Microwave carbonization of cotton fiber for the production of carbon materials

2021 ◽  
Vol 11 ◽  
pp. 54-68
Author(s):  
E. V. Matveev ◽  
◽  
A. I. Gajdar ◽  
B. A. Lapshinov ◽  
A. V. Mamontov ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Fiber Surface ◽  
Thermal Method ◽  
Surface Layers ◽  
Cotton Lint ◽  
Microwave Exposure ◽  
Carbonization Process ◽  
Fiber Wall ◽  
Physico Chemical ◽  
Transverse Fractures

This article presents the results of comparative studies of the structural and physico-chemical features of cotton lint samples carbonized by the microwave method and the standard (thermal) method. The dependences of the temperature change of the samples during the microwave carbonization process are obtained. The heterogeneity of the morphology of the fiber surface along the cross-section of the microwave carbonized sample was revealed. It is shown that the structure of the surface layers is characterized by two mechanisms of fiber destruction: numerous brittle transverse fractures and coloring of the fibers in places of swellings (a sharp increase in their diameter) and fluffing of the surface into convoluted fibrils with a transverse size of 50 – 300 nm due to the destruction of the outer layers of the secondary fiber wall. In the central region, the destruction of fibers occurs by the formation of longitudinal interfibrillary slits and the delamination of the secondary fiber wall, which leads to the formation of pores with dimensions of 50 – 200 nm. It is established that during the microwave carbonization process, the central part of the sample is almost completely freed from impurities that are deposited on the fibers of the surface layers. It is shown that the integral adsorption capacity of the microwave carbonized sample is higher than the adsorption capacity of the sample carbonized by the thermal method (126 mg/g and 47 mg/g, respectively). It was found that during microwave exposure more than 10 minutes, regions with an adsorption capacity of ~ 350 – 450 mg/g appear in the carbonized material, that is comparable to the capacity of samples activated by the standard method.

scholarly journals Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liqiang Cui ◽  
Qinya Fan ◽  
Jianxiong Sun ◽  
Guixiang Quan ◽  
Jinlong Yan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Properties ◽  
Aging Process ◽  
Surface Characteristics ◽  
Natural Soil ◽  
Peanut Shell ◽  
Soil Environment ◽  
Polluted Soils ◽  
Physico Chemical

AbstractFenton-like system formed in a natural soil environment deemed to be significant in the aging process of biochar. Aged biochars have distinct physico-chemical and surface properties compared to non-aged biochar. The aged biochar proved to be useful soil amendment due to its improved elements contents and surface properties. The biochar aging process resulted in increased surface area and pore volume, as well as carbon and oxygen-containing functional groups (such as C=O, –COOH, O–C=O etc.) on its surface, which were also associated with the adsorption behavior of 2,4,6-trichlorophenol (2,4,6-TCP). The biochar aging increased the adsorption capacity of 2,4,6-TCP, which was maximum at pH 3.0. The 2,4,6-TCP adsorption capacity of aged-bush biochar (ABB) and aged-peanut shell biochar (APB) was increased by 1.0–11.0% and 7.4–38.8%, respectively compared with bush biochar (BB) and peanut shell biochar (PB) at the same initial concentration of 2,4,6-TCP. All biochars had similar 2,4,6-TCP desorption rates ranging from 33.2 to 73.3% at different sorption temperatures and times. The desorbed components were mainly 2,4,6-TCP and other degraded components, which were low in concentration with small molecule substance. The results indicated that the aged-biochar could be effective for the long-term remediation of naturally organic polluted soils.

scholarly journals Diurnal vertical migration of some cladocerans in relation to the physico-chemical factors in a fish pond

1970 ◽  
Vol 20 (2) ◽  
pp. 147-154 ◽  
Author(s):  
AS Bhuiyan ◽  
S Akhter ◽  
MMA Quddus
Keyword(s):  
Key Words ◽  
Vertical Migration ◽  
Fish Pond ◽  
Chemical Parameters ◽  
Surface Layers ◽  
Diurnal Vertical Migration ◽  
Physico Chemical ◽  
Chemical Factors ◽  
Diurnal Movement ◽  
The Relationship

