scholarly journals PES-Ag3PO4/g-C3N4 Mixed Matrix Film Photocatalyst for Degradation of Methyl Orange Dye

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1746
Author(s):  
Hayati Mohamad Mukhair ◽  
Abdul Halim Abdullah ◽  
Zulkarnain Zainal ◽  
Hong Ngee Lim

In the present study, we explored the effectiveness of PES-Ag3PO4/g-C3N4 film photocatalyst in degrading methyl orange dye under visible light irradiation. The PES-Ag3PO4/g-C3N4 film photocatalyst was prepared via a non-solvent-induced phase inversion process and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), laser scanning microscopy (LSM), X-ray photoelectron spectra (XPS), UV-diffuse reflectance (DRS), and water contact angle. The incorporation of the Ag3PO4/g-C3N4 composite into the PES matrix improved the pristine PES film’s hydrophilicity, as evidenced by the reduction of water contact angle from 79.03° to 54.33° for a film containing 15 wt % of Ag3PO4/g-C3N4 composite. The film’s photoactivity showed that 13 wt % was the best loading of Ag3PO4/g-C3N4 composite, and the degradation performance was maintained up to three cycles. The •O2− and h+ were the predominant species responsible for the methyl orange degradation.

2020 ◽  
Author(s):  
Xiaodie Wang ◽  
Limin Liu ◽  
Xiaoyan Zhou ◽  
Yongbiao Huo ◽  
Jinlong Gao ◽  
...  

Abstract Background Recent preventive strategies for dental caries focus on targeting the mechanisms underlying biofilm formation, including inhibiting bacterial adhesion. A promising approach to prevent bacterial adhesion is to modify the composition of acquired salivary pellicle. This in vitro study investigated the effect and possible underlying mechanism of pellicle modification by casein phosphopeptide (CPP) on Streptococcus mutans (S. mutans) initial adhesion, and the impact of fluoride on the efficacy of CPP.Methods The salivary pellicle-coated hydroxyapatite (s-HA) disc was modified by 2.5% CPP or 2.5% CPP supplemented with 900 ppm fluoride solutions. After cultivation of S. mutans, the adherent bacteria were visualized by scanning electron microscopy (SEM) and quantitatively evaluated using the plate count method. Confocal laser scanning microscopy (CLSM) was used to evaluate the proportions of total and dead S. mutans. The concentrations of total, free, and bound calcium and fluoride in CPP and fluoride-doped CPP solutions were determined. The water contact angle and zeta potential of s-HA with and without modification were measured. The data were statistically analyzed using one-way ANOVA followed by a Turkey post hoc multiple comparison test.Results Initial adhesion of S. mutans to s-HA was inhibited in response to pellicle modification by CPP and fluoride-doped CPP, and the latter was more efficient. CLSM analysis showed that the proportion of dead S. mutans did not differ between the groups. Water contact angle and zeta potential decreased after pellicle modification, and both were lowest in the fluoride-doped CPP group.Conclusions Pellicle modification by CPP inhibited S. mutans initial adhesion to s-HA, possibly by reducing hydrophobicity and negative charge on the s-HA surface, and incorporating fluoride into CPP enhanced its anti-adhesion effect.


2021 ◽  
Vol 29 (9_suppl) ◽  
pp. S1361-S1370
Author(s):  
Xuwu Luo ◽  
Guancheng Jiang ◽  
Xinliang Li ◽  
Lili Yang

In this paper, sodium montmorillonite was modified with gelatin of different concentrations, and various colloidal characteristics of the gelatin-treated clays were measured and analyzed in detail. First, the influence of gelatin on the interlayer space of Mt layers was investigated by X-ray diffraction analysis. Moreover, the aggregation of Mt particles was examined using a combination of electron microscopy and particle size distribution experiments, while the variation of the electrical property of Mt was measured using ζ potential test. Gelatin of different concentrations can increase the particle size of Mt in different degrees. The addition of 4% gelatin could improve the ζ potential of Mt from −30.65 to −15.55 mV. The wettability change of modified Mt induced by the adsorption of gelatin was followed by measurements of water contact angle and observations of the morphology of Mt/gelatin membrane through SEM images. 4% gelatin could improve the water contact angle of Mt to 81.3°. Finally, the rheological properties of Mt/gelatin dispersion including shear viscosity and shear stress were measured using a stress-controlled rheometer. All of the results were consistent by showing that the overall colloidal characteristics and behavior of the gelatin-treated Mt strongly varied depending on the gelatin concentration used in the modification process. These results can provide a deep and comprehensive understanding of the colloidal properties of clay/gelatin systems and give important guidance for the performance design and improvement of Mt/gelatin composite materials. Furthermore, this study can also be expanded the application of gelatin and its composites to other fields.


