scholarly journals Preparation, Characterization, and Evaluation of Macrocrystalline and Nanocrystalline Cellulose as Potential Corrosion Inhibitors for SS316 Alloy during Acid Pickling Process: Experimental and Computational Methods

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2275
Author(s):  
Arafat Toghan ◽  
Mohamed Gouda ◽  
Kamal Shalabi ◽  
Hany M. Abd El-Lateef

Converting low-cost bio-plant residuals into high-value reusable nanomaterials such as microcrystalline cellulose is an important technological and environmental challenge. In this report, nanocrystalline cellulose (NCC) was prepared by acid hydrolysis of macrocrystalline cellulose (CEL). The newly synthesized nanomaterials were fully characterized using spectroscopic and microscopic techniques including FE-SEM, FT-IR, TEM, Raman spectroscopy, and BET surface area. Morphological portrayal showed the rod-shaped structure for NCC with an average diameter of 10–25 nm in thickness as well as length 100–200 nm. The BET surface area of pure CEL and NCC was found to be 10.41 and 27 m2/g, respectively. The comparative protection capacity of natural polymers CEL and NCC towards improving the SS316 alloy corrosion resistance has been assessed during the acid pickling process by electrochemical (OCP, PDP, and EIS), and weight loss (WL) measurements. The outcomes attained from the various empirical methods were matched and exhibited that the protective efficacy of these polymers augmented with the upsurge in dose in this order CEL (93.1%) < NCC (96.3%). The examined polymers display mixed-corrosion inhibition type features by hindering the active centers on the metal interface, and their adsorption followed the Langmuir isotherm model. Surface morphology analyses by SEM reinforced the adsorption of polymers on the metal substrate. The Density Functional Theory (DFT) parameters were intended and exhibited the anti-corrosive characteristics of CEL and NCC polymers. A Monte Carlo (MC) simulation study revealed that CEL and NCC polymers are resolutely adsorbed on the SS316 alloy surface and forming a powerful adsorbed protective layer.

In this paper, easy, rapid and cheap synthetic method was described for florfenicol-silver nanocomposite by sonochemical method. Florfenicol-silver nanocomposite was characterized based on three classes namely index, identification and morphology class. Index characterization was carried out by zeta sizing, BET surface area and zeta potential. Identification characterization was performed using X-ray diffraction (XRD) and Raman spectrometry. Morphology characterization was done utilizing transmission electron microscope (TEM), scanning electron microscope (SEM) and atomic force microscope (AFM). Characterization results showed zeta sizing of florfenicol was 30.44nm, while florfenicol-silver nanocomposite was 33.5 nm with zeta potential -14.1 and -18, respectively. BET surface area was found to be 13.3, 73.2 and 103.69 m2/g for florfenicol, silver nanoparticles and florfenicol-silver nanocomposite respectively. XRD and Raman charts confirmed the formation of florfenicol-silver nanocomposite without any contamination. TEM, SEM and AFM spectral data illustrated spherical to sub spherical shape of silver nanoparticles on cubic to sheet shape of florfenicol with size less than 50 nm. Antimicrobial activity was screened where the average zone of inhibitions caused by the prepared nanocomposite were 28.3 mm, 24 mm, 27.3 mm and 24 mm compared to 17.7 mm, 16 mm, 18.7 mm and 13.3 mm of the native drug and 13 mm, 10 mm, 14.3 mm and 15 mm of the used positive reference standards against E. coli, Salmonella typhymurium, Staphylococcus aureus and Staph.aureus MRSA respectively.


Author(s):  
Reza Yazdanpanah ◽  
Eshagh Moradiyan ◽  
Rouein Halladj ◽  
Sima Askari

Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time. Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel. Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure. Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2019
Author(s):  
Maria A. Morosanova ◽  
Ksenia V. Chaikun ◽  
Elena I. Morosanova

