Fe2O3 and its composites have been extensively investigated and employed for the remediation of contaminated water with the characteristics of low cost, outstanding chemical stability, high ...efficiency of visible light utilization, excellent magnetic ability and abundant active sites for adsorption and degradation. In this review, the potentials of Fe2O3 in water remediation were discussed and summarized in detail. Firstly, various synthesis methods of Fe2O3 and its composites were reviewed and compared. Based on the structures and characteristics of the obtained materials, their applications and related mechanisms in pollutants removal were surveyed and discussed. Furthermore, several strategies for optimizing the remediation processes, including dispersion, immobilization, nano/micromotor construction and simultaneous decontamination, were also highlighted and discussed. Finally, recommendations for further work in the development of novel Fe2O3-related materials and its practical applications were proposed.
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•Synthesis methods of Fe2O3 materials are outlined and compared.•Applications and optimization strategies are summarized and discussed.•Mechanisms responsible for removing various pollutants are concluded.
Tumor metastasis is one of the big challenges in cancer treatment and is often associated with high patient mortality. Until now, there is an agreement that tumor invasion and metastasis are related ...to degradation of extracellular matrix (ECM) by enzymes. Inspired by the formation of natural ECM and the in situ self-assembly strategy developed in our group, herein, we in situ constructed an artificial extracellular matrix (AECM) based on transformable Laminin (LN)-mimic peptide 1 (BP-KLVFFK-GGDGR-YIGSR) for inhibition of tumor invasion and metastasis. The peptide 1 was composed of three modules including (i) the hydrophobic bis-pyrene (BP) unit for forming and tracing nanoparticles; (ii) the KLVFF peptide motif that was inclined to form and stabilize fibrous structures through intermolecular hydrogen bonds; and (iii) the Y-type RGD-YIGSR motif, derived from LN conserved sequence, served as ligands to bind cancer cell surfaces. The peptide 1 formed nanoparticles (1-NPs) by the rapid precipitation method, owing to strong hydrophobic interactions of BP. Upon intravenous injection, 1-NPs effectively accumulated in the tumor site due to the enhanced permeability and retention (EPR) effect and/or targeting capability of RGD-YIGSR. The accumulated 1-NPs simultaneously transformed into nanofibers (1-NFs) around the solid tumor and further entwined to form AECM upon binding to receptors on the tumor cell surfaces. The AECM stably existed in the primary tumor site over 72 h, which consequently resulted in efficiently inhibiting the lung metastasis in breast and melanoma tumor models. The inhibition rates in two tumor models were 82.3% and 50.0%, respectively. This in vivo self-assembly strategy could be widely utilized to design effective drug-free biomaterials for inhibiting the tumor invasion and metastasis.
Due to the exceptional characteristics which resulted from nanoscale size, such as improved catalysis and adsorption properties as well as high reactivity, nanomaterials have been the subject of ...active research and development worldwide in recent years. Numerous studies have shown that nanomaterials can effectively remove various pollutants in water and thus have been successfully applied in water and wastewater treatment. In this paper, the most extensively studied nanomaterials, zero-valent metal nanoparticles (Ag, Fe, and Zn), metal oxide nanoparticles (TiO2, ZnO, and iron oxides), carbon nanotubes (CNTs), and nanocomposites are discussed and highlighted in detail. Besides, future aspects of nanomaterials in water and wastewater treatment are discussed.
Recent progress of continuous crystallization Wang, Ting; Lu, Haijiao; Wang, Jingkang ...
Journal of industrial and engineering chemistry (Seoul, Korea),
10/2017, Volume:
54
Journal Article
Peer reviewed
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Continuous crystallization has always been a hot topic in industrial crystallization. Many efforts have been made to improve the continuous crystallization, either by designing novel ...continuous crystallizers or by proposing improved design and operation of conventional continuous crystallizers. Some new models for continuous crystallization processes have also been proposed and tested in recent years. In this work, the development of continuous crystallization in recent years, including novel crystallizers, control strategies, models and some assistive technologies, is summarized. Promising as it is, continuous crystallization is still not as universal as batch crystallization due to the existence of the drawbacks, such as blockage and encrustation. Therefore, further efforts are needed before wider application of continuous crystallization.
Continuous operation allows process conditions that are not attainable within batch crystallizers to be utilized. This in turn allows for product crystal attributes that are not possible in the ...equivalent batch crystallizations to be produced. In this study, the product crystal size distributions attainable from the anti-solvent crystallization of benzoic acid in plug flow, MSMPR and the equivalent fed batch and batch reverse addition crystallizations, were characterized. It was found that the continuous plug flow and MSMPR crystallizers were able to access crystal size distributions that are both smaller and larger than could be produced via the equivalent batch crystallizations, in addition to providing huge increases in productivity.
