Performance evaluation and antifouling analyses of cellulose acetate/nanodiamond nanocomposite membranes in water treatment

In this study, nanocomposite membranes based on cellulose acetate (CA) and nanodiamond (ND) were prepared by applying phase inversion methods. In order to achieve efficient dispersion and more hydrophilic NDs, they were functionalized via heat treatment (ND‐COOH). The prepared nanocomposite membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), contact angle, porosity measurement, tensile strength, and abrasion resistance techniques. Furthermore, the governing fouling mechanisms were determined by using classic models as well as combined fouling models. Moreover, the effect of precoagulation with polyaluminum chloride (PAC) on the humic acid (HA) filtration was investigated. The obtained results showed that in the presence of ND‐COOH, the abrasion resistance of nanocomposite CA membrane was three times higher than that of pristine CA membrane. Besides, the nanocomposite membranes with 0.5 wt % of raw and functionalized ND exhibited excellent hydrophilicity and PWF. The analysis of fouling mechanism based on Hermia's model revealed that the cake formation is prevailing mechanism for CA and CA/ND (0.5 wt %) membranes while for CA/ND‐COOH (0.5 wt %) membrane, experimental results are fitted by combined cake filtration‐complete blocking (CFCB) model. It confirms that pretreatment with PAC can significantly mitigate fouling and improve HA removal. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44873.     

Application of tin(IV) porphyrin complexes as novel catalysts for the synthesis of new copolyurethanes with cyclopeptide moiety

New electron deficient tin(IV) porphyrins were used as efficient catalysts for the reaction of 4,4′‐methylene‐bis‐(4‐phenylisocyanate) (MDI), with L‐leucine anhydride cyclodipeptide (LAC) and polyethyleneglycol‐400 (PEG‐400) and the results were compared with those obtained in the presence of a commercial catalyst, dibutyltin dilaurate (DBTDL). Molar ratio of catalysts to MDI, polymerization reaction time, viscosity, and yield of the resulting poly(ether‐urethane‐urea)s (PEUU) were compared in the presence of different catalysts. The rate of N?C?O conversion in the presence of each catalysts under the same reaction conditions was also compared and followed by FT‐IR N?C?O absorption band. FT‐IR, GPC, and viscosity studies have shown that tin(IV) porphyrins afford higher viscosity and reaction progress. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Diastereoselective Synthesis of Pyrazolines using a Bifunctional Brønsted Acidic Ionic Liquid under Solvent‐Free Conditions

An efficient protocol for the excellent diastereoselective synthesis of pyrazolines via a three‐component reaction of aldehydes, hydrazines and dimethyl acetylenedicarboxylate (DMAD) in the presence of a bifunctional Brønsted acidic ionic liquid as a reusable catalyst under solvent‐free conditions is reported. Easy work‐up, short reaction times, high yields of the products and an environmentally benign procedure avoiding toxic organic solvents are other significant features of this method.     

Reactions of Oxiranes and Carbonyl Compounds Catalyzed by Ammonium Decatungstocerate(IV)

Various types of oxiranes react with acetone in the presence of catalytic amounts of ammonium decatungstocerate(IV) icosahydrate, (NH₄)₈[CeW₁₀O³⁶] ? 20H₂O, to give the corresponding 1,3-dioxolanes in excellent yields.     

Synthesis and Characterization of Nano Silica Supported Tungstophosphoric Acid: An Efficient, Reusable Heterogeneous Catalyst for the Synthesis of Azlactones

A rapid and scale up protocol for the synthesis of azlactones by the Erlenmeyer method under solvent-free conditions was developed. Tungstophosphoric acid supported on nano-silica, TPA@nano-SiO₂ was used as a heterogeneous catalyst for the synthesis of a wide range of azlactone derivatives. The catalyst was characterized by physicochemical measurements. The procedure was simple and permitted the quantitative isolation of products and catalyst under thermal conditions. The recycled catalyst was reused more than 5-times without loss of catalytic activity.     

Ammonium decatungstocerate (IV): an efficient catalyst for ring opening of epoxides with aromatic amines

A mild, convenient and efficient ring opening of oxiranes with aromatic amines was catalyzed by ammonium decatungstocerate (IV) in acetonitrile. The reaction afforded the corresponding products in 92–100% yields. The catalyst was reused for several times with consistent activity.     

K5CoW12O40⋅3H2O: A Novel Cobalt Polyoxometalate Catalyst for Conversion of Epoxides to Acetonides

A mild and efficient preparation of 1,3-dioxolanes from epoxides and acetone has been carried out in high to excellent yields under catalysis of potassium dodecatungstocobaltate trihydrate (K₅CoW₁₂O₄₀3H₂O) (0.01 molar equiv.).     

Usability of whey powder as an alternative protein source in ruminant nutrition

Clean Technologies and Environmental Policy - Remaining agricultural and food waste in the environment without use can cause environmental pollution. However, some of these agricultural wastes can...     

An innovative algorithm for tuning of composite nonlinear feedback control in continuous-time systems

The transient response improvement is the most crucial feature of the composite nonlinear feedback (CNF) controllers. This study proposes a novel CNF tuning method for systems subject to saturation. To achieve the goals, the linear part is optimally obtained via a performance index and the linear matrix inequality (LMI). Then, employing the passivity property, a heuristic way is suggested to adjust the nonlinear term. Thus, the automatic and online features would be the key novelties of this algorithm compared with the offline, trial and error, or nonautomatic ones. Some systems are simulated to evaluate the technique and compare with the existing methods. The outcomes confirm that the proposed tuning yields outstanding improvement concerning the aforementioned systems.