scholarly journals Study on synthesis and adsorption property of porous carbon/Ni nanoparticle composites

Author(s):  
Sailu Xu ◽  
Yuxin Du ◽  
Meiqi Hui ◽  
Zichen Wang ◽  
Junfeng Zhao ◽  
...  

The porous carbon/Ni nanoparticle composite was prepared by a freeze-drying method using NaCl as the template. It was applied in the effect of the concentration, adsorption time, and temperature of adsorption on the adsorption behavior. The kinetic model and the adsorption isothermic fitting results show that the adsorption behavior fits with the pseudo-secondary dynamics and the Langmuir isothermal model, indicating that the adsorption process is monolayer adsorption. Thermodynamic results indicate that the adsorption process is spontaneous physicochemical adsorption. The fitting showed that the porous carbon/Ni nanoparticle composites reach 217.17 mg·g-1, at 313 K indicates good adsorption for Congo red.

RSC Advances ◽  
2019 ◽  
Vol 9 (67) ◽  
pp. 38998-39010 ◽  
Author(s):  
Weiwei Lan ◽  
Xiumei Zhang ◽  
Mengjie Xu ◽  
Liqin Zhao ◽  
Di Huang ◽  
...  

In this paper, a well-developed porous carbon nanotube (CNT) reinforced polyvinyl alcohol/biphasic calcium phosphate (PVA/BCP) scaffold was fabricated by a freeze-thawing and freeze-drying method.


2021 ◽  
Author(s):  
Ran Chen ◽  
Junjun Wang ◽  
Ling Fan ◽  
Linlin Cui ◽  
Yejuan Zhang ◽  
...  

Abstract To solve the problem of harvesting microalgae during heavy metal adsorption, six different carriers were selected in this study to compare the adsorption behavior of microalgae after immobilization. The optimal immobilized carrier-chitosan was obtained under the following conditions of chitosan: acetic acid (2:40), microalgae concentration (10 8 cells/mL), and immobilization time (18 h). The optimal adsorption conditions were as follows: temperature: 30°C, pH: 5.0, adsorption dose: 1.5 g/L, initial ion concentration: 40 mg/L. Fourier transform infrared spectroscopy analysis showed that the specific functional groups of the specific microalgae played an important role in the adsorption process. The kinetic and isothermal model data showed that the adsorption process was mainly chemical adsorption and homogeneous monolayer adsorption. Moreover, X-ray photoelectron spectroscopy analysis showed that the Cr adsorption process involves the reduction of Cr(VI) to Cr(III).


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2644
Author(s):  
Jan Oszmiański ◽  
Sabina Lachowicz ◽  
Paulina Nowicka ◽  
Paweł Rubiński ◽  
Tomasz Cebulak

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4483
Author(s):  
Yuyingnan Liu ◽  
Xinrui Xu ◽  
Bin Qu ◽  
Xiaofeng Liu ◽  
Weiming Yi ◽  
...  

In this study, corn cob was used as raw material and modified methods employing KOH and KMnO4 were used to prepare activated carbon with high adsorption capacity for mercury ions. Experiments on the effects of different influencing factors on the adsorption of mercury ions were undertaken. The results showed that when modified with KOH, the optimal adsorption time was 120 min, the optimum pH was 4; when modified with KMnO4, the optimal adsorption time was 60 min, the optimal pH was 3, and the optimal amount of adsorbent and the initial concentration were both 0.40 g/L and 100 mg/L under both modified conditions. The adsorption process conforms to the pseudo-second-order kinetic model and Langmuir model. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Zeta potential characterization results showed that the adsorption process is mainly physical adsorption, surface complexation and ion exchange.


Chemosphere ◽  
2021 ◽  
pp. 129504
Author(s):  
Sami Ullah ◽  
Abdullah G. Al-Sehemi ◽  
Muhammad Mubashir ◽  
Ahmad Mukhtar ◽  
Sidra Saqib ◽  
...  

2020 ◽  
Vol 18 (1) ◽  
pp. 584-590 ◽  
Author(s):  
◽  
Dyah Hikmawati ◽  
Umi Kulsum ◽  
Djony Izak Rudyardjo ◽  
Retna Apsari ◽  
...  

AbstractThe synthesis of collagen–hydroxyapatite composites has been carried out, and the biocompatibility and osteoconductivity properties have been tested. This research was conducted to determine the ability of hydroxyapatite–collagen composites to support the bone growth through the graft surface. Hydroxyapatite used in this study was synthesized from coral with a purity of 96.6%, while collagen was extracted from the chicken claw. The process of forming a scaffold of collagen–hydroxyapatite composites was carried out using the freeze-drying method at −80°C for 4 h. The biocompatibility characteristics of the sample through the cytotoxicity tests showed that the percentage of viable cells in collagen–hydroxyapatite biocomposite was 108.2%, which is higher than the percentage of viable cells of hydroxyapatite or collagen material. When the viable cell is above 100%, collagen–hydroxyapatite composites have excellent osteoconductivity as a material for bone regeneration.


2019 ◽  
Vol 32 (1) ◽  
pp. 73-78
Author(s):  
P. Janaki ◽  
R. Sudha ◽  
T.S. Sribharathi ◽  
P. Anitha ◽  
K. Poornima ◽  
...  

The adsorption performance of sulphuric acid treated low cost adsorbent synthesized by using Citrus limettioides peel as an effective raw material for the removal of cadmium(II) from water. The batch adsorption method was carried out to optimize some parameters like contact time, pH and adsorbent dose. The nonlinear isotherm equations were used to calculate the different isotherm constant of five isotherm models namely Freundlich, Langmuir, Dubinin-Radushkevich, Redlich-Peterson and Sips. The Langmuir monolayer adsorption capacity of chemically modified Citrus limettioides peel was found to be 287.60 mg g-1. The negative values of ΔGº and ΔHº showed that the adsorption process is spontaneous and exothermic.


2021 ◽  
Author(s):  
Yunqi Wang ◽  
Zhixiang Liu ◽  
Xu Tang ◽  
Pengwei Huo ◽  
Zhi Zhu ◽  
...  

A P-CN/CsPbBr3 photocatalyst with a lamellar porous structure was prepared by a high temperature calcination and freeze drying method, and it exhibited superior CO2 reduction performance under the conditions of full spectrum irradiation.


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