2020 ◽  
Author(s):  
Xiaodie Wang ◽  
Limin Liu ◽  
Xiaoyan Zhou ◽  
Yongbiao Huo ◽  
Jinlong Gao ◽  
...  

Abstract Background: Recent preventive strategies for dental caries focus on targeting the mechanisms underlying biofilm formation, including inhibiting bacterial adhesion. A promising approach to prevent bacterial adhesion is to modify the composition of acquired salivary pellicle. This in vitro study investigated the effect and possible underlying mechanism of pellicle modification by casein phosphopeptide (CPP) on Streptococcus mutans (S. mutans) initial adhesion, and the impact of fluoride on the efficacy of CPP. Methods: The salivary pellicle-coated hydroxyapatite (s-HA) discs were treated with phosphate buffered saline (blank control), heat-inactivated 2.5% CPP (negative control), 2.5% CPP (CPP) or 2.5% CPP supplemented with 900 ppm fluoride (CPP + F). After cultivation of S. mutans, the adherent bacteria were visualized by scanning electron microscopy (SEM) and quantitatively evaluated using the plate count method. Confocal laser scanning microscopy (CLSM) was used to evaluate the proportions of total and dead S. mutans. The concentrations of total, free, and bound calcium and fluoride in CPP and fluoride-doped CPP solutions were determined. The water contact angle and zeta potential of s-HA with and without modification were measured. The data were statistically analyzed using one-way ANOVA followed by a Turkey post hoc multiple comparison test.Results: Initial adhesion of S. mutans to s-HA was inhibited in response to pellicle modification by CPP and fluoride-doped CPP, and the latter was more efficient. CLSM analysis showed that the proportion of dead S. mutans did not differ between the groups. Water contact angle and zeta potential decreased after pellicle modification, and both were lowest in the CPP + F group. Conclusions: Pellicle modification by CPP inhibited S. mutans initial adhesion to s-HA, possibly by reducing hydrophobicity and negative charge on the s-HA surface, and incorporating fluoride into CPP enhanced its anti-adhesion effect.


2008 ◽  
Vol 55-57 ◽  
pp. 925-928 ◽  
Author(s):  
C. Salawan ◽  
A. Muakngam ◽  
B. Sukbot ◽  
K. Aiempanakit ◽  
Supattanapong Dumrongrattana

In this work, we present the effect of DC power from 100 W to 500 W on the structural and hydrophilic activity of TiO2 films. The TiO2 films were prepared by DC magnetron sputtering on the glass substrate without any external heating. The structure of TiO2 films were analyzed by atomic force microscope and X-ray diffraction. XRD patterns indicated the films were amorphous. The surface roughness and grain size were enlarged by the increasing of the DC power while the substrate temperature was climbed up with the increasing of the DC power. From the point of energetic ion bombardment, it was related with DC power between sputtering processes. The hydrophilic activity of TiO2 films were analyzed by the contact angle meter. The water contact angle decrease with increasing of the DC power.


2012 ◽  
Vol 487 ◽  
pp. 730-734 ◽  
Author(s):  
Chang Jiang Pan ◽  
Yu Dong Nie ◽  
Yun Xiao Dong

In this paper, two kinds of stamps (squares (a×a)) separated by spacing b, the values of a and b were varied from 2.5 µm to 50 µm), i.e. positive and negative stamps, were prepared. The stamps inked with the rhodamine-labeled bovine serum albumin (BSA) were then microcontacted with the aldehyde-functionalized titanium surfaces. Water contact angle and X-ray photoelectron spectrum (XPS) indicated that BSA can be covalently immobilized on aldehyde modified titanium surface by microcontact printing. The experimental results of CLSM showed that the patterns with resolution from 2.5 µm to 50 µm were obtained successfully. Both positive stamp and negative stamp were deformed when the value of a was less than or equal to 5 µm, which resulted in replication errors. Furthermore, the larger spacing (50 µm) resulted in stamp collapse when the value a of the positive stamp was less than or equal to 10 µm, leading to whole fluorescence on substrates.


