scholarly journals Metal Nanoparticles Supported on Al-MCM-41 via In Situ Aqueous Synthesis

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Ivonne Alonso-Lemus ◽  
Ysmael Verde-Gomez ◽  
Alfredo Aguilar-Elguézabal ◽  
Lorena Álvarez-Contreras
Keyword(s):  
Metallic Nanoparticles ◽  
High Surface ◽  
Textural Properties ◽  
Active Phase ◽  
Ruthenium Catalysts ◽  
Aqueous Synthesis ◽  
Surface Areas ◽  
Electrochemical Testing ◽  
Size And Morphology ◽  
Mcm 41

MCM-41 have been used to custom synthesize catalysts in because of the controllable properties, such as pore size, active phase incorporation, crystal size, and morphology, among others. In this paper, a simple and versatile method for the incorporation of platinum, ruthenium, and palladium onto Al-MCM-41 mesoporous silica by direct inclusion of various precursors was studied. M/Al-MCM-41 structure, textural properties, morphology, and elemental composition were analyzed. The results obtained indicate that the Al-MCM-41 mesoporous-ordered structure was not affected by metallic particle incorporation. High-surface areas were obtained (1131 m2/g). Metallic nanoparticles dispersion on Al-MCM-41 was homogeneous for all samples and its particles sizes were between 6 nm to 20 nm. Microscopy results show round shape particles in platinum and palladium samples; however, ruthenium catalysts exhibit a spherical and rod shapes. Electrochemical testing for Pt/Al-MCM-41 showed electrocatalytic activity forH2oxidation which indicates that these materials can be used as a catalyst in electrochemical devices.

Fabrication of Mesoporous ZrO2 by Using Rosin-Based Quaternary Ammonium Salt

2011 ◽  
Vol 239-242 ◽  
pp. 3257-3261 ◽  
Author(s):  
Peng Wang ◽  
Zhen Dong Zhao ◽  
Li Zhi He ◽  
Liang Wu Bi ◽  
Yu Xiang Chen
Keyword(s):  
Ammonium Salt ◽  
Significant Influence ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salt ◽  
High Surface ◽  
Textural Properties ◽  
Precipitation Method ◽  
Adsorption And Desorption ◽  
Surface Areas ◽  
Ft Ir

Mesoporous zirconias were prepared by precipitation method using rosin-based quaternary ammonium salt as a directing agent. The samples were characterized by means of XRD, FT-IR and N2-adsorption and desorption measurements. The phase of precursors was amorphous, and well crystallized tetragonal zirconias were obtained after the calcination at 450 °C. The synthesized mesoporous zirconias possessed high surface areas ranging from 183.56 to 203.87 m2g-1and big pore diameters varying from 6.27 to 7.58 nm. The content of the rosin-based quaternary ammonium salt had significant influence on the textural properties of the mesoporous zirconias. Surface areas, pore volumes and pore diameters of the mesoporous zirconias decreased when increasing the surfactant dosage.

scholarly journals Development of Amperometric Laccase Biosensor through Immobilizing Enzyme in Magnesium-Containing Mesoporous Silica Sieve (Mg-MCM-41)/Polyvinyl Alcohol Matrix

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Z. Dai ◽  
M. Q. Guo ◽  
X. J. Wang ◽  
H. F. Wang ◽  
W. Y. Chen
Keyword(s):  
Mesoporous Silica ◽  
High Surface ◽  
Acetate Buffer Solution ◽  
Buffer Solution ◽  
Experimental Conditions ◽  
Surface Areas ◽  
Long Time ◽  
Good Biocompatibility ◽  
Laccase Immobilization ◽  
Mcm 41

Magnesium-containing mesoporous silica sieve (Mg-MCM-41) provided a suitable immobilization of biomolecule matrix due to its uniform pore structure, high surface areas, fast electron-transfer rate, and good biocompatibility. Based on this, an amperometric biosensor was developed by entrapping laccase into the Mg-MCM-41/PVA composite matrix. Laccase from Trametes versicolor was assembled on a composite film of Mg-MCM-41/PVA modified Au electrode and the electrode was investigated by cyclic voltammetry, impedance spectroscopy, and chronoamperometry. The results indicated that the Mg-MCM-41/PVA/Lac modified electrode exhibited excellent catalytic activity towards catechol at room temperature in pH 4.8 acetate buffer solution. The optimum experimental conditions of biosensor for the detection of catechol were studied in detail. Under the optimal conditions, the linear range was from 0.94 to 10.23 μM with the sensitivity of 16.9227 A/M, the detection limit of 0.00531 μM, and the response time of less than 14 s. The Michaelis-Menten constant (KMapp) was estimated by Lineweaver-Burk equation and theKMappvalue was about 1.01 μM. In addition, the biosensor exhibited high reproducibility and long-time stability. This work demonstrated that Mg-MCM-41/PVA composite provides a suitable support for laccase immobilization and construction of biosensor.

