scholarly journals Hydrothermal Synthesis of Cellulose Nanocrystal-Grafted-Acrylic Acid Aerogels with Superabsorbent Properties

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1168 ◽  
Author(s):  
Xuehua Liu ◽  
Rue Yang ◽  
Mincong Xu ◽  
Chunhui Ma ◽  
Wei Li ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Environmental Remediation ◽  
Freeze Drying ◽  
Treatment Time ◽  
Hydrothermal Process ◽  
Cellulose Nanocrystal ◽  
Maximum Adsorption Capacity ◽  
Simple Method ◽  
Hydrothermal Treatment Time

In this work, we applied a fast and simple method to synthesize cellulose nanocrystal (CNC) aerogels, via a hydrothermal strategy followed by freeze drying. The characteristics and morphology of the obtained CNC-g-AA aerogels were affected by the hydrothermal treatment time, volume of added AA (acrylic acid), and the mass fraction of the CNCs. The formation mechanism of the aerogels involved free radical graft copolymerization of AA and CNCs with the cross-linker N,N′-methylene bis(acrylamide) (MBA) during the hydrothermal process. The swelling ratio of the CNC-g-AA aerogels was as high as 495:1, which is considerably greater than that of other polysaccharide-g-AA aerogels systems. Moreover, the CNC-g-AA aerogels exhibited an excellent methyl blue (MB) adsorption capacity and the ability to undergo rapid desorption/regeneration. The maximum adsorption capacity of the CNC-g-AA aerogels for MB was greater than 400 mg/g. Excellent regeneration performance further indicates the promise of our CNC-g-AA aerogels as an adsorbent for applications in environmental remediation.

scholarly journals Fabrication of Cellulose Nanocrystal-g-Poly(Acrylic Acid-Co-Acrylamide) Aerogels for Efficient Pb(II) Removal

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 333 ◽  
Author(s):  
Yifan Chen ◽  
Qian Li ◽  
Yujie Li ◽  
Qijun Zhang ◽  
Jingda Huang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Langmuir Model ◽  
Cellulose Nanocrystal ◽  
Effective Removal ◽  
Pseudo Second Order ◽  
Repeated Use ◽  
Adsorption Desorption ◽  
Hydrolysis Of ◽  
Poly Acrylic Acid

In this work, cellulose nanocrystals (CNCs) obtained by the acid hydrolysis of waste bamboo powder were used to synthesize cellulose nanocrystal-g-poly(acrylic acid-co-acrylamide) (CNC-g-P(AA/AM)) aerogels via graft copolymerization followed by freeze-drying. The structure and morphology of the resulting aerogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the CNC-g-P(AA/AM) aerogels exhibited excellent absorbent properties and adsorption capacities. Subsequent Pb(II) adsorption studies showed that the kinetic data followed the pseudo-second-order equation, while the adsorption isotherms were best described using the Langmuir model. The maximum Pb(II) adsorption capacity calculated by the Langmuir model reached up to 366.3 mg/g, which is a capacity that outperformed that of the pure CNC aerogel. The CNC-g-P (AA/AM) aerogels become structurally stable through chemical cross-linking, which enabled them to be easily regenerated in HCl solution and retain the adsorption capacity after repeated use. The aerogels were found to maintain 81.3% removal efficiency after five consecutive adsorption–desorption cycles. Therefore, this study demonstrated an effective method for the fabrication of an aerogel adsorbent with an excellent reusability in the effective removal of Pb(II) from aqueous solutions.

scholarly journals Preparation of Poly (Acrylic Acid-Acrylamide/Starch) Composite and Its Adsorption Properties for Mercury (II)

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3277
Author(s):  
Wenjuan Zhu ◽  
Zhiyong Yang ◽  
Akram Yasin ◽  
Yanxia Liu ◽  
Letao Zhang
Keyword(s):  
Particle Size ◽  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Graft Copolymer ◽  
Ph Value ◽  
Adsorption Properties ◽  
Size Exclusion ◽  
Narrow Particle Size Distribution ◽  
Maximum Adsorption Capacity ◽  
Poly Acrylic Acid

