scholarly journals Design of pH Responsive Textile as a Sensor Material for Acid Rain

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2251
Author(s):  
Viktor Stojkoski ◽  
Mateja Kert
Keyword(s):  
Acid Rain ◽  
Ph Value ◽  
Dye Degradation ◽  
Colour Change ◽  
Polyamide 6 ◽  
Ph Sensitive ◽  
Bromocresol Green ◽  
Colour Fastness ◽  
Sensor Material ◽  
Limit Value

The chemical composition of rainwater can serve as an indicator of the excess of acidifying air pollutants. The pH value of rainwater in the presence of sulphur dioxide and nitrogen oxides, the precursors of acid rain, falls below pH 5.6, which is the limit value for acid rain. In this research, the tailoring of halochromic textile was examined for the design of a functional textile that can serve as a sensor and inform the wearer about the presence of pollutants in the air by means of an immediate colour change. For this purpose, a polyamide 6 fabric was dyed with the pH-sensitive Bromocresol green dye, which causes a colour change below pH 3.6 (yellow) and above pH 5.4 (blue). In addition, the dyed polyamide 6 fabric was treated with a water and oil repellent finish. Colour and colour change before and after immersion of unfinished and finished dyed samples in buffer solutions with different pH values were evaluated spectrophotometrically using the CIELAB colour space. The colour fastness to rubbing, washing, and light, and the water and oil repellency of the dyed fabrics were determined according to valid SIST EN ISO standards. The results showed that the unfinished dyed polyamide 6 fabric undergoes a reversible colour change faster and more clearly than the finished dyed polyamide 6 fabric. The dyed polyamide 6 fabric had good colour fastness to rubbing and domestic and commercial laundering, while the colour fastness to light was poor. In addition, the dyed polyamide 6 fabric was pH-sensitive, despite dye degradation under xenon light, regardless of whether it was finished.

pH-sensitive, dynamic graft polymer micelles via simple synthesis for enhanced chemotherapeutic efficacy

2019 ◽  
Vol 34 (8) ◽  
pp. 1059-1070
Author(s):  
Dapeng Li ◽  
Jiejie Qin ◽  
Min Sun ◽  
Guoqing Yan ◽  
Rupei Tang
Keyword(s):  
Intracellular Ph ◽  
Ph Value ◽  
Ph Sensitive ◽  
Drug Accumulation ◽  
Simple Synthesis ◽  
Hydroxyl Groups ◽  
Graft Polymer ◽  
Polymer Micelles ◽  
Chemotherapeutic Efficacy

To promote chemotherapeutic efficacy and easier clinical transformation, a series of pH-sensitive and dynamic drug delivery systems with facile two-step synthesis and simple structure have been successfully constructed by the tunable grafting reaction between pH-sensitive ortho ester and poly(vinyl alcohol). The amphipathic graft macromolecules (PVA- g-OE x, x represents the percentage of feed between ortho esters and hydroxyl groups of polyvinyl alcohol) could self-assemble into micelles and doxorubicin was embedded. These micelles exhibited pH-sensitivity to both extracellular and intracellular pH and demonstrated the following characteristics: (i) maintaining long-term storage and blood circulation stability at pH 7.4; (ii) responding to tumoral extracellular pH value following gradually larger nanoparticles for improved drug accumulation and retention; (iii) being sensitive to tumoral intracellular pH value following disintegration for rapid drug release to improve toxicity to tumor cells. Moreover, the doxorubicin-loaded micelle (PVA- g-OE30-DOX) showed similar cytotoxicity to free doxorubicin in vitro, but stronger tumor penetration and inhibition ability in vitro human liver carcinoma cell line multicellular tumor spheroids. In vivo biodistribution and tumor inhibition examinations demonstrated that PVA- g-OE30-DOX had more superior efficacy in significantly enhancing drug accumulation in tumor, restraining tumor growth while decreasing drug concentration in normal tissues. The pH-sensitive, dynamic graft polymer micelles via simple synthesis could be considered as a promising and effective drug carrier in tumor therapy.

scholarly journals The precipitation chemistry and acidity over China during 2018

2019 ◽  
Vol 136 ◽  
pp. 06020 ◽  
Author(s):  
Xiaofang Jia ◽  
Jie Tang ◽  
Yong Zhang
Keyword(s):  
Acid Rain ◽  
Ph Value ◽  
Southern China ◽  
Eastern China ◽  
Precipitation Chemistry ◽  
Hunan Province ◽  
Observation Data ◽  
Rain Area ◽  
Chemistry Data ◽  
Precipitation Ph

This paper reports the acid rain observation data from 376 Acid Rain Monitoring stations and the precipitation chemistry data from 5 Global Atmosphere Watch stations of China Meteorological Administration(CMA) during 2018. The variation characteristics of acid rain in China and that of precipitation chemistry in Eastern China are discussed. The results show that the acid rain area in China is mainly distributed in the Southeast and South of China and dispersively in North and Southwest of China. Heavy acid rain area is only limited in Eastern part of Hunan province. The annual mean precipitation pH value of all stations in 2018 ranges from 3.73 to 8.07 and the national annual mean precipitation pH value is 5.94, which is higher than those of 2010-2017. The national annual mean precipitation conductivity is 47.7 μS·cm-1 with the higher conductivity in Northern China and lower in Southern China. Compared with 2010-2017, the acid rain pollution situation over China has been improving nationwide. The precipitation chemistry data shows that the concentration of sulfate is close to nitrate in precipitation and keeps decreasing in recent years.