scholarly journals One-Pot Cu/TiO2 Nanoparticles Synthesis for Trans-Ferulic Acid Conversion into Vanillin

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3985 ◽  
Author(s):  
Paulette Gómez-López ◽  
Noelia Lázaro ◽  
Clemente G. Alvarado-Beltrán ◽  
Antonio Pineda ◽  
Alina M. Balu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ferulic Acid ◽  
Metallic Nanoparticles ◽  
High Surface ◽  
Hydrothermal Process ◽  
Atomic Ratio ◽  
Homogeneous Distribution ◽  
One Pot ◽  
Surface Areas ◽  
Cost Efficient

In this study, the co-synthesis of TiO2 and Cu metallic nanoparticles obtained via one-pot cost-efficient hydrothermal process has been addressed. Different nanocatalysts with Cu contents were characterized by X-ray diffraction, nitrogen porosimetry, scanning electron microscopy, and transmission electron microscopy. The TiO2 and Cu metallic nanoparticles were synthesized with copper loading up to one (Cu/Ti atomic ratio). Synthesized catalysts exhibited pore sizes in the mesoporous range and high surface areas above 150 m2/g. The particle size for TiO2 presented a homogeneous distribution of approximately 8 nm, moreover, Cu nanoparticles varied from 12 to >100 nm depending on the metal loading. The nanostructured materials were successfully tested in the conversion of trans-ferulic acid into vanillin under sustainable conditions, achieving the best performance for 0.3 Cu/Ti atomic ratio (70% vanillin yield).

Synthesis Optimization of Mesoporous MCM-41 Materials in Acidic Media

1996 ◽  
Vol 454 ◽  
Author(s):  
A. Karlsson ◽  
R. Schmidt ◽  
M. Stocker
Keyword(s):  
Low Cost ◽  
High Surface ◽  
Point Of View ◽  
High Yield ◽  
Acid Mixture ◽  
Synthesis Time ◽  
Surface Areas ◽  
Short Synthesis ◽  
Enhanced Adsorption ◽  
Mcm 41

ABSTRACTThe synthesis of MCM-41 in a highly acidic medium has been optimised. It was found that the relatively low-cost synthesis gave a material with extremely high surface areas (more than 1500 m2/g) compared to that obtained in conventional alkaline synthesis (ca 1100 m2/g). Judged by the short synthesis time, high yield, enhanced adsorption capacity, large particle size and thermal stability, the acid route to MCM-41 appears promising from an industrial point of view. Additional cost-reducing steps, such as the recycling of the “acid matrix” and the reduction of the volume of the water/acid mixture were successfully applied.

Nanotechnology, a tool for diagnostics and treatment of cancer

2021 ◽  
Vol 21 ◽  
Author(s):  
Abdul Nasir ◽  
Amir Khan ◽  
Jiayi Li ◽  
Muhammad Naeem ◽  
Atif Ali Khan Khalil ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Cancer Cells ◽  
Metallic Nanoparticles ◽  
Polymeric Nanoparticles ◽  
High Surface ◽  
Cancer Diagnostics ◽  
Biological Molecules ◽  
Synthesis Of Nanoparticles ◽  
Cancerous Cell ◽  
Size And Morphology

