Materials having both magnetic and catalytic properties have shown great potential for practical applications. Here, a reduced graphene oxide/iron oxide/silver nanohybrid (rGO/Fe3O4/Ag NH) ternary material was prepared by green synthesis of Ag on pre‐synthesized rGO/Fe3O4. The as‐prepared rGO/Fe3O4/Ag NH was characterized using Fourier transform infrared spectroscopy, X‐ray diffractometry, Raman spectroscopy, vibrating sample magnetometry, transmission electron microscopy and energy‐dispersive X‐ray spectroscopy. rGO sheets were covered with Fe3O4 (8–16 nm) and Ag (18–40 nm) nanoparticles at high densities. The mass percentages were 13.47% (rGO), 62.52% (Fe3O4) and 24.01% (Ag). rGO/Fe3O4/Ag NH exhibited superparamagnetic behavior with high saturated magnetization (29 emu g−1 at 12 kOe), and efficiently catalyzed the reduction of 4‐nitrophenol (4‐NP) with a rate constant of 0.37 min−1, comparable to those of Ag‐based nanocatalysts. The half‐life of 4‐NP in the presence of rGO/Fe3O4/Ag NH was ca 1.86 min. rGO/Fe3O4/Ag NH could be magnetically collected and reused, and retained a high conversion efficiency of 94.4% after the fourth cycle. rGO/Fe3O4/Ag NH could potentially be used as a magnetically recoverable catalyst in the reduction of 4‐NP and environmental remediation.

In this paper, the structural characteristics of the modified celluloses from acacia pulp in Vietnam were investigated and compared to other pulps. The total crystalline index (TCI), the lateral order index (LOI) and the hydrogen bond intensity (HBI) were evaluated by the FTIR spectra. The size of crystallites was considered by XRD patterns. Peak separations were carried out using Gaussian deconvolution for the band at 3700 -3000 cm -1 of the FTIR spectra and the XRD spectra. The results show that the TCI, LOI and HBI of modified acacia cellulose I are found to be around 1.09, 2.22 and 2.33, respectively, and the TCI, LOI, HBI of acacia cellulose II are found to be around 1.09, 1.51, 2.06, respectively. The crystalline size of modified acacia cellulose I is found to be as follows L(101) ~ 4.33 nm, L(101 ) ~ 8.58 nm and L(002) ~ 4.80 nm, and that of cellulose II is found to be as follows: L(101) ~ 4.04 nm, L (101 ) ~ 3.55 nm and L(002) ~ 2.99 nm.

The article presents results of effect of factors comprising the types of irradiation, the concentration of NR solution and the content of hydroperoxide in mixture on photochemical depolymerization of natural rubber. The results showed that the ultraviolet irradiation from the vapor mercury lamps (HSW-250W and HSW-125W) caused the faster rate of depolymerization than the light from  HF-500W; increasing concentration of NR in toluene leaded to decrease the rate of depolymerization; and as the content of hydroperoxide increased the rate of depolymerization was faster. Additionally, the IR spectra, 13C-NMR of products were determined and showed that the cis-1,4-isoprene structure has not been changed and there was the presence of hydroxyl-terminated groups and a few epoxy groups in chains.

Plastic explosive (PBX) is an explosive that a polymer binder is used to reduce the sensitivity of high explosives for various applications. This paper presents the characteristics of the PBXs based on liquid natural rubber (LNR) and hexogen (RDX). The PBXs are prepared according to a modified formulation of the Composition C-4. The plasticity of the PBXs is determined according to the MIL-STD-650 method 211.1. The uniaxial compression of the PBXs examined by the STANAG 4443. The test of the sensitivity of PBXs to friction is carried out by STANAG 4487. The thermal stability is tested by the STANAG 4556 at 100 oC for 40 hours. The results indicated that the plasticity is found to be more than 0.018 in accordance with the MIL-C-45010A. Further, the modulus of elasticity, yield strength, and strain can be adjusted by the composition of the LNR binder. In addition, the frictional sensitivity of the PBXs is significantly reduced to more 360 N of the load. The thermal stability is in the range of 0.156 to 0.225 ml.g-1 and completely meets technical requirements. Therefore, the direction of using LNR as a binder for PBXs gives acceptable results for further researches.

To date, determining with high accuracy the optical parameters (extinction coefficient k and refractive index n) of a slab from the sole transmittance data requires an inverse method based on numerical iteration procedures. In this paper, we propose a new inverse analytical method of extracting ( k, n) without numerical iterative processes. The high accuracy of this new inverse method is assessed, and as an application example, the optical parameters of CaF2 and Si substrates are determined in the IR spectral range of 4–8 µm.