The poly (acrylic acid-acrylamide/starch) composite was synthesized by solution polymerization, aiming to adsorb mercury (II) in water. The resulted copolymer was characterized by particle size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), scanning electron microscopy (SEM) and dynamic light scattering particle size analyzer (DLS). It turned out that starch was successfully incorporated with the macromolecular polymer matrix and played a key role for improving the performance of the composites. These characterization results showed that the graft copolymer exhibited narrow molecular weight distribution, rough but uniform morphology, good thermal stability and narrow particle size distribution. The graft copolymer was used to remove Hg(II) ions from aqueous solution. The effects of contact time, pH value, initial mercury (II) concentration and temperature on the adsorption capacity of Hg(II) ions were researched. It was found that after 120 min of interaction, poly (acrylic acid-acrylamide/starch) composite achieved the maximum adsorption capacity of 19.23 mg·g−1 to Hg(II) ions with initial concentration of 15 mg·L−1, pH of 5.5 at 45 °C. Compared with other studies with the same purpose, the composites synthesized in this study present high adsorption properties for Hg(II) ion in dilute solution. The adsorption kinetics of Hg(II) on the poly (acrylic acid-acrylamide/starch) composite fits well with the pseudo second order model.

scholarly journals Application of feed-forward and recurrent neural network in modelling the adsorption of boron by amidoxime-modified poly(Acrylonitrile-co-Acrylic Acid)

2019 ◽  
Vol 25 (6) ◽  
pp. 830-840 ◽  
Author(s):  
Lau Kia Li ◽  
Siti Nurul Ain Md Jamil ◽  
Luqman Chuah Abdullah ◽  
Nik Nor Liyana Nik Ibrahim ◽  
Adeyi Abel Adekanm ◽  
...  
Keyword(s):  
Neural Network ◽  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Prediction Models ◽  
Least Square ◽  
Maximum Adsorption Capacity ◽  
Good Prediction ◽  
Feed Forward ◽  
Poly Acrylonitrile ◽  
Boron Adsorption

This research reports application of artificial neural network (ANN) in investigation and optimisation of boron adsorption capacity in aqueous solution using amidoxime-modified poly(acrylonitrile-<i>co</i>-acrylic acid) (AO-modified poly(AN-<i>co</i>-AA)). Both feed-forward and recurrent ANN have been utilized to predict the adsorption potential of synthesised polymer. Three operational parameters, which are adsorbent dosage, initial pH and initial boron concentration during adsorption process were designed to study their effects on the removal capacity. The ANN was trained from experimental data and serviced to optimize, develop and create various prediction models in the process of boron adsorption by AO-modified poly(AN-<i>co</i>-AA). Among several models, radial basis function (RBF) with orthogonal least square (OLS) algorithm displayed good prediction on boron adsorption capacity with mean square error (MSE) and coefficient of determination (R<sup>2</sup>) at 0.000209 and 0.9985, respectively. With desirable the MSE and R<sup>2</sup> values, ANN worked as a promising prediction tool that was able to generate good estimate. The simulated maximum adsorption capacity of the synthesized polymer is 15.23 ± 1.05 mg boron/g adsorbent. Besides, from the results of ANN, the AO-modified poly(AN-<i>co</i>-AA) was proven to be a potential adsorbent for the removal of boron in wastewater treatment.

Luminescence Properties of ZnS:Cu,Tm Semiconductor Nanocrystals Synthesize by a Hydrothermal Process

2011 ◽  
Vol 415-417 ◽  
pp. 499-503
Author(s):  
Mei Xin ◽  
Dong Ping Liu ◽  
Nai Sen Yu ◽  
Xiao Hui Qi ◽  
Hui Li
Keyword(s):  
Hydrothermal Treatment ◽  
Emission Intensity ◽  
Treatment Time ◽  
Semiconductor Nanocrystals ◽  
Hydrothermal Process ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Pl Emission ◽  
Hydrothermal Approach ◽  
Hydrothermal Treatment Time

ZnS:Cu,Tm nanocrystal with 15nm cubic structures have been synthesized by hydrothermal approach at 200°C. The photoluminescence (PL) properties and the effect of hydrothermal treatment time on the structure, morphology and PL spectra of ZnS:Cu,Tm samples have been studied. The as-obtained samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and FT-IR spectra.The result indicated that the PL emission spectrum of codoped with Cu and Tm sample compares with undoped ZnS and doped with Cu alone samples has a significant changes, while the PL emission peak has red shift and PL emission intensity increased. The samples size and crystallization are increase with extending of the treatment time. However, when the hydrothermal treatment time is too long(>12h), the PL emission intensity of sample instead of decreased. Demonstrated changes in surface state of nanomaterials have a greater impact on its luminescence properties.