Diurnal vertical migration of four genera of cladocerans, namely Diaphanosoma sp., Daphnia sp., Moina sp. and Bosmina sp., during March to December, 2007 showed that the number of Diaphanosoma sp. was 501 units/1 in the surface layers, 172 units/l in the middle layers and 190 units/l in the bottom layers. The yearly number of Daphnia sp. in surface, middle and bottom layerss was 362 units/l, 46 units/l and 189 units/l respectively. In surface, bottom and middle layers, the number of Moina sp. was 159, 71 and 32 units/l, respectively. Bosmina sp. was 78 units/l in surface, 31 units/l in the middle and 33 units/l in the bottom layers. The number of Diaphanosoma sp., Daphnia sp., Moina sp., Bosmina sp., were 455, 149, 259 and 358 units/l, respectively in the morning, 63, 176, 142, 43 units/l at noon and 107, 55, 28, 59 units/l, respectively in the evening. Throughout the study period the cladocerans were always abundant near the surface during morning and evening. Among the factors responsible for the diurnal movement of cadoceran, light played the most important factor. The relationship between the physico-chemical factors and the cladoceran occurrence in the pond was also explored. Key words: Cladocera; Diurnal migration; Physico-chemical parameters; Fish pond DOI: http://dx.doi.org/10.3329/dujbs.v20i2.8975 DUJBS 2011; 20(2): 147-154

scholarly journals Dysprosium Removal from Water Using Active Carbons Obtained from Spent Coffee Ground

2019 ◽  
Author(s):  
Lorena Alcaraz ◽  
María Esther Escudero ◽  
Francisco J. Alguacil ◽  
Irene Llorente ◽  
Ana Urbieta ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Chemical Study ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Microporous Material ◽  
Physico Chemical ◽  
Spent Coffee Ground ◽  
Coffee Ground

This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.

Physico-chemical modification of natural mordenite-clinoptilolite zeolites and their enhanced CO2 adsorption capacity

2020 ◽  
Vol 294 ◽  
pp. 109871 ◽  
Author(s):  
Satriyo Krido Wahono ◽  
Joseph Stalin ◽  
Jonas Addai-Mensah ◽  
William Skinner ◽  
Ajayan Vinu ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Adsorption Capacity ◽  
Co2 Adsorption ◽  
Physico Chemical ◽  
Co2 Adsorption Capacity

Deciphering the Adsorption Behavior of Volatile Organic Compounds with Electrospun Polyacrylonitrile/Molecular Sieve Nanocomposites

2019 ◽  
Vol 19 (11) ◽  
pp. 7315-7319 ◽  
Author(s):  
Yi-Xin Wang ◽  
Hong Tao ◽  
Min-Nan Chen ◽  
Ling-Shao ◽  
Guang-Feng Shang ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Adsorption Capacity ◽  
Organic Compounds ◽  
Molecular Sieve ◽  
Fiber Surface ◽  
Polyacrylonitrile Fiber ◽  
Volatile Organic ◽  
New Type ◽  
Short Time ◽  
Adsorption Desorption

In this study, a new type of molecular sieve/polyacrylonitrile fiber (M-PAN) was prepared by electrospinning to adsorb atmospheric volatile organic compounds (VOCs). The suitable content of molecular sieve in nanocomposites was also determined for achieving maximum VOCs adsorption capacity. SEM, TEM and N2 adsorption/desorption analyzer were performed for characterization of the surface morphology, structural properties, surface area and pore size. A part of molecular sieve is exposed on the fiber surface where VOCs can be adsorbed efficiently in a short time. Acetone was used as a challenge pollutant to evaluate the adsorption of VOCs at different recycling times and types of electrospinning nanofibers. The adsorption capacity of 6M-PAN (60% weight of molecular sieve) nanofiber reached 58.2 μg g−1 and the reused nanofibers nearly had the same adsorption capacity as the newly prepared nanofibers after several times of recirculation.