In-situ process analytical techniques (FBRM, ATR-FTIR) were employed to characterize each of these processes, including a calibration-free ATR-FTIR technique. Furthermore, a novel intermittent pneumatic MSMPR withdrawal method, which negated clogging/fouling of transfer lines, is demonstrated. It is hoped that the use of such techniques may facilitate the uptake of continuous processes in pharmaceutical crystallization where limitations on development time and concerns about slurry transport are perceived to be barriers to the implementation of this technology.
•Characterizes impact of crystallization dynamics of continuous and batch processes.•Comparison of MSMPR, plug flow and batch crystallizations.•Novel pneumatic slurry transfer strategy is outlined.•Application of in-situ PAT to continuous crystallzation design.
It is challenging to expand the abundant photoresponse mode of photoactive functional crystals. In this study, a 2:1 cocrystal of (E)-4-((4-(propyloxy)phenyl)diazenyl)pyridine (APO3C) and ...tetrafluoroterephthalic acid (TFTA) was designed and synthesized to adjust the robustness of APO3C and to realize new photomechanical motion. The thermal stability of APO3C was enhanced by inserting the coformer. More importantly, photoinduced rotation was achieved under the irradiation of UV light, which was unreported before. A molecular and structural analysis of crystals revealed that the photoinduced rotation can be attributed to three indispensable factors: the linear synthon induced by hydrogen bonding, unsymmetrical isomerization of the APO3C molecules, and their diagonal arrangement. The opposite photoisomerization of APO3C molecules at both ends of a synthon could create torque inside with its diagonal arrangement in three dimensions, producing the unevenness and finally driving the crystal to rotate. The results presented in this work help to enrich the strategy for designing new crystals with novel photoactive functions and expand the diversity of photomechanical molecular crystals through crystal engineering.
•The sonocrystallization and de-agglomeration of ceftezole sodium were investigated.•Agglomeration was efficiently inhibited with ultrasound introduction.•Kapur function was used to investigate the ...de-agglomeration under ultrasound.•Ultrasound mediated de-agglomeration mechanism was determined.
Ultrasound-mediated method, which can effectively disperse agglomerates or even eliminate agglomeration, has received more and more attentions in industrial crystallization. However, the ultrasound-mediated de-agglomeration mechanism has not been well understood, and no general conclusions have been drawn. In this study, the crystallization and de-agglomeration process of ceftezole sodium agglomerates under ultrasound irradiation were systematically investigated. Kapur function was selected to investigate the de-agglomeration process under different ultrasonic powers. The results revealed that ultrasound could efficiently inhibit agglomeration. Besides, the de-agglomeration of large sized agglomerate particles was found to be easier to occur in comparison with small sized particles due to its higher specific breakage rate. Finally, the de-agglomeration mechanism under ultrasonic irradiation was proposed on the basis of the calculated cumulative breakage functions.
With the rapid development of nanotechnology, the convergence of nanostructures and drug delivery has become a research hotspot in recent years. Due to their unique and superior properties, various ...nanostructures, especially those fabricated from self-assembly, are able to significantly increase the solubility of poorly soluble drugs, reduce cytotoxicity toward normal tissues, and improve therapeutic efficacy. Nanostructures have been successfully applied in the delivery of diverse drugs, such as small molecules, peptides, proteins, and nucleic acids. In this paper, the driving forces for the self-assembly of nanostructures are introduced. The strategies of drug delivery by nanostructures are briefly discussed. Furthermore, the emphasis is put on a variety of nanostructures fabricated from various building materials, mainly liposomes, polymers, ceramics, metal, peptides, nucleic acids, and even drugs themselves.
The spontaneous nucleation of d-mannitol polymorphs at different initial concentrations in an aqueous solution was investigated. Two in situ process analytical technology (PAT) tools, Raman ...spectroscopy and focused beam reflectance measurement (FBRM), were combined to monitor the process, allowing instantaneous detection of polymorphs after nucleation. It was found that the stable β form of mannitol was favored at low initial concentrations, whereas the metastable α form nucleated at high concentrations and the metastable δ polymorph crystallized when the concentration was in the medium level. To help understand this phenomenon, the thermodynamic and kinetic characteristics of different polymorphs were analyzed. The solubility of the two metastable forms was determined by an innovative method with the aid of Raman spectroscopy, whereas the interfacial energy between polymorphs and the bulk solution were obtained from the induction time measurements. Consequently, the critical excess free energy and other critical parameters associated with the nucleation of various polymorphs were calculated. It was concluded that the nucleation of mannitol polymorphs from an aqueous solution depends on both the thermodynamic and kinetic properties, with the importance of each highly dependent on the supersaturation prevailing in the system.
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