Rapid Removal of Methylene Blue in Water Using Polymer-Based Biochar Nanocomposite-Coated Filters

2021 ◽  
Vol 324 ◽  
pp. 116-124
Author(s):  
Edgar Clyde R. Lopez ◽  
Nathaniel M. Saporsantos ◽  
William Ven R. Magbalon ◽  
Richard C. Aquino ◽  
Miguel Lawrence Keith S.J. Celebre ◽  
...  

In this study, the effectiveness of novel nanocomposite-coated filters consisting of biochar (BC) functionalized with sodium alginate (SA) and poly (vinyl alcohol) (PVA) was investigated for methylene (MB) blue removal. The filters were fabricated via a dip-coating method and SEM and FTIR spectroscopy confirmed the successful coating of the filters. The impact of the nanocomposite formulation and the operating parameters (initial pH and MB concentration) on the performance of the coated filters were studied. A nanocomposite composition consisting of 1.0 wt.% SA, 2.0 wt.% PVA, and 1000 ppm BC were found to be optimum, reaching as high as 96.51% MB removal. The fabricated filters were determined to be robust over a wide range of pH and initial MB concentrations. The Sips isotherm model proved to be the best-fit model for MB adsorption, where chemisorption dominates at low MB concentrations, while physisorption dominates at high MB concentrations. The filters have a maximum sorption capacity of 54.5198 mg g-1 and showed good reusability. Overall, our synthesized SA/PVA/BC-coated filters can be used to effectively remove dyes in wastewater over a wide range of operating conditions.

Author(s):  
Hiroyuki Kosukegawa ◽  
Chihaya Kiyomitsu ◽  
Makoto Ohta

To control the thickness of a PVA-H biomodel of human arteries and veins (150 to 800 μm in thickness), a three-dimensional-rotating spin dip-coating apparatus was fabricated. A straight aluminum cylinder (Ra = 0.16 μm) was employed as substrate. Spin dip-coating was carried out in a cooling chamber at 10°C for 1 hour, and then the substrate was quenched at −30°C for gelation of PVA. The thickness of the deposited PVA-H was measured by using a confocal laser displacement meter. Under the experimental conditions employed, PVA-H with a thickness over 30 μm was obtained. The thickness linearly increased with repeated dippings. The thickness of PVA-H depends on the dipping withdrawal speed, the viscosity of the PVA solution, and the diameter of the substrate. Furthermore, the thickness of PVA-H was found to be almost the same when the viscosity of the PVA solution was constant, regardless of the concentrations of PVA. These results indicate that a tube-shaped PVA-H biomodel with desired thickness and physical properties can be obtained by using a spin dip-coating technique and that PVA-H can mimic the wall thickness of various arteries and veins.


2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.


2018 ◽  
Vol 5 (2) ◽  
pp. 16-18
Author(s):  
Chandar Shekar B ◽  
Ranjit Kumar R ◽  
Dinesh K.P.B ◽  
Sulana Sundar C ◽  
Sunnitha S ◽  
...  

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.


2021 ◽  
Vol 1115 (1) ◽  
pp. 012028
Author(s):  
P T P Aryanti ◽  
G Trilaksono ◽  
A Hotmaida ◽  
M A Afifah ◽  
F P Pratiwi ◽  
...  

Author(s):  
Gözde Çelebi Efe ◽  
Elif Yenilmez ◽  
İbrahim Altinsoy ◽  
Serbülent Türk ◽  
Cuma Bindal

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
M. Selin Sunay ◽  
Onder Pekcan ◽  
Saziye Ugur

Steady-state fluorescence (SSF) technique in conjunction with UV-visible (UVV) technique and atomic force microscope (AFM) was used for studying film formation from TiO2covered nanosized polystyrene (PS) latex particles (320 nm). The effects of film thickness and TiO2content on the film formation and structure properties of PS/TiO2composites were studied. For this purpose, two different sets of PS films with thicknesses of 5 and 20 μm were prepared from pyrene-(P-) labeled PS particles and covered with various layers of TiO2using dip-coating method. These films were then annealed at elevated temperatures above glass transition temperature () of PS in the range of 100–280°C. Fluorescence emission intensity, from P and transmitted light intensity, were measured after each annealing step to monitor the stages of film formation. The results showed that film formation from PS latexes occurs on the top surface of PS/TiO2composites and thus developed independent of TiO2content for both film sets. But the surface morphology of the films was found to vary with both TiO2content and film thickness. After removal of PS, thin films provide a quite ordered porous structure while thick films showed nonporous structure.


2019 ◽  
Vol 32 (6) ◽  
pp. 611-619 ◽  
Author(s):  
Xiaoli Liu ◽  
Zhen Ge ◽  
Wenguo Zhang ◽  
Yunjun Luo

Due to their unique physicochemical properties, polysilazanes exhibit excellent performance when combined with some resin matrixes, which had drawn great research attention. In this article, polyurethane (PU) was firstly prepared by polytetrahydrofuran glycol, isophorone diisocyanate, and 1,4-butanediol as main materials. Then, the prepared PU was blended with polysilazane by mixing the two solutions together, which was cured to films via dip-coating method at room temperature. The structure, thermal stability, and surface properties of the composite coatings were investigated by Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. The results demonstrated that after modification with polysilazane, the heat resistance, hydrophobicity, and mechanical property of the PU coatings were improved. When the content of polysilazane was 6 wt%, the mechanical property of the composite films was optimized, with a maximum tensile strength of 25.7 MPa and elongation at break of 797%. Meanwhile, the water contact angle of the composite film was 107° and the water absorption reached a minimum of 2.1%, which showed improved hydrophobicity and water resistance.


Langmuir ◽  
2014 ◽  
Vol 30 (30) ◽  
pp. 9028-9035 ◽  
Author(s):  
J. Dugay ◽  
R. P. Tan ◽  
A. Loubat ◽  
L.-M. Lacroix ◽  
J. Carrey ◽  
...  

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