Degradation of Reactive Red K-2G by a Photoassisted Fenton Reaction Using a Novel Loading Phthalocyanine Sulfonic Iron Fibers as a Catalyst

2011 ◽  
Vol 175-176 ◽  
pp. 712-716
Author(s):  
Hai Ning Lv ◽  
Li Ping Xu ◽  
Cheng Qian
Keyword(s):  
Fenton Reaction ◽  
Ph Value ◽  
Dye Degradation ◽  
Reactive Dyes ◽  
Cellulose Fibers ◽  
Catalyst Loading ◽  
Solution Ph ◽  
Catalyst Dosage ◽  
Silk Fabrics ◽  
Modified Cellulose

Reactive dyes have been widely used in the dyeing of bright colourful silk fabrics. The discoloration and degradation of Reactive Red K-2G in waste water were discussed in this paper. A new heterogeneous photocatalyst named loading phthalocyanine sulfonic iron fibers (FePcS-F) was prepared by phthalocyanine sulfonic Iron supported by modified cellulose fibers in acidic condition. The photocatalytic degradation of Reactive Red K-2G was characterized by discoloration rate to evaluate the effect of catalyst dosage, catalyst loading (CFePcS-F) and solution pH. The results proved that increasing catalyst dosage and CFePcS-F significantly accelerated the dye degradation. FePcS-F catalyst showed higher photocatalytic activity when the solution’s pH value is equal to or less than 6.0, compared to alkaline medium.

Evaluation of heterogeneous photo-Fenton oxidation of Orange II using response surface methodology

2010 ◽  
Vol 62 (6) ◽  
pp. 1320-1326 ◽  
Author(s):  
Y. H. Gong ◽  
H. Zhang ◽  
Y. L. Li ◽  
L. J. Xiang ◽  
S. Royer ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Heterogeneous Catalyst ◽  
Uv Irradiation ◽  
Heterogeneous Catalysts ◽  
Ph Value ◽  
Dye Degradation ◽  
High Catalytic Activity ◽  
Orange Ii ◽  
Initial Ph

A mesoporous SBA-15 doped iron oxide (Fe2O3/SBA-15) was synthesized by co-codensation, characterized and used as heterogeneous catalysts for the photo-Fenton decolorization of azo dye Orange II under UV irradiation. Response surface methodology (RSM) was used to investigate operating condition effects, such as hydrogen peroxide concentration, initial pH and catalyst loadings, on the decolorization rate. UV irradiation is found to enhance the activity of the catalyst in the process. RSM analysis evidenced the influence of the initial pH value and H2O2 concentration on the dye degradation rate. The coupled UV/Fe2O3/SBA-15/H2O2 process at room temperature is revealed as a promising friendly process for wastewater treatment. Indeed, the use of a heterogeneous catalyst allows an easy active phase recycling without multi-step recovering while the heterogeneous catalyst used here exhibits high catalytic activity for the reaction considered.

Enhanced Photocatalytic Performance and Mechanism of Ag3PO4 Particles Synthesized via a Sonochemical Process

2018 ◽  
Vol 10 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Chengxiang Zheng ◽  
Hua Yang ◽  
Yang Yang ◽  
Haimin Zhang
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Ph Value ◽  
Dye Degradation ◽  
Sonochemical Method ◽  
Simulated Sunlight ◽  
Spherical Nanoparticles ◽  
Direct Oxidation

A facile sonochemical method was used to synthesize Ag3PO4 particles and the effect of pH value, reaction temperature and reaction time on the products was investigated. It is found that the samples prepared at neutral (pH = 7) and alkaline (pH = 11) environments exhibit a similar particle morphology and size. The particles are shaped like spheres with a size distribution majorly focusing on a range of 200–450 nm, and the average particle size is about 300 nm. The sample prepared at acidic environment (pH = 3) is composed of polyhedral microparticles with size of 5–8 μm. At relatively low temperatures of 20–50 °C, the spherical nanoparticles do not undergo obvious morphology/size changes; however, when the temperature is increased up to 80 °C, the nanoparticles are aggregated to form large-sized polyhedral microparticles in the size range of 4–7 μm. Compared to the pH value and reaction temperature, the reaction time has a minor effect on the morphology of Ag3PO4 particles. RhB was chosen as the target pollutant to evaluate the photocatalytic activity of the as-prepared Ag3PO4 samples under simulated-sunlight irradiation. It is shown that the samples consisting of spherical nanoparticles exhibit an extremely high photocatalytic activity, and the degradation percentage of RhB after reaction for 50 min reaches over 90%. The samples of polyhedral microparticles have a relatively low photocatalytic activity, which is possibly due to their large particle size. Hydroxyl (.OH) radical was detected by spectrofluorimetry using terephthalic acid as a .OH scavenger and was not found to be produced over the simulated-sunlight-irradiated Ag3PO4 catalyst. The effect of ethanol, benzoquinone and ammonium oxalate on dye degradation was also investigated. Based on experimental results, the direct oxidation by h+ is suggested to the dominant mechanism toward the dye degradation.

pH-Sensitive gold nanoclusters: preparation and analytical applications for urea, urease, and urease inhibitor detection

2015 ◽  
Vol 51 (37) ◽  
pp. 7847-7850 ◽  
Author(s):  
Hao-Hua Deng ◽  
Gang-Wei Wu ◽  
Zhi-Qiang Zou ◽  
Hua-Ping Peng ◽  
Ai-Lin Liu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ph Value ◽  
Gold Nanoclusters ◽  
Ph Sensitive ◽  
Urease Inhibitor ◽  
Analytical Applications ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

The urease-catalyzed hydrolysis of urea releases ammonia and carbon dioxide as products. The pH value increases as the urea degradation occurs, as a result, quenching the fluorescence of NAC-AuNCs.

Sign in / Sign up

Export Citation Format

Share Document