆ nanorods were obtained by a simple hydrothermal method without adding any surfactant as template. The as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). TEM and HRTEM observations of the products revealed that the as-prepared SrHPO₄ nanobelts and Sr₁₀O(PO₄)₆ hexagonal nanorods are single crystals with their preferential growth direction along the normal of (1 0 0) and (0 0 1) planes, respectively.     

Study on the photocatalytic degradation of methyl orange in water using Ag/ZnO as catalyst by liquid chromatography electrospray ionization ion-trap mass spectrometry

A nanocrystal catalyst Ag/ZnO was successfully synthesized using a simple solvothermal method in this study. This catalyst was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that this catalyst was composed of metallic Ag and ZnO. The photodegradation of methyl orange (MO) was investigated in aqueous suspension containing Ag/ZnO catalyst under UV irradiation. Liquid chromatography coupled with electrospray ionization ion-trap mass spectrometry was applied to the analysis of the samples coming from the photocatalytic degradation of MO. The experimental results showed that there were four intermediates existing in the photocatalytic reaction. MO could be mineralized in the Ag/ZnO suspension after 60 min illumination.