Characteristics of nanocellulose crystals from balsa and kapok fibers at different ammonium persulfate concentrations

2021 ◽  
Author(s):  
Marwanto Marwanto ◽  
Muhammad Iqbal Maulana ◽  
Fauzi Febrianto ◽  
Nyoman J. Wistara ◽  
Siti Nikmatin ◽  
...  
Keyword(s):  
Ammonium Persulfate ◽  
Kapok Fibers

scholarly journals Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1894
Author(s):  
Marwanto Marwanto ◽  
Muhammad Iqbal Maulana ◽  
Fauzi Febrianto ◽  
Nyoman Jaya Wistara ◽  
Siti Nikmatin ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Zeta Potential ◽  
Cellulose Nanocrystals ◽  
Average Diameter ◽  
Ammonium Persulfate ◽  
Oxidation Time ◽  
Sodium Chlorite ◽  
Step Method ◽  
Thermal Stabilities ◽  
Kapok Fibers

This study aimed to evaluate the effect of ammonium persulfate’s (APS) oxidation time on the characteristics of the cellulose nanocrystals (CNCs) of balsa and kapok fibers after delignification pretreatment with sodium chlorite/acetic acid. This two-step method is important for increasing the zeta potential value and achieving higher thermal stability. The fibers were partially delignified using acidified sodium chlorite for four cycles, followed by APS oxidation at 60 °C for 8, 12, and 16 h. The isolated CNCs with a rod-like structure showed an average diameter in the range of 5.5–12.6 nm and an aspect ratio of 14.7–28.2. Increasing the reaction time resulted in a gradual reduction in the CNC dimensions. The higher surface charge of the balsa and kapok CNCs was observed at a longer oxidation time. The CNCs prepared from kapok had the highest colloid stability after oxidation for 16 h (−62.27 mV). The CNCs with higher crystallinity had longer oxidation times. Thermogravimetric analysis revealed that the CNCs with a higher thermal stability had longer oxidation times. All of the parameters were influenced by the oxidation time. This study indicates that APS oxidation for 8–16 h can produce CNCs from delignified balsa and kapok with satisfactory zeta potential values and thermal stabilities.

Urticarial reaction to ammonium persulfate

1972 ◽  
Vol 106 (3) ◽  
pp. 413-414 ◽  
Author(s):  
M. M. Brubaker
Keyword(s):  
Ammonium Persulfate

The Role of the Initiator System in the Synthesis of Acidic Multifunctional Nanoparticles Designed for Molecular Imprinting of Proteins

2020 ◽  
Vol 65 (1) ◽  
pp. 28-41
Author(s):  
Marwa Aly Ahmed ◽  
Júlia Erdőssy ◽  
Viola Horváth
Keyword(s):  
Acrylic Acid ◽  
Binding Affinity ◽  
Molecular Imprinting ◽  
Low Temperatures ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
Multifunctional Nanoparticles ◽  
High Affinity ◽  
Initiator System

Multifunctional nanoparticles have been shown earlier to bind certain proteins with high affinity and the binding affinity could be enhanced by molecular imprinting of the target protein. In this work different initiator systems were used and compared during the synthesis of poly (N-isopropylacrylamide-co-acrylic acid-co-N-tert-butylacrylamide) nanoparticles with respect to their future applicability in molecular imprinting of lysozyme. The decomposition of ammonium persulfate initiator was initiated either thermally at 60 °C or by using redox activators, namely tetramethylethylenediamine or sodium bisulfite at low temperatures. Morphology differences in the resulting nanoparticles have been revealed using scanning electron microscopy and dynamic light scattering. During polymerization the conversion of each monomer was followed in time. Striking differences were demonstrated in the incorporation rate of acrylic acid between the tetramethylethylenediamine catalyzed initiation and the other systems. This led to a completely different nanoparticle microstructure the consequence of which was the distinctly lower lysozyme binding affinity. On the contrary, the use of sodium bisulfite activation resulted in similar nanoparticle structural homogeneity and protein binding affinity as the thermal initiation.