: Nanotechnology has shown promising advancements in the field of drug development and its delivery. In particular, the applications of nanoparticles for treatment and diagnostics of cancer reached such a precision that it can detect a single cancer cell and can target it to deliver a payload for the treatment of that cancerous cell. Conventional cancer therapy methods have side effects, and diagnostics techniques are time-consuming and expensive. Nanoparticles (NPs) such as polymeric nanoparticles (nanogels, nanofibers, liposomes), metallic nanoparticles such as gold NP (GNPs), sliver NP (AgNP), calcium nanoparticles (CaNPs), carbon nanotubes (CNTs), graphene, and quantum dots (QDs) have revolutionized cancer diagnostics and treatments due to their high surface charge, size and morphology. Functionalization of these nanoparticles with different biological molecules, such as antibodies, helps them to targeted the delivery and early detection of cancer cells through their plasmon resonance properties. While some of the magnetic properties of nanoparticles such as iron (Fe), copper (Cu), and carbon NT were also evaluated for detection and treatments of cancer cells. An advanced type of nanoparticles, such as nanobubbles and oxygen-releasing polymers, are helping to address the hypoxia conditions in the cancer microenvironment, while others are employed in photodynamic therapy (PDT) and photothermal therapy (PTT) due to their intrinsic theranostic properties. The green synthesis of nanoparticles has further increased biocompatibility and broadened their applications. In this review paper, we discussed the advancement in nanotechnology and its applications for cancer treatment and diagnostics and highlighted challenges for translation of these advanced nano-based techniques for clinical applications and their green synthesis.

scholarly journals Aminopropyl Functionalised MCM-41: Synthesis and Application for Adsorption of Pb(II) and Cd(II)

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Pham Dinh Du ◽  
Nguyen Trung Hieu ◽  
Thuy Chau To ◽  
Long Giang Bach ◽  
Mai Xuan Tinh ◽  
...  
Keyword(s):  
Indirect Method ◽  
Direct Method ◽  
Error Function ◽  
High Surface ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Surface Areas ◽  
Paired Samples ◽  
Adsorption Desorption ◽  
Mcm 41

This paper shows a comparison of porous properties of aminopropyl-MCM-41 materials functionalised via the direct and indirect methods. The obtained materials were characterised using X-ray powder diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), adsorption/desorption isotherms of nitrogen, and Fourier-transfer infrared (FT-IR) spectroscopy. The results showed that the direct method provided the aminopropyl-MCM-41 material with well-ordered pores and high surface areas but with a lower quantity of grafted 3-aminopropyltriethoxysilane than the indirect method. To remove the organic template in the indirect method, solvent extraction with HCl/C2H5OH and calcination at 500°C were used, and the former gave a higher quantity of grafted 3-aminopropyltriethoxysilane in the resulting aminopropyl-MCM-41 materials. The experimental data were applied to the isotherm models of adsorption including Langmuir, Freundlich, Redlich–Peterson, and Sips either in the linear or nonlinear form. In order to avoid the bias of the determination coefficient and the error function method, the paired-samples t-test as an alternative method was first proposed to look for the most appropriate adsorption isotherms. The maximum adsorption capacity of Cd(II) and Pb(II) was 14.08 mg·g−1 and 64.21 mg·g−1, respectively. The mechanism of complexation and isoelectric interaction was suggested to explain the adsorption of Pb(II) and Cd(II) from aqueous solutions on aminopropyl functionalised MCM-41 in the range of pH from 2 to 9.

A Highly Crystalline Anthracene-Based MOF-74 Series Featuring Electrical Conductivity and Luminescence

2019 ◽  
Author(s):  
Patricia Scheurle ◽  
Andre Mähringer ◽  
Andreas Jakowetz ◽  
Pouya Hosseini ◽  
Alexander Richter ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Metal Ions ◽  
Light Emission ◽  
Block Design ◽  
High Surface ◽  
Visible Spectrum ◽  
Building Blocks ◽  
Divalent Metal Ions ◽  
Conductivity Enhancement ◽  
Surface Areas

Recently, a small group of metal-organic frameworks (MOFs) has been discovered featuring substantial charge transport properties and electrical conductivity, hence promising to broaden the scope of potential MOF applications in fields such as batteries, fuel cells and supercapacitors. In combination with light emission, electroactive MOFs are intriguing candidates for chemical sensing and optoelectronic applications. Here, we incorporated anthracene-based building blocks into the MOF-74 topology with five different divalent metal ions, that is, Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, resulting in a series of highly crystalline MOFs, coined ANMOF-74(M). This series of MOFs features substantial photoluminescence, with ANMOF-74(Zn) emitting across the whole visible spectrum. The materials moreover combine this photoluminescence with high surface areas and electrical conductivity. Compared to the original MOF-74 materials constructed from 2,5-dihydroxy terephthalic acid and the same metal ions Zn2+, Mg2+, Ni2+, Co2+ and Mn2+, we observed a conductivity enhancement of up to six orders of magnitude. Our results point towards the importance of building block design and the careful choice of the embedded MOF topology for obtaining materials with desired properties such as photoluminescence and electrical conductivity.

