Graphene films were successfully synthesized by atmospheric pressure chemical vapor deposition (APCVD) method. Methane (CH4) gas and copper (Cu) tapes were used as a carbon source and a catalyst, respectively. The CVD temperature and time were in the range of 800–1000 °C and 10 s to 45 min, respectively. The role of the CVD temperature and time on the growth of graphene films was investigated in detail via scanning electron microscopy (SEM) and Raman spectroscopy techniques. The results of SEM images and Raman spectra show that the quality of the graphene films was improved with increasing of CVD temperature due to the increase of catalytic activity.

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Although forward osmosis (FO) membranes have shown great promise for many applications, there are few studies attempting to create a systematization of the testing conditions at a pilot scale for FO membrane modules. To address this issue, hollow fiber forward osmosis (HFFO) membrane modules with different performances (water flux and solute rejection) have been investigated at different operating conditions. Various draw and feed flow rates, draw solute types and concentrations, transmembrane pressures, temperatures, and operation modes have been studied using two model feed solutions—deionized water and artificial seawater. The significance of the operational conditions in the FO process was attributed to a dominant role of concentration polarization (CP) effects, where the selected draw solute and draw concentration had the biggest impact on membrane performance due to internal CP. Additionally, the rejection of the HFFO membranes using three model solutes (caffeine, niacin, and urea) were determined under both FO and reverse osmosis (RO) conditions with the same process recovery. FO rejections had an increase of 2% for caffeine, 19% for niacin, and 740% for urea compared to the RO rejections. Overall, this is the first extensive study of commercially available inside-out HFFO membrane modules.

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Herein, we introduce a reusable Brønsted acidic ionic liquid gel (BAIL gel) obtained by treating 1-methyl-3-(4-sulfobutyl)-1 H -imidazolium hydrogen sulfate with tetraethyl orthosilicate (TEOS). The grafting of the Brønsted acidic ionic liquid to the surface of TEOS has increased the catalytic activity of the material and also simplified catalyst recovery from the reaction mixture. This reaction has a wide substrate scope, and the BAIL gel represents a new catalyst for the synthesis of benzoxazoles, benzimidazoles, and benzothiazoles. The method shows attractive characteristics such as high yields, recyclable catalyst, and work-up simplicity. More importantly, no additional additives or volatile organic solvent and inert atmosphere are required for the reaction, and the BAIL gel has shown a great promise for industrial applications. To the best of our knowledge, the synthesis of benzoxazoles, benzimidazoles, and benzothiazoles using a recyclable heterogeneous ionic liquid gel was not previously reported in the literature.

The preparation and characterization of graphene films for cholesterol determination are described. The graphene films were synthesized by thermal chemical vapor deposition (CVD) method. Methane gas (CH4) and copper tape were used as carbon source and catalyst in the graphene growth process, respectively. The intergrated array was fabricated by using micro-electro-mechanical systems (MEMS) technology in which Fe3O4-doped polyaniline (PANi) film was electropolymerized on Pt/Gr electrodes. The properties of the Pt/Gr/PANi/Fe3O4 films were investigated by field-emission scanning electron microscopy (FE-SEM), Raman spectroscopy and electrochemical techniques. Cholesterol oxidase (ChOx) has been immobilized onto the working electrode with glutaraldehyde agent. The cholesterol electrochemical biosensor shows high sensitivity (74 μA mM−1 cm−2) and fast response time (<5 s). A linear calibration plot was obtained in the wide cholesterol concentration range from 2 to 20 mM and correlation coefficient square (R2) of 0.9986. This new layer-by-layer biosensor based on graphene films promises many practical applications.

This paper describes a glucose electrochemical biosensor, layer-by-layer fabricated from graphene and polyaniline films. Graphene sheets (0.5×0.5 cm 2) with the thickness of 5 nm (15 layers) were synthesized by thermal chemical vapor deposition (CVD) under ambient pressure on copper tapes. Then they were transferred into integrated Fe 3 O 4-doped polyaniline (PANi) based microelectrodes. The properties of the nanocomposite films were thoroughly characterized by scanning electron microscopy (SEM), Raman spectroscopy, atomic force microscopy (AFM) and electrochemical methods, such as square wave voltametry (SWV) and chronoamperometry. The above graphene patterned sensor (denoted as Graphene/Fe 3 O 4/PANi/GOx) shows much improved glucose sensitivity (as high as 47 μA  mM −1  cm −2) compared to a non-graphene one (10–30 μA  mM −1  cm −2, as previously reported in the literature). It can be expected that this proof-of-concept biosensor could be extended for other highly sensitive biodetection.

AB rønsted-acidic ionic liquid gel was prepared from 1-(4-sulfonic acid)butyl-3-methylimidazolium hydrogen sulfate and tetraethoxysilane. Its structural characterization was accomplished by FTIR, TGA, SEM, EDS, and ICP-OES. The ionic liquid gel promotes the synthesis of bis(indolyl)methanes. Interestingly,t his catalyst allowst he preparation of bis(indolyl)methanes in good to excellenty ields within a short reaction time, through ac lean and straightforward procedure. Moreover,t he ionic liquid gel can be recovered by filtration and can be reused up to 5t imes without any detectable loss of catalytic performance. Additionally,t he methodh as aw ide substrate scope and provides an accessible route for the large-scale direct synthesis of bis(indolyl)-methanes.