scholarly journals Synthesis, characterization and adsorption studies of an acrylic acid-grafted sodium alginate-based TiO2 hydrogel nanocomposite

2017 ◽  
Vol 36 (1-2) ◽  
pp. 458-477 ◽  
Author(s):  
Sourbh Thakur ◽  
Omotayo Arotiba
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Methyl Violet ◽  
Maximum Adsorption Capacity ◽  
Nanocomposite Hydrogel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order ◽  
Hydrogel Nanocomposite

Hydrogel nanocomposites were synthesized by solution polymerization of acrylic acid in the presence of sodium alginate biopolymer and TiO2 nanoparticle. TiO2 nanoparticle and N, N-methylene-bis-acrylamide was used as an inorganic and organic crosslinker, respectively. The structure and morphology of the nanocomposites were investigated using X-Ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) and thermogravimetric analysis techniques. The nanocomposites hydrogel was used for the adsorption of methyl violet dye from water. The influence of TiO2 nanoparticle, sodium alginate content and grafting on adsorption were studied. The results showed that a pseudo-second-order adsorption kinetic was predominant in the adsorption of methyl violet onto the nanocomposite hydrogel. The experimental equilibrated adsorption capacity of the nanocomposite hydrogel agrees with Langmuir isotherm. Maximum adsorption capacity of 1156.61 mg g−1 and adsorption efficiency of 99.6% towards methyl violet were obtained for the hydrogel nanocomposite.

Removal of crystal violet from water by poly acrylonitrile-co-sodium methallyl sulfonate (AN69) and poly acrylic acid (PAA) synthetic membranes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ely Cheikh S’Id ◽  
Mohamed Degué ◽  
Chlouma Khalifa ◽  
Chamekh M’Bareck
Keyword(s):  
Acrylic Acid ◽  
Adsorption Capacity ◽  
Crystal Violet ◽  
Electrostatic Interactions ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Dye Molecules ◽  
Membrane Composition ◽  
Poly Acrylonitrile ◽  
Poly Acrylic Acid

Abstract The current investigation is focused on the removal of crystal violet (CV) from water by adsorption process (bach method). To achieve this purpose, specific membranes were prepared from poly acrylonitrile-co-sodium methallyl sulfonate (AN69) and poly acrylic acid (PAA) blends. The adsorption of CV onto AN69/PAA membranes was studied under various conditions: membrane composition, pH, contact time, initial concentration and temperature. To understand the effect of membrane morphology on adsorption process, scanning electronic microscopy (SEM) was employed to determine the features of section and membrane’s surface. From isotherm results, it was found that: the maximum adsorption capacity Q m was 1250 mg g−1, the Langmuir separation factor R L was lying between 0.33 and 0.76, the Freundlich intensity was higher than Unit (n = 1.25) and the adsorption process follows preferentially the Langmuir model (correlation constant R 2 = 0.99). The mechanism of adsorption is perfectly fitted by pseudo second order. The obtained results tend to confirm that the removal of dye molecules is due to the establishment of strong electrostatic interactions between cationic dye molecules and anionic membrane groups. The high adsorption capacity (1250 mg g−1) for the small dye molecules may open wide opportunities to apply these membranes in the removal of various hazardous pollutants commonly present in water.

scholarly journals Super Absorbent Polymers in Environmental Remediation

2013 ◽  
Vol 11 (2) ◽  
pp. 223-234
Keyword(s):  
Adsorption Capacity ◽  
Environmental Remediation ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Relative Energy ◽  
Blue Dye ◽  
Maximum Adsorption Capacity ◽  
Batch Mode ◽  
Intraparticle Diffusion Model ◽  
Adsorbent Surface

