Southwest University of Science and Technology

About: Southwest University of Science and Technology is a education organization based out in Mianyang, China. It is known for research contribution in the topics: Adsorption & Graphene. The organization has 10017 authors who have published 8923 publications receiving 94850 citations. The organization is also known as: Xīnán Kējìdàxué.

High-Performance Unidirectional Manipulation of Microdroplets by Horizontal Vibration on Femtosecond Laser-Induced Slant Microwall Arrays.

Abstract: The high-performance unidirectional manipulation of microdroplets is crucial for many vital applications including water collection and bioanalysis. Among several actuation methods (e.g., electric, magnetic, light, and thermal actuation), mechanical vibration is pollution-free and biocompatible. However, it suffers from limited droplet movement mode, small volume range (VMax /VMin < 3), and low transport velocity (≤11.5 mm s-1 ) because the droplet motion is a sliding state caused by the vertical vibration on the asymmetric hydrophobic microstructures. Here, an alternative strategy is proposed-horizontal vibration for multimode (rolling, bouncing/reverse bouncing, converging/diffusing, climbing, 90o turning, and sequential transport), large-volume-range (VMax /VMin ≈ 100), and high-speed (≈22.86 mm s-1 ) unidirectional microdroplet manipulation, which is ascribed to the rolling state on superhydrophobic slant microwall arrays (SMWAs) fabricated by the one-step femtosecond laser oblique ablation. The unidirectional transport mechanism relies on the variance of viscous resistance induced by the difference of contact area between the microdroplet and the slant microwalls. Furthermore, a circular, curved, and "L"-shaped SMWA is designed and fabricated for droplet motion with particular paths. Finally, sequential transport of large-volume-range droplets and chemical mixing microreaction of water-based droplets are demonstrated on the SMWA, which demonstrates the great potential in the field of microdroplet manipulation.

In Situ Adsorption of Mixed Anionic/Cationic Collectors in a Spodumene-Feldspar Flotation System: Implications for Collector Design.

Abstract: Herein, we investigated the effects of mixed collectors with varying alkyl chain lengths and ligand types on the hydrophobicity of the spodumene‒feldspar flotation system Various collector-mineral

CO2 Methanation over Supported Ru/Al2O3 Catalysts: Mechanistic Studies by In situ Infrared Spectroscopy

Abstract: Alumina supported ruthenium particles with an average diameter of 2 nm were prepared by a modified ethylene glycol reduction method. Catalytic methanation of CO2 over this catalyst was studied by in situ FTIR spectroscopy. After pretreatment in H2, different types of adsorbed species were detected on the catalyst surface at 200 °C. Based on a series of targeted experiments under variation of gas composition, order of addition, reaction time and temperature, a reaction scheme and the rate-determining steps of CO2 methanation are proposed. Two potential reaction paths for the hydrogenation of CO2 to form CH4 were identified: (I) CO adsorbed on the Ru metal surface acted as active intermediate and the CO methanation followed. The dissociation of CO to form surface carbon represents the rate-determining step. (II) Formyl species formed by hydrogenation of adsorbed CO2 are the active intermediate and the formation of formyl was the rate-determining step.

Biosorption behaviors of uranium (VI) from aqueous solution by sunflower straw and insights of binding mechanism

Abstract: Uranium (VI)-containing water has been recognized as a potential longer-term radiological health hazard. In this work, the sorptive potential of sunflower straw for U (VI) from aqueous solution was investigated in detail, including the effect of initial solution pH, adsorbent dosage, temperature, contact time and initial U (VI) concentration. A dose of 2.0 g L−1 of sunflower straw in an initial U (VI) concentration of 20 mg L−1 with an initial pH of 5.0 and a contact time of 10 h resulted in the maximum U (VI) uptake (about 6.96 mg g−1) at 298 K. The isotherm adsorption data was modeled best by the nonlinear Langmuir–Freundlich equation. The equilibrium sorption capacity of sunflower straw was observed to be approximately seven times higher than that of coconut-shell activated carbon as 251.52 and 32.37 mg g−1 under optimal conditions, respectively. The positive enthalpy and negative free energy suggested the endothermic and spontaneous nature of sorption, respectively. The kinetic data conformed successfully to the pseudo-second-order equation. Furthermore, energy dispersive X-ray, fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated that U (VI) adsorption onto sunflower straw was predominantly controlled by ion exchange as well as complexation mechanism. The study revealed that sunflower straw could be exploited for uranium remediation of aqueous streams as a promising adsorbent.

Preparation and characterization of activated carbon from Kraft lignin via KOH activation

Abstract: Kraft lignin (KL), which is largely obtained from Kraft pulping process, is typically utilized to generate steam, electricity, and heat. The huge amount of KL can also be utilized for various purposes such as producing biofuels, chemicals, and materials. In this work, industrial waste KL was used to prepare activated carbons (ACs) with high surface area and large pore volume via KOH activation method. The effects of pretreatment methods of KL, activation methods, and activation conditions on the pore structures and the yield of ACs were investigated. The prepared ACs were characterized by XRD, SEM, FTIR, and N2 adsorption at −196°C. The results showed that the pore structure and the yield of ACs were closely related to the various pretreatment methods, activation methods, and conditions. A 26% carbon yield of AC with the maximum BET surface area of 2762.5 m2/g and pore volume of 1.32 cm3/g was obtained under the following activation condition (a) KOH to acid pretreatment KL mass ratio of 4, (b) activation temperature of 750°C, (c) activation duration of 2 h, and (d) N2 flow rate of 160 cm3/min. The activating agent KOH can be recovered partially and the washing water discharge can also be minimized by reuse process. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 519–526, 2014