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Wu X.,Institute of Chemical Engineering | Wu X.,Qingdao University of Science and Technology | Zhang B.,Qingdao University of Science and Technology | Hu Z.,Qingdao University of Science and Technology
Materials Letters | Year: 2013

In this study, we successfully established an additive-free microwave hydrothermal (M-H) route by only using Al2(SO4) 3 aqueous solution and urea as raw materials. Core-shell structured boehmite was synthesized at 180°C for the first time via a M-H route. The final product was characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). On account of the fact that less reaction time usually means less energy consumption or more eco-friendly design, the M-H reaction time was successfully reduced to only 40 min by utilizing full microwave heating power and appropriate dosage of urea. To investigate the possible mechanism and influencing factors associated with the morphology and crystal form evolution process, samples subjected to different reaction durations were prepared and characterized. © 2012 Elsevier B.V. All rights reserved. Source


Wu X.,Institute of Chemical Engineering | Wu X.,Qingdao University of Science and Technology | Zhang B.,Qingdao University of Science and Technology | Hu Z.,Qingdao University of Science and Technology
Powder Technology | Year: 2013

An additive-free hydrothermal approach has been developed for the large-scale synthesis of lamellar morphology boehmite powders by merely using Al(NO3)3 and urea as raw materials conducted in an autoclave of 10L capacity. The hydrothermal synthetic and calcined products were characterized by techniques of X-ray diffraction(XRD), transmission electronic microscopy(TEM), scanning electron microscope(SEM), Fourier transform infrared spectrometry (FTIR) and thermogravimetric analysis (TGA/DTA). The microscope analysis manifested that the lamellar boehmite was around 100-200nm in width and 500-1000nm in length. The opportune influence factors on boehmite morphology, such as dosage of urea and reaction temperature were determined by single-factor experiment method. To investigate its crystal form and lamellar morphology evolution process, samples subjected to different reaction durations from 2h to 12h were prepared and characterized by techniques of TEM, SEM and XRD. A spontaneous morphology evolution mechanism driven by Ostwald ripening was proposed based on the experimental facts. © 2013 Elsevier B.V. Source


Wu X.,Institute of Chemical Engineering | Wu X.,Qingdao University of Science and Technology | Zhang B.,Qingdao University of Science and Technology | Hu Z.,Qingdao University of Science and Technology
Materials Letters | Year: 2012

The boehmite (γ-AlOOH) hollow microspheres were synthesized after 120 min reaction time at 150°C for the first time via a microwave hydrothermal route, using Al 2(SO 4) 3 aqueous solution and urea as raw materials and amphiphilic copolymer of P(St)-b-P(HEA) as structure-directing agent. The final product was characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). The microscope analysis revealed that the boehmite (γ-AlOOH) hollow microspheres were around 1-2 μm in diameter and a shell thickness of approximately 200 nm. To investigate the influencing factors and formation mechanism of the as-obtained boehmite hollow microspheres ultra-fine powders, samples subjected to different reaction durations were also studied by SEM. A self-assembly morphology evolution mechanism was proposed based on the experimental facts. © 2011 Elsevier B.V. All rights reserved. Source


Wu X.,Institute of Chemical Engineering | Wu X.,Qingdao University of Science and Technology | Zhang B.,Qingdao University of Science and Technology | Wang D.,Qingdao University of Science and Technology | Hu Z.,Qingdao University of Science and Technology
Materials Letters | Year: 2012

Boehmite (γ-AlOOH) hollow microspheres were synthesized via a convenient hydrothermal route. To investigate its crystal form and morphology formation process, samples subjected to different reaction durations from 1 to 24 h were prepared and characterized by techniques of X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope (SEM). A spontaneous morphology evolution mechanism driven by Ostwald ripening and dissolution-renucleation was proposed based on the experimental facts. We think that systematically understanding and hereby manipulating the morphology evolution process will contribute to fabricate novel morphologies of the materials. © 2011 Elsevier B.V. All rights reserved. Source


Kubicek C.P.,Austrian Institute of Industrial Biotechnology | Kubicek C.P.,Institute of Chemical Engineering
Journal of Biotechnology | Year: 2013

Recent progress and improvement in "-omics" technologies has made it possible to study the physiology of organisms by integrated and genome-wide approaches. This bears the advantage that the global response, rather than isolated pathways and circuits within an organism, can be investigated (" systems biology"). The sequencing of the genome of Trichoderma reesei (teleomorph Hypocrea jecorina), a fungus that serves as a major producer of biomass-degrading enzymes for the use of renewable lignocellulosic material towards production of biofuels and biorefineries, has offered the possibility to study this organism and its enzyme production on a genome wide scale. In this review, I will highlight the use of genomics, transcriptomics, proteomics and metabolomics towards an improved and novel understanding of the biochemical processes that involve in the massive overproduction of secreted proteins. © 2012 Elsevier B.V. Source

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