Iono-molecular Separation with Composite Membranes II. Preparation and characterization of polysulphone and composite nanoparticles

2017 ◽  
Vol 68 (2) ◽  
pp. 203-209
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Corneliu Trisca-Rusu ◽  
Szidonia Katalin Tanczos ◽  
Adriana Cuciureanu ◽  
...  
Keyword(s):  
Chemical Species ◽  
Composite Membranes ◽  
Ammonium Persulfate ◽  
Operating Pressure ◽  
Polysulfone Membrane ◽  
Polymeric Nanoparticle ◽  
Molecular Separation ◽  
Copper Complexation ◽  
Molecular Separations ◽  
Methyl Pyrrolidone

This paper illustrates the possibility of producing iono-molecular separations using ionic colloidal ultrafiltration membrane of polysulfone synthetic solutions of cupric ions and nitro phenols through ultrafiltration assisted by polymeric nanoparticle composites based on polysulfone. In the present work, in order to reduce the operating pressure and increase the flow of water we are using the process of ultrafiltration through a polysulfone membrane in N-methylpyrrolidone 10% prepared by coagulation in isopropanol. The nanoparticles needed in colloidal ultrafiltration had been obtained through the immersion technique of precipitation of a solution of 5% PSf in N-methyl pyrrolidone containing 3% aniline in lower alcohols: methanol, ethanol, and isopropanol, followed by the oxidation of the remaining aniline in a solution of 10% hydrochloric acid and ammonium persulfate. The Nanoparticles of polysulfone (NP-PSf) and The three obtained variants of nanoparticles composites (NP-PSf-PANI) were morphologically (SEM) and (AFM), structurally and compositionally (FTIR) characterized and the results show that nanoparticles polysulfone have a much lower range than the composites. The Possibility of copper complexation by both nitrophenols, and by nanoparticle surface probably lead to the formation of more stable aggregates in the supply, which can sufficiently justify the increased retention. The Retentions of the chemical species in question use in all the tests made the same series:R NP-PSf-PANI-M] R NP-PSf-PANI-E] R NP-PSf-PANI-P] R NP-PSf

scholarly journals A Facile Method to Realize Oxygen Reduction at the Hydrogen Evolution Cathode of an Electrolytic Cell for Energy-Efficient Electrooxidation

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2841
Author(s):  
Zhiqiang Zhao ◽  
Lu Liu ◽  
Luofu Min ◽  
Wen Zhang ◽  
Yuxin Wang
Keyword(s):  
Oxygen Reduction ◽  
Electrochemical Oxidation ◽  
Hydrogen Evolution ◽  
Low Cost ◽  
Pollution Abatement ◽  
Electric Energy ◽  
Ammonium Persulfate ◽  
Electrolytic Cell ◽  
Reduction Reaction ◽  
Explosion Hazard

Electrochemical oxidation, widely used in green production and pollution abatement, is often accompanied by the hydrogen evolution reaction (HER), which results in a high consumption of electricity and is a potential explosion hazard. To solve this problem, we report here a method for converting the original HER cathode into one that enables the oxygen reduction reaction (ORR) without having to build new electrolysis cells or be concerned about electrolyte leakage from the O2 gas electrode. The viability of this method is demonstrated using the electrolytic production of ammonium persulfate (APS) as an example. The original carbon black electrode for the HER is converted to an ORR electrode by first undergoing in situ anodization and then contacting O2 or air bubbled from the bottom of the electrode. With this sole change, APS production can achieve an electric energy saving of up to 20.3%. Considering the ease and low cost of this modification, such significant electricity savings make this method very promising in the upgrade of electrochemical oxidation processes, with wide potential applications.

scholarly journals Performance Evaluation of Enzyme Breaker for Fracturing Applications under Simulated Reservoir Conditions

