Large, monodisperse core-shell Au-Ag nanoparticles with Ag-like optical properties have been prepared by the seeding growth method in micellar media.

No abstract

Metal organic frameworks (MOFs) have promising application prospects in the field of hydrogen storage. However, the successful application of MOFs in the field is still limited by their hydrogen storage capacity. Herein, a series of M x M 1– x ( BDC )TED 0.5 (M = Zn, Cu, Co, or Ni) with a bimetallic structure was constructed by introducing two metal ions in the synthesis process. The results of X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma showed that the bimetallic structure with different content ratios can be stably constructed by a hydrothermal method. Among them, the Cu-based bimetal MOFs Cu 0.625 Ni 0.375 (BDC)TED 0.5 exhibited the best hydrogen storage capacity of 2.04 wt% at 77 K and 1 bar, which was 22% higher than that of monometallic Ni( BDC )TED 0.5 . The enhanced hydrogen storage capacity can be attributed to the improved specific surface area and micropore volume of bimetal MOFs by introducing an appropriate amount of bimetallic atoms.

Owing to their large specific surface areas and excellent heat and mass transfer compared with those of conventional batch reactors, microreactors have been widely used in chemical industries. In this study, a strategy is proposed for precisely controlling the synthesis of comb-type terpolymers in a microreactor. Poly(octadecyl acrylate− docosyl acrylate−maleic anhydride) was investigated as a pour point depressant (PPD) for waxy crude oils. A terpolymer showing a high weight-average molecular weight (M w ) and low polydispersity index (PDI) was synthesized within 5 min compared with a conventional time-consuming batch reaction. Under the optimal conditions, the M w of the terpolymer reached 3.7 × 10 4 , and the PDI was 1.42. Notably, the pour point of the crude oil was reduced by 8 K at a PPD dosage of 1300 ppm. The polymerization kinetics revealed that the microreactor accelerated the polymerization. In contrast to the batch reactor, the microreactor exhibited better heat transfer, which avoided the generation of hot spots. Furthermore, the calculated Bodenstein number (Bo) revealed that the degrees of plug-flow deviation and backmixing are negatively correlated with the molecular weight distribution.