Metaplexis japonicaseed hair fiber: a member of natural hollow fibers and its characterization

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4363-4372 ◽  
Author(s):  
Zongqian Wang ◽  
Dengfeng Wang ◽  
Mingrong Wang ◽  
Wei Li ◽  
Qing Sui
Keyword(s):  
Length Distribution ◽  
Hollow Structure ◽  
Fiber Surface ◽  
Surface Characteristics ◽  
Extensive Study ◽  
Research Literature ◽  
Retention Performance ◽  
Fiber Morphology ◽  
Surface Absorption ◽  
Fiber Wall

Metaplexis japonica seed hair fibers (Mj-fiber), harvested from the seed pods of Metaplexis japonica (Apocynaceae: Asclepiadoideae) originating in China, Japan and Korea, have features ensuring its potential application in the textile and other industrial fields. In spite of the extensive study on the medicinal properties of Metaplexis japonica, research literature about Mj-fiber is quite limited. We obtained Mj-fibers by artificial peeling and seed removing; then the fiber morphology, chemical composition, structures, fiber surface absorption characteristics, and tensile and thermal properties were studied in detail. From the results, Mj-fiber has a hollow structure with a thin fiber wall and large lumen, in which the hollowness is over 92%. Uniquely, Mj-fiber is a natural profiled fiber with a cross-section of a "cross flower" morphology. At the same time, the density of it is very low, accounting for only one-fifth of the cotton fibers, and the fiber length distribution is relatively concentrated. The main component is cellulose, with a content of 53.9 ± 3.20% and structure of cellulose I. In particular, Mj-fiber has excellent hydrophobic and oil affinity surface characteristics. Moreover, the fibers bulkiness and warmth retention performance are comparable to that of duck down. Therefore, the results provide an experimental basis for the application of Mj-fibers in the textile and other industrial fields.

scholarly journals In-situ Preparation of Nano-calcium Carbonate/Cellulose Fiber Composite and Its Application in Fluff Pulp

2017 ◽  
Vol 12 (3) ◽  
pp. 155892501701200 ◽  
Author(s):  
Yongjian Xu ◽  
Chunmei Jiang ◽  
Chao Duan ◽  
Weipeng Zhang
Keyword(s):  
Hydrogen Bonding ◽  
Calcium Carbonate ◽  
Adsorption Capacity ◽  
Fiber Composite ◽  
Fiber Surface ◽  
Cellulose Fiber ◽  
Natural Polymers ◽  
Inorganic Particles ◽  
In Situ Preparation

Calcium carbonate/cellulose fiber composites combining natural polymers and inorganic particles are promising materials for preparing fluff pulp. In this study, calcium carbonate (CaCO3) particles were in-situ precipitated on cellulose fiber surfaces to decrease the level of hydrogen bonding. The results showed that nano CaCO3 particles precipitated and dispersed well on the fiber surface. The fluff pulp made from cellulose/CaCO3 modified fibers exhibited high effectiveness in the dry defibration process and good adsorption capacity due to the weak hydrogen bonding. The burst index of the handsheets decreased 31% (based on the ash content of 1.48 wt. %) without compromising the adsorption capacity of the fluff pulp.

Carbon Fiber Surface Modification by Plasma Treatment for Interface Adhesion Improvements of Aerospace Composites

2016 ◽  
Vol 1135 ◽  
pp. 75-87 ◽  
Author(s):  
Alberto Lima Santos ◽  
Edson Cocchieri Botelho ◽  
Konstantin Georgiev Kostov ◽  
Mario Ueda ◽  
Leide Lili G. da Silva
Keyword(s):  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Fiber Surface ◽  
Polyphenylene Sulfide ◽  
Thermoplastic Composite ◽  
Force Microscopy ◽  
Atomic Force ◽  
Physico Chemical ◽  
Plasma Immersion Ion Implantation ◽  
Interlaminar Shear

This paper is focused on the processing of thermoplastic composite materials obtained from carbon fibers (CFs) treated by plasma assisted techniques. The treatments employed in this work were the Dielectric Barrier Discharge (DBD), which is done at atmospheric pressure, involving lower energies and the Plasma Immersion Ion Implantation (PIII), which is performed at low pressure, involving higher energies. After the treatments, samples characterizations were performed to determine which treatment is most effective to get better physico-chemical CF surface properties. The techniques employed in this work in order to evaluate the surface treatment were: scanning electron microscopy (SEM); atomic force microscopy (AFM) Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). Treated and untreated CFs/Polyphenylene sulfide (PPS) composites were processed by hot-compression molding technique. These composites were evaluated by interlaminar shear tests (ILSS). After analyzing the results, it was found that the treatments increased the CF roughness and caused slight changes in the CF structure. In addition, there was an increase in the shear strength of the composites obtained from treated fibers by both plasma processes. In conclusion, DBD and PIII treatments are effective tools for improving adhesion between CF and the polymeric matrix.

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