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3133
Author(s):  
Yuling Meng ◽  
Fei Zhao ◽  
Xianwei Jin ◽  
Yun Feng ◽  
Gangzheng Sun ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Shear Resistance ◽  
Ammonium Persulfate ◽  
Fracturing Fluid ◽  
Medium Temperature ◽  
Fracture Conductivity ◽  
Wide Range ◽  
Reservoir Conditions ◽  
Alkaline Conditions ◽  
Resistance Performance

Fracturing fluids are being increasingly used for viscosity development and proppant transport during hydraulic fracturing operations. Furthermore, the breaker is an important additive in fracturing fluid to extensively degrade the polymer mass after fracturing operations, thereby maximizing fracture conductivity and minimizing residual damaging materials. In this study, the efficacy of different enzyme breakers was examined in alkaline and medium-temperature reservoirs. The parameters considered were the effect of the breaker on shear resistance performance and sand-suspending performance of the fracturing fluid, its damage to the reservoir after gel breaking, and its gel-breaking efficiency. The experimental results verified that mannanase II is an enzyme breaker with excellent gel-breaking performance at medium temperatures and alkaline conditions. In addition, mannanase II did not adversely affect the shear resistance performance and sand-suspending performance of the fracturing fluid during hydraulic fracturing. For the same gel-breaking result, the concentration of mannanase II used was only one fifth of other enzyme breakers (e.g., mannanase I, galactosidase, and amylase). Moreover, the amount of residue and the particle size of the residues generated were also significantly lower than those of the ammonium persulfate breaker. Finally, we also examined the viscosity-reducing capability of mannanase II under a wide range of temperatures (104–158 °F) and pH values (7–8.5) to recommend its best-use concentrations under different fracturing conditions. The mannanase has potential for applications in low-permeability oilfield development and to maximize long-term productivity from unconventional oilwells.

Graft Copolymerization of Acrylamide onto Activated Starch Using Inverse Emulsion Polymerization

2011 ◽  
Vol 308-310 ◽  
pp. 600-605
Author(s):  
Dian Mo Zheng ◽  
Sheng Gan Zhu ◽  
Li Ping Wu
Keyword(s):  
Ball Milling ◽  
Graft Copolymerization ◽  
Chemical Reactivity ◽  
Weight Ratio ◽  
Monomer Conversion ◽  
Ammonium Persulfate ◽  
Grafting Efficiency ◽  
Inverse Emulsion ◽  
Initiation System ◽  
Ft Ir

Activated starch was prepared by ball milling before used. Graft copolymerization of acrylamide onto activated starch was carried out in inverse emulsion using a redox initiation system of ammonium persulfate and sodium bisulfite. The effects of ball-milling time, reaction temperature, initiator concentration and weight ratio of acrylamide to starch on the conversion of monomer, grafting percentage and grafting efficiency were studied. The structure and properties of the graft copolymer and activated starch were characterized by FT-IR, XRD and SEM. The results showed that ball milling could progressively destroy the crystalline structure of starch and improve the chemical reactivity. The monomer conversion, grafting percentage and grafting efficiency of grate copolymerization were 96.6%、62.4%、85.49%, respectively.

Preparation and Characterization of Polyaniline Nanotubes Doped with Different Acid

2013 ◽  
Vol 401-403 ◽  
pp. 663-666
Author(s):  
Xue Lian Bai ◽  
Jian Ting Mei ◽  
Zhong Guo Mu ◽  
Yun Bai
Keyword(s):  
Acetic Acid ◽  
Self Assembly ◽  
Ammonium Persulfate ◽  
Tetraacetic Acid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Property ◽  
Assembly Method ◽  
Polyaniline Nanotubes

Polyaniline (PANI) nanotubes were synthesized separately using amino acetic acid (AA), ethylenediamine tetraacetic acid (EDTA), oxalic acid (OA) as dopant and ammonium persulfate (APS) as oxidant by a self-assembly method. SEM, TEM,FTIR and X-ray diffraction (XRD) and applying the 4 probes method characterized the morphology, structure and property of the product. It was found that nanotubes morphology were synthesized when the [Aci/[A ratio is 1:2.The room template conductivity of the products were studied.

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