scholarly journals Mitigating the Agglomeration of Nanofiller in a Mixed Matrix Membrane by Incorporating an Interface Agent

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 328
Author(s):  
Manh-Tuan Vu ◽  
Gloria M. Monsalve-Bravo ◽  
Rijia Lin ◽  
Mengran Li ◽  
Suresh K. Bhatia ◽  
...  
Keyword(s):  
Gas Separation ◽  
Polymer Matrix ◽  
Ion Beam ◽  
High Surface ◽  
Mixed Matrix Membrane ◽  
Mechanical And Thermal Properties ◽  
Separation Membranes ◽  
Surface Areas ◽  
Separation Membrane ◽  
Focus Ion Beam

Nanodiamonds (ND) have recently emerged as excellent candidates for various applications including membrane technology due to their nanoscale size, non-toxic nature, excellent mechanical and thermal properties, high surface areas and tuneable surface structures with functional groups. However, their non-porous structure and strong tendency to aggregate are hindering their potential in gas separation membrane applications. To overcome those issues, this study proposes an efficient approach by decorating the ND surface with polyethyleneimine (PEI) before embedding it into the polymer matrix to fabricate MMMs for CO2/N2 separation. Acting as both interfacial binder and gas carrier agent, the PEI layer enhances the polymer/filler interfacial interaction, minimising the agglomeration of ND in the polymer matrix, which is evidenced by the focus ion beam scanning electron microscopy (FIB-SEM). The incorporation of PEI into the membrane matrix effectively improves the CO2/N2 selectivity compared to the pristine polymer membranes. The improvement in CO2/N2 selectivity is also modelled by calculating the interfacial permeabilities with the Felske model using the gas permeabilities in the MMM. This study proposes a simple and effective modification method to address both the interface and gas selectivity in the application of nanoscale and non-porous fillers in gas separation membranes.

scholarly journals Silica Monolith for the Removal of Pollutants from Gas and Aqueous Phases

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1316
Author(s):  
Vanessa Miglio ◽  
Chiara Zaccone ◽  
Chiara Vittoni ◽  
Ilaria Braschi ◽  
Enrico Buscaroli ◽  
...  
Keyword(s):  
Rhodamine B ◽  
Water Solution ◽  
Synthesis Method ◽  
Textural Properties ◽  
Adsorption Properties ◽  
Water Soluble ◽  
Silica Monoliths ◽  
Physico Chemical ◽  
Gaseous Toluene ◽  
Mcm 41

This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.

scholarly journals Coal Fly Ash Derived Silica Nanomaterial for MMMs—Application in CO2/CH4 Separation

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 78
Author(s):  
Marius Gheorghe Miricioiu ◽  
Violeta-Carolina Niculescu ◽  
Constantin Filote ◽  
Maria Simona Raboaca ◽  
Gheorghe Nechifor
Keyword(s):  
Fly Ash ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Coal Fly Ash ◽  
High Surface ◽  
Industrial Applications ◽  
Mixed Matrix Membranes ◽  
Co2 Removal ◽  
Mcm 41

In order to obtained high selective membrane for industrial applications (such as natural gas purification), mixed matrix membranes (MMMs) were developed based on polysulfone as matrix and MCM-41-type silica material (obtained from coal fly ash) as filler. As a consequence, various quantities of filler were used to determine the membranes efficiency on CO2/CH4 separation. The coal fly ash derived silica nanomaterial and the membranes were characterized in terms of thermal stability, homogeneity, and pore size distribution. There were observed similar properties of the obtained nanomaterial with a typical MCM-41 (obtained from commercial silicates), such as high surface area and pore size distribution. The permeability tests highlighted that the synthesized membranes can be applicable for CO2 removal from CH4, due to unnoticeable differences between real and ideal selectivity. Additionally, the membranes showed high resistance to CO2 plasticization, due to permeability decrease even at high feed pressure, up to 16 bar.

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