Design and Synthesis of Nanostructured Porous SnO2with High Surface Areas and Their Optical and Dielectric Properties

2008 ◽  
Vol 112 (23) ◽  
pp. 8668-8674 ◽  
Author(s):  
Debraj Chandra ◽  
Nillohit Mukherjee ◽  
Anup Mondal ◽  
Asim Bhaumik
Keyword(s):  
Dielectric Properties ◽  
High Surface ◽  
Design And Synthesis ◽  
Surface Areas

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 A simple one-step electrochemical deposition of bioinspired nanocomposite for the non-enzymatic detection of dopamine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vijayaraj Kathiresan ◽  
Dinakaran Thirumalai ◽  
Thenmozhi Rajarathinam ◽  
Miri Yeom ◽  
Jaewon Lee ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electrochemical Characteristics ◽  
Surface Areas ◽  
Electrochemically Reduced Graphene Oxide ◽  
Sensitivity And Selectivity ◽  
Controlled Deposition ◽  
Enzymatic Detection ◽  
Walled Carbon Nanotubes

AbstractA simple and cost-effective electrochemical synthesis of carbon-based nanomaterials for electrochemical biosensor is of great challenge these days. Our study describes a single-step electrochemical deposition strategy to prepare a nanocomposite of electrochemically reduced graphene oxide (ErGO), multi-walled carbon nanotubes (MWCNTs), and polypyrrole (PPy) in an aqueous solution of pH 7.0 for dopamine (DA) detection. The ErGO/MWCNTs/PPy nanocomposites show enhanced electrochemical performance due to the strong π–π* stacking interactions among ErGO, MWCNTs, and PPy. The efficient interaction of the nanocomposites is confirmed by evaluating its physical and electrochemical characteristics using field-emission scanning electron microscopy, Raman spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The deposited nanocomposites are highly stable on the substrates and possess high surface areas, which is vital to improve the sensitivity and selectivity for DA detection. The controlled deposition of the ErGO/MWCNTs/PPy nanocomposites can provide enhanced electrochemical detection of DA. The sensor demonstrates a short time response within 2 s and is a highly sensitive approach for DA detection with a dynamic linear range of 25–1000 nM (R2 = 0.999). The detection limit is estimated to be 2.3 nM, and the sensor sensitivity is calculated to be 8.96 μA μM−1 cm−2, with no distinct responses observed for other biological molecules.

A facile method to fabricate monolithic alumina–silica aerogels with high surface areas and good mechanical properties

2020 ◽  
Vol 40 (6) ◽  
pp. 2480-2488 ◽  
Author(s):  
Fei Peng ◽  
Yonggang Jiang ◽  
Junzong Feng ◽  
Liangjun Li ◽  
Huafei Cai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Surface ◽  
Silica Aerogels ◽  
Surface Areas ◽  
Monolithic Alumina

Evaluation of a Porous Imine-Based Covalent Organic Framework for Solid-Phase Extraction of Nitroimidazoles

2022 ◽  
Author(s):  
zhikai hong ◽  
yingjiao dong ◽  
ruijie wang ◽  
Guanhua Wang
Keyword(s):  
Thermal Stability ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
High Surface ◽  
Sample Pretreatment ◽  
Phase Extraction ◽  
Covalent Organic Framework ◽  
Framework Materials ◽  
Surface Areas ◽  
Organic Framework

Covalent organic framework materials (COFs), a kind of porous organic material, have excellent potential application in the field of sample pretreatment due to their high surface areas and thermal stability....

scholarly journals The Effects of Methane Storage Capacity Using Upgraded Activated Carbon by KOH

2018 ◽  
Vol 8 (9) ◽  
pp. 1596 ◽  
Author(s):  
Jung Park ◽  
Gi Lee ◽  
Sang Hwang ◽  
Ji Kim ◽  
Bum Hong ◽  
...  
Keyword(s):  
Surface Area ◽  
Storage Capacity ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Surface ◽  
Heat Of Adsorption ◽  
Low Grade ◽  
Surface Areas ◽  
Ch4 Adsorption ◽  
Ch4 Storage

In this study, a feasible experiment on adsorbed natural gas (ANG) was performed using activated carbons (ACs) with high surface areas. Upgraded ACs were prepared using chemical activation with potassium hydroxide, and were then applied as adsorbents for methane (CH4) storage. This study had three principal objectives: (i) upgrade ACs with high surface areas; (ii) evaluate the factors regulating CH4 adsorption capacity; and (iii) assess discharge conditions for the delivery of CH4. The results showed that upgraded ACs with surface areas of 3052 m2/g had the highest CH4 storage capacity (0.32 g-CH4/g-ACs at 3.5 MPa), which was over two times higher than the surface area and storage capacity of low-grade ACs (surface area = 1152 m2/g, 0.10 g-CH4/g-ACs). Among the factors such as surface area, packing density, and heat of adsorption in the ANG system, the heat of adsorption played an important role in controlling CH4 adsorption. The released heat also affected the CH4 storage and enhanced available applications. During the discharge of gas from the ANG system, the residual amount of CH4 increased as the temperature decreased. The amount of delivered gas was confirmed using different evacuation flow rates at 0.4 MPa, and the highest efficiency of delivery was 98% at 0.1 L/min. The results of this research strongly suggested that the heat of adsorption should be controlled by both recharging and discharging processes to prevent rapid temperature change in the adsorbent bed.

Robust transparent mesoporous silica membranes as matrices for colorimetric sensors

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16549-16553 ◽  
Author(s):  
Donghun Kim ◽  
Bradley F. Chmelka
Keyword(s):  
Heavy Metal ◽  
Mesoporous Silica ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Colorimetric Detection ◽  
High Surface ◽  
Silica Membranes ◽  
Surface Areas ◽  
Functionalized Mesoporous Silica ◽  
Colorimetric Sensors

Transparent functionalized mesoporous silica membranes have been prepared with high surface areas (∼500 m2 g−1) that exhibit high sensitivities for colorimetric detection and sensing of dilute heavy-metal ions (e.g., Pb2+).

scholarly journals Synthesis and Optimization of Chitosan Nanoparticles Loaded with L-Ascorbic Acid and Thymoquinone

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 920 ◽  
Author(s):  
Nurhanisah Othman ◽  
Mas Masarudin ◽  
Cha Kuen ◽  
Nurul Dasuan ◽  
Luqman Abdullah ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ascorbic Acid ◽  
Infrared Spectroscopy ◽  
Encapsulation Efficiency ◽  
High Surface ◽  
Chitosan Nanoparticles ◽  
Polydispersity Index ◽  
Ionic Gelation ◽  
Surface Areas ◽  
Efficient Delivery

The combination of compounds with different classes (hydrophobic and hydrophilic characters) in single chitosan carrier is a challenge due to the hydrophilicity of chitosan. Utilization of l-ascorbic acid (LAA) and thymoquinone (TQ) compounds as effective antioxidants