In order to design a sensor material for total antioxidant capacity determination we have prepared silica and silica–titania xerogels doped with iron(III) and modified with 1,10-phenanthroline. Titanium(IV) tetraethoxyde content in the precursors (titanium(IV) tetraethoxyde and tetraethyl orthosilicate) mixtures has been varied from 0 to 12.5% vol. Iron(III) concentrations in sol has been varied from 1 to 100 mM. The increase of titanium(IV) content has led to a decrease in BET surface area and average pore diameter and an increase of micropore surface area and volume, which has resulted in better iron(III) retention in the xerogels. Iron(III), immobilized in the xerogel matrix, retains its ability to form complexes with 1,10-phenanthroline and to be reduced to iron(II). Static capacities for 1,10-phenanthroline have been determined for all the iron(III) doped xerogels (0.207 mmol/g–0.239 mmol/g) and they are not dependent on the iron(III) content. Sensor materials—xerogels doped with iron(III) and modified with 1,10-phenanthroline—have been used for antioxidants (catechol, gallic and ascorbic acids, and sulphite) solid phase spectrophotometric determination. Limits of detection for catechol, gallic and ascorbic acids, and sulphite equal 7.8 × 10−6 M, 5.4 × 10−6 M, 1.2 × 10−5 M, and 3.1 × 10−4 M, respectively. The increase of titanium(IV) content in sensor material has led to an increase of the reaction rate and the sensitivity of determination. Proposed sensor materials have been applied for total antioxidant capacity (in gallic acid equivalents) determination in soft beverages, have demonstrated high stability, and can be stored up to 6 months at room temperature.


2021 ◽  
Author(s):  
Narendran Rajendran ◽  
Ali A. Husain ◽  
Saad Makhseed

Three new carbazole containing cross-linked polymers namely AH-Poly, TM-PDA-Poly and TMB-PDA-Poly were designed and successfully synthesized by an oxidative polymerization protocol. The prepared AH-Poly showed a specific BET surface area...


2021 ◽  
Author(s):  
Yaping Zhang ◽  
Daofei Lv ◽  
Jiayu Chen ◽  
Zewei Liu ◽  
Chongxiong Duan ◽  
...  

The separation of ethylene/ethane mixture using energy-efficient technologies is important but challenging. Here, we prepared a Zr-based metal-organic framework (MOF-545) possessing high Brunauer-Emmett-Teller (BET) surface area of 2265.4 m2/g, and...


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.


Adsorption ◽  
2020 ◽  
Vol 26 (7) ◽  
pp. 1083-1091
Author(s):  
Mi Tian ◽  
Sébastien Rochat ◽  
Hamish Fawcett ◽  
Andrew D. Burrows ◽  
Christopher R. Bowen ◽  
...  

Abstract A detailed investigation has been carried out of the pre-polymerisation modification of the polymer of intrinsic microporosity PIM-1 by the addition of two methyl (Me) groups to its spirobisindane unit to create a new chemically modified PIM-1 analogue, termed MePIM. Our work explores the effects of this modification on the porosity of PIM-1 and hence on its gas sorption properties. MePIM was successfully synthesised using either low (338 K) or high (423 K) temperature syntheses. It was observed that introduction of methyl groups to the spirobisindane part of PIM-1 generates additional microporous spaces, which significantly increases both surface area and hydrogen storage capacity. The BET surface area (N2 at 77 K) was increased by ~ 12.5%, resulting in a ~ 25% increase of hydrogen adsorption after modification. MePIM also maintains the advantages of good processability and thermal stability. This work provides new insights on a facile polymer modification that enables enhanced gas sorption properties.


2013 ◽  
Vol 594-595 ◽  
pp. 73-77 ◽  
Author(s):  
Sze Mei Chin ◽  
Suriati Sufian ◽  
Jeefferie Abd Razak

This paper highlights on the hydrogen production through photocatalytic activity by using hematite nanoparticles synthesized from self-combustion method based on different stirring period. The morphologies and microstructures of the nanostructures were determined using Field-Emission Scanning Electron Microscope (FESEM), X-Ray Diffractometer (XRD) and Particle Size Analyser (PSA). Besides that, surface area analyser was used to determine the BET surface area of the hematite samples. The hematite nanocatalyst as-synthesized are proven to be rhombohedral crystalline hematite (α-Fe2O3) with particle diameters ranging from 60-140 nm. The BET specific surface area of hematite samples increased from 5.437 to 7.6425 m2/g with increasing stirring period from 1 to 4 weeks. This caused the amount of hydrogen gas produced from photocatalytic water splitting to increase as well.


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