Multimode Self‐Oscillating Vesicle Transformers

Engineering synthetic materials that mimic the complex rhythmic oscillatory behavior of living cells is a fundamental challenge in science and technology. Up to now, the reported synthetic model system still cannot compete with nature in oscillatory modes and amplitudes. Presented here is a novel alternating copolymer vesicle that exhibits drastic and multimode shape oscillations in real time, which are controlled by polymer concentrations and driven by the Belousov—Zhabotinsky oscillatory reaction, including swelling/deswelling, twisting/detwisting, stretching/shrinking, fusion/fission, and multiple division. Some of them, especially the fission oscillation, have not been observed before. In addition, the oscillation magnitude with regard to diameter is much larger than that of previously reported self‐oscillating vesicles. Such a self‐oscillating vesicle transformer would extend the complexity and capacity of membrane deformations in synthetic systems, approaching those of natural cells.     

Mesoporous silica hybridized by ordered mesoporous carbon for in‐tube solid‐phase microextraction

To enhance the extraction performance, a mesoporous silica was modified with ordered mesoporous carbon for solid‐phase microextraction. Three stainless‐steel wires coated with the mesoporous material were placed in a polyetheretherketone tube for getting an extraction tube. The tube was coupled to high‐performance liquid chromatography with diode array detector, and the online analysis system was constructed. Then its extraction performance was evaluated using hydrophobic polycyclic aromatic hydrocarbons, phthalates, and hydrophilic neonicotinoids. The best selectivity was presented for polycyclic aromatic hydrocarbons. Several main conditions were optimized such as sampling volume, sampling rate, methanol concentration in the sample, and desorption time, a rapid and sensitive analytical method was established toward polycyclic aromatic hydrocarbons. The analytical method exhibited wide linear range from 0.017 to 15 µg/L with acceptable correlation coefficients more than 0.9990, limits of detection in 0.005‐0.020 µg/L, limits of quantification ranging from 0.017 to 0.066 µg/L as well as large enrichment factors of 377‐2314. It was successfully applied to detect trace polycyclic aromatic hydrocarbons in some real water samples including tap water, snow water, and domestic sewage.     

Ultrasound assisted eco-friendly synthesis of 3-cinnamoyl coumarins using N,N'-(1,2-phenylene)bis(2-aminobenzamide) dichloro cobalt immobilized on mesoporous Al-SBA-15 as a new and recyclable catalyst

ABSTRACT

A novel mesoporous Al-SBA-15 modified by N,N'-(1,2-phenylene)bis(2-aminobenzamide) dichloro cobalt has been prepared and applied as a reusable catalyst in the 3-cinnamoyl coumarins synthesis via three-component reaction between benzaldehydes, salicylaldehydes and ethyl acetoacetate by the assist of ultrasonic irradiation. By using of the nanocatalyst and also ultrasound irradiation, the easiness and velocity of the abovementioned reaction were enhanced and an environment friendly condition was provided to synthesis of various 3-cinnamoyl coumarin compounds. The properties and structure of nanocatalyst have been specified by methods including powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), nitrogen adsorption–desorption analysis and scanning electronic microscopy (SEM). Superiority of this novel and viable method is due to mild reaction condition, short reaction times, high yields of 3-cinnamoyl coumarins, environmentally benign, recoverability of the CoCl₂N,N'-(1,2-phenylene)bis(2-aminobenzamide)/Al-SBA-15 catalyst and reusability with important preservation in its catalytic activity.     

Recent Advances in Covalent Organic Frameworks for Catalysis

Covalent organic frameworks (COFs) as an emerging type of crystalline porous materials, have obtained considerable attention recently. They have exhibited diverse structure and attractive performance in various catalytic reactions. It is highly expected to have a systematic and comprehensive review summing up COFs‐derived catalysts in homogeneous and heterogeneous catalysis, which is favorable to the judicious design of an efficient catalyst for targeted reaction. Herein, we focus on summarizing recent and significant developments in COFs materials, with an emphasis on both the synthetic strategies and targeted functionalization, and categorize it in accordance with the different types of catalytic reactions. Their potential catalysis applications are reviewed thoroughly. Moreover, a personal view about the future development of COFs catalysts with respect to the large‐scale production is also discussed.     

Bio-inspired short peptide self-assembly: From particles to functional materials

Natural systems are typically featured with tremendous molecular complexity and construct exquisite architectures and functional materials through precise spatial and temporal control. Supramolecular self-assembly from peptides and proteins is believed to be the key player. Thus, knowledge of the fundamental mechanisms driving peptides into vast functional hierarchical structures will certainly help the rational control of self-assembly process, leading to more precise structural organization and functional optimization. In this review, we briefly summarize the recent progress of this burgeoning field mainly from two directions: peptide-based self-assembly and co-assembly with other functional molecules, each part is further divided into two subparts and representative examples are given for each subpart according to their development timeline. At the end of each part, brief summaries of the closely related applications are outlined. For the closing remarks, we conclude with our own understanding of the area and perspectives are given based on recent developments. Overall, this review could be suitable for both new readers to gain a comprehensive overview of the area and experienced readers to get a summary of the development in short peptide self-assembly from particles to functional materials.     

Radiophotolumenescence of Irradiated Polymethylmethacrylate Doped with Some Charge Transfer Complexes

Radiophotolumenescence (RPL) of irradiated and non irradiated thin films of polymethylmethacrylate (PMMA) doped with anthracene (Anth) as a donor, and tetracyanoquinodimethane (TCNQ) as an acceptor, has been investigated. The RPL – glow spectrum was recorded to study the characterizing emission bands from the point of view of glow peak position and intensity and hence the prospective relative sensitivities. RFL – signal fading after one month storage in dark at room temperature post gamma irradiation was also studied. PMMA doped with 6:4 donor to acceptor ratio has been proved to be the most sensitive one with less fading regarding gamma detection. On the other hand 2 Anth: 8 TCNQ was found to be the proper dopant concentration ratio for thermal neutron detection.     

Application of Autoradiography to the Investigation of New Doping Techniques of Semiconductor Materials

The development of technology of new semiconductor devices requires fundamental studies of a number of phenomena taking place in semiconductors during the doping process or accompanying the doping process.

These studies are concerned with the following problems:

1. Diffusion of gold in silicon and the effect of diffusion layers (particularly phosphorus layers) and epitaxial silicon layers on the distribution of gold in thin silicon plates.

2. Distribution of admixtures in silicon introduced with the aid of the ion implantation technique. Our studies concerned with the second of the above mentioned problems comprised an autoradiographic examination of the homogeneity of the beam of phosphorus ions implanted in silicon, and a study of some apparatus factors and of the purity of the basic material on the implantation.