Laboratory studies reported earlier, have shown very promising results in the selective removal of dyes from aqueous solutions by a commercially available (super absorbent polymer) SAP, Jalshakti® (JS). JS is mesoporous in nature and is a potential adsorbent for the basic dyes studied. This paper presents the adsorption and kinetic studies for the Methylene blue dye (MB) in a batch mode. The equilibrium adsorption capacity increases from 138.9 to 1428.6 mgg-1 as the initial concentration of MB increases from 100-1000 mg l-1. The maximum adsorption capacity obtained is 1200 mgg-1 which is more than the adsorbents reported in literature. The Kf value is 165.3 mg1-(1/n)g-1L1/n. The slope 1/n, ranging between 0 and 1, is indicative of the relative energy distribution on the adsorbent surface (or surface heterogeneity) The kinetics of the adsorption process suggests that the pseudo second order model is predominant. The pore diffusion kinetics as described by intraparticle diffusion model also controls the adsorption process but is not the only rate limiting mechanism.

scholarly journals Heat Carbonization and ZnCl2 Functionalization of Date Stone as an Adsorbent: Optimization of Material Fabrication Parameters and Adsorption Studies

2021 ◽  
Author(s):  
Nesrine Abderrahim ◽  
Ibtissem Boumnijel ◽  
Hédi Ben Amor ◽  
Ridha Djellabi
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Environmental Remediation ◽  
Diffusion Control ◽  
Maximum Adsorption Capacity ◽  
Scanning Calorimetry ◽  
Activation Temperature ◽  
Synthesis Conditions ◽  
Fabrication Parameters

Abstract The scientific community gave a lot attention to prepare adsorbents from different natural agriculture-based materials to be used alternative to commercial activated carbon. However, less studies on the optimization of fabrication parameters to obtain activated carbon with highly surface area and adsorption capacity. Herein, we report the synthesis conditions optimization of adsorbent based on date stone and modified with ZnCl2. To obtain a highly adsorption ability of the materials, three systematic parameters were evaluated such as the activation temperature, activation time and the functionalization ratio by ZnCl2. The optimization study showed that the best factors to fabricate an adsorbent from date stone are 700°C, 120 min and 2.0 (g/g), wherein, the specific surface area was found to be 1036 m2/g. While, the iodine and phenol numbers were 928.5 mg/g and 2.1 mmol/g, respectively. To further understand the effect of synthesis parameters, the raw and the as-synthesized activated carbon were characterized via Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Batch sorption tests to remove MB from water showed a maximum adsorption capacity of 384.6 mg/g using the prepared activated carbon at pH 6 and room temperature (25±2 °C). It was found also that the kinetic adsorption data obeyed the pseudo-second order and, both external diffusion and intra-particle diffusion control the adsorption. Based on the obtained results, the optimization of synthesis conditions through experimental and mobilization studies may help the transfer of technology in terms of agriculture-based materials valorisation towards the environmental remediation.

Hydrothermal Synthesis of ZnO/Zn Composites with Enhanced Photocatalytic Performance

2012 ◽  
Vol 518-523 ◽  
pp. 746-749 ◽  
Author(s):  
Hong Chao Ma ◽  
Shi Yong Yuan ◽  
Ying Huan Fu ◽  
Xiao Li Dong ◽  
Xiu Fang Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Performance ◽  
Treatment Time ◽  
Hydrothermal Process ◽  
Raw Material ◽  
Anthraquinone Dye ◽  
Semiconductor Interfaces ◽  
Ultraviolet Light Irradiation ◽  
Fabrication Procedure ◽  
Hydrothermal Treatment Time

ZnO/Zn composites photocatalysts were prepared by hydrothermal method using Zn powder as raw material, and the morphology, structure, and photocatalytic performance of composites were investigated. The results showed that the ZnO nanoparticles were produced at the surface of Zn metal powder during hydrothermal process. The thickness of ZnO outer layer (internal metal-semiconductor interfaces) can be controlled by varying hydrothermal treatment time. The resulting ZnO/Zn composites exhibit significantly higher photocatalytic activity than that of pure ZnO for degradation of anthraquinone dye (reactive brilliant blue KN-R) aqueous solution under ultraviolet light irradiation. The enhancement of photocatalytic performance of ZnO/Zn composites can be attributed to the formation of internal metal-semiconductor interfaces. The designed fabrication procedure is simple, feasible, and universal for a series of oxide/metal with controlled microstructure and improved performances.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

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