Dual Functional Alginate‐Polyethylene Polyamine Composite Aerogel Toward Sensing and Extracting Copper Ions in Water

2021 ◽  
Vol 6 (7) ◽  
pp. 1526-1532
Author(s):  
Zhuqing Wang ◽  
Leilei Yang ◽  
Qi Yang ◽  
Min Wang
2021 ◽  
Author(s):  
Xin Ye ◽  
Sisi Shang ◽  
Yifan Zhao ◽  
Sheng Cui ◽  
Ya Zhong ◽  
...  

Abstract The modified montmorillonite(MMT) has a two-dimensional stable and ordered lamellar structure. The addition of chitosan(CS) cross-links the two-dimensional sheets to build a three-dimensional network structure with a high specific surface area. We have prepared the best MMT-based water treatment materials that have been reported. This new type of aerogel can efficiently adsorb heavy metal ions in wastewater. The structure and performance of the composite material were characterized in this article. Besides, the adsorption kinetics, adsorption thermodynamics, pH influence, and recycling performance are all focused on. The adsorption equilibrium time of CS-MMT2 is 50 min. The removal rate of Cu2+ is as high as 98.21%. The maximum adsorption capacity is 86.95 mg/g. The adsorption process of Cu2+ by CS-MMT composite aerogel conforms to the quasi-second-order kinetic model and the Langrangian adsorption isotherm. After three cycles, the removal rate of Cu2+ by CS-MMT2 remained above 80%. This article also involves the discussion of the material's adsorption mechanism for Cu2+. This is a kind of environmentally friendly material that can be mass-produced, cheap, efficient, and excellent, which is of great significance to the development of environmental protection.


2017 ◽  
Vol 253 ◽  
pp. 437-450 ◽  
Author(s):  
Taha M. Elmorsi ◽  
Tarek S. Aysha ◽  
Oldřich Machalický ◽  
Mahmoud Basseem I. Mohamed ◽  
Ahmed H. Bedair

Cellulose ◽  
2021 ◽  
Author(s):  
Xin Ye ◽  
Sisi Shang ◽  
Yifan Zhao ◽  
Sheng Cui ◽  
Ya Zhong ◽  
...  

1965 ◽  
Vol 13 (02) ◽  
pp. 477-483
Author(s):  
Alwin B. Bogert

SummaryExperiments were conducted to determine why different lots of Borate Buffer reagent affect the clot lysis times obtained in the fibrinolytic assay of Streptokinase. Minerals naturally occurring in distilled water were screened individually to determine their influence on lysis. Copper was found to have a very pronounced effect in this regard on the fibrinolytic system in that low levels reduce the lysis time and high levels increase it.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.


2003 ◽  
Vol 766 ◽  
Author(s):  
Ahila Krishnamoorthy ◽  
N.Y. Huang ◽  
Shu-Yunn Chong

AbstractBlack DiamondTM. (BD) is one of the primary candidates for use in copper-low k integration. Although BD is SiO2 based, it is vastly different from oxide in terms of dielectric strength and reliability. One of the main reliability concerns is the drift of copper ions under electric field to the surrounding dielectric layer and this is evaluated by voltage ramp (V-ramp) and time dependent dielectric breakdown (TDDB). Metal 1 and Metal 2 intralevel comb structures with different metal widths and spaces were chosen for dielectric breakdown studies. Breakdown field of individual test structures were obtained from V-ramp tests in the temperature range of 30 to 150°C. TDDB was performed in the field range 0.5 – 2 MV/cm. From the leakage between combs at the same level (either metal 1 or metal 2) Cu drift through SiC/BD or SiN/BD interface was characterized. It was found that Cu/barrier and barrier/low k interfaces functioned as easy paths for copper drift thereby shorting the lines. Cu/SiC was found to provide a better interface than Cu/SiN.


2019 ◽  
Author(s):  
Enrico Bergamaschi ◽  
Frédéric Beltran ◽  
Christopher Teskey

<p></p><p></p><p>Switchable catalysis offers opportunities to control the rate or selectivity of a reaction <i>via</i> a stimulus such as pH or light. However, few examples of switchable catalytic systems that can facilitate multiple processes exist. Here we report a rare example of such dual-functional, switchable catalysis. Featuring an easily prepared, bench-stable cobalt(I) hydride complex in conjunction with pinacolborane, we can completely alter the reaction outcome between two widely employed transformations – olefin migration and hydroboration – with visible light as the sole trigger. This dichotomy arises from ligand photodissociation which leads to metamorphosis of the active catalytic site, resulting in divergent mechanistic pathways.</p><p></p><p></p>


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