2011 ◽  
Vol 364 ◽  
pp. 377-381 ◽  
Author(s):  
Syazwani Mohd Zaki ◽  
Srimala Sreekantan

This paper described the preparation of Cu loaded TiO₂ nanotube arrays. Firstly, TiO₂ nanotube arrays were formed by anodization. Afterwards, the formed nanotube arrays were incorporated with Cu by wet impregnation method. The soaking time and concentration were varied to obtain an optimum set of parameter for Cu incorporation in TiO₂ nanotubes. After anodization, all samples were annealed at 400°C for 4 hours to obtain anatase phase. The nanotube arrays were characterized by field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD) and x-ray photoelectron spectra (XPS). An average diameter 63.02 nm and length 12.15µm were obtained for TiO₂ nanotubes. The photocatalytic activity of these nanotubes were investigated with methyl orange (MO) and the TiO₂ nanotube prepared in 0.01M of Cu (NO₃)₂ solution within 3 hours demonstrates the highest photocatalytic activity with 83.6% degradation of methyl orange. Keywords: copper doping, wet impregnation, photocatalytic activity


2006 ◽  
Vol 15-17 ◽  
pp. 187-192 ◽  
Author(s):  
Ko Shao Chen ◽  
Su Chen Chen ◽  
Yi Chun Yeh ◽  
Wei Cheng Lien ◽  
Hong Ru Lin ◽  
...  

Expanded polytetrafluoroethylene (ePTFE) is a bioinert material. To improve the ePTFE film biocompatibility, the cold plasma technology was used with acetic acid as monomer to deposit onto ePTFE film and then (N-isopropylacrylamide) was grafted onto the surface by photo-grafting. The characteristics of the surface were evaluated with X-ray photoelectron spectroscopy (XPS), FTIR and water contact angle. It was found that the contact angle of water on the untreated ePTFE significantly decrease from125° to 72° after ePTFE film being treated with acetic acid plasma deposition treatment. Due to the hydrophilicity of poly(N-isopropylacrylamide), the contact angle of water on the ePTFE-g-NIPAAm approached to 0°.


2011 ◽  
Vol 306-307 ◽  
pp. 1631-1634 ◽  
Author(s):  
Ya Kai Feng ◽  
Da Zhi Yang ◽  
Hai Yang Zhao ◽  
Jin Tang Guo ◽  
Qing Liang Chen ◽  
...  

Poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate) (poly(DMAPS)) zwitterionic brushes were grafted onto the polycarbonateurethane (PCU) surface to improve its hydrophilicity and hemocompatibility by Ultraviolet (UV) polymerization. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surface. DMAPS-grafted PCU films showed significantly high hydrophilicity owing to the high hydrophilic poly(DMAPS) zwitterionic brushes. The cytotoxicity tests revealed the sulfoammonium zwitterionic brushes modified PCU film had good cytocompatibility. In addition, the hemocompatibility of the modified PCU films was evaluated by hemolytic tests and platelet adhesion tests. The PCU films modified with zwitterionic brushes had a lower hemolytic index, showed effective resistance to platelet adhesion. Due to the fact that sulfoammonium zwitterionic brushes can improve the hemocompatibility of the PCU surface, this gives rise to its potential application as blood-contacting materials or devices.


2011 ◽  
Vol 306-307 ◽  
pp. 3-6
Author(s):  
Hai Yang Zhao ◽  
Ya Kai Feng ◽  
Da Zhi Yang ◽  
Jin Tang Guo ◽  
Qing Liang Chen ◽  
...  

In order to improve the hemocompatibility of polycarbonateurethane (PCU), the biomimetic phosphorylcholine (PC) group was introduced onto material surface. Brush structure having PC groups was formed by ultraviolet (UV) initiated polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve the hydrophilicity and hemocompatibility of PCU surfaces. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electrical microscopy (SEM) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surfaces. Compared with original PCU, the PC-grafted PCU surfaces showed significantly high hydrophilicity as indicating by low water contact angle. The hemocompatibility of the PC-grafted PCU surfaces was evaluated by platelet adhesion test. The PCU surfaces modified with phosphorylcholine zwitterionic brushes showed effective resistance to platelet adhesion and high hemocompatibility. These PC-grafted PCU materials will have potential application as blood-contacting materials or devices due to their good mechanical and hemocompatible properties.


2011 ◽  
Vol 412 ◽  
pp. 163-166 ◽  
Author(s):  
Ya Wei Hu ◽  
Hui Rong He ◽  
Yang Min Ma

In this work, we fabricated indium hydroxide (In (OH)3) nanocubes from In (NO3)3 and urea through hydrothermal method. NH4OH form the hydrolysis of urea acts as the OH¯ provider. The resultant products were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), photoluminescence (PL) spectra and contact angle meter. It was observed that the In (OH)3 nanocubes showed superhydrophobicity with water contact angle 161.9° after modified with fluoroalkylsilane (FAS, CF3(CF2)7CH2CH2Si (OCH3)3), and exhibited PL peak at about 529 nm, corresponding to the deep level emission.


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