A ribbon-like ultramicroporous conjugated polycarbazole network for gas storage and separation

2016 ◽  
Vol 40 (4) ◽  
pp. 3172-3176 ◽  
Author(s):  
Shanlin Qiao ◽  
Huan Wei ◽  
Ting Wang ◽  
Wei Huang ◽  
Chunyang Gu ◽  
...  

Ribbon-like ultramicroporous conjugated polycarbazole network P-TCzTAT was synthesized having high BET surface area and narrow pore width distribution.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wen Liu ◽  
Tong-Tong Wang ◽  
Xiao-Luan Tang ◽  
Fei-Ya Jiang ◽  
Xiao Yan ◽  
...  

In this work, quercetin was loaded in the highly-porous lactose via the adsorption of quercetin molecules in ethanol. The method aims to improve the quercetin solubility and the loading capacity of lactose. The method relates to the synthesis of the highly-porous lactose with a particle size of ∼35 μm, a mean pore width of ∼30 nm, a BET surface area of 35.0561 ± 0.4613 m2/g, and a BJH pore volume of ∼0.075346 cc/g. After the quercetin loading in ethanol, BET surface area and BJH pore volume of porous lactose were reduced to 28.8735 ± 0.3526 m2/g and 0.073315 cc/g, respectively. The reduction rate was based on the quercetin loading efficiency of highly-porous lactose. DSC analysis and XRD analysis suggest that the sediments of quercetin in the nanopores of porous lactose are crystalline. FTIR spectroscopy results suggest that there is no significant interaction between quercetin and lactose. The highly-porous lactose had a higher loading efficiency of 20.3% (w/w) compared to the α-lactose (with 5.2% w/w). The release rates of quercetin from the highly-porous lactose tablets were faster compared to the conventional α-lactose carrier.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 588 ◽  
Author(s):  
Giorgio Gatti ◽  
Mina Errahali ◽  
Lorenzo Tei ◽  
Maurizio Cossi ◽  
Leonardo Marchese

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 °C, and chemical activation with KOH followed by thermal treatment at 750 or 800 °C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 °C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volume—the textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m2/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed.


2012 ◽  
Vol 610-613 ◽  
pp. 1701-1704
Author(s):  
Man Cheng Zhang ◽  
Wei Wang ◽  
Cong Jian Huang ◽  
Ai Min Li

The adsorption behaviors of chlortetracycline on two kinds of granular activated carbons with different BET surface area and average pore width have been studied. The results show that larger BET surface area is beneficial for the adsorption capacity, and wider pore structure can enhance the adsorption rate. Initial solution pH has great effect on the adsorption behavior, and the suitable pH for the effective adsorption is from 4 to 8.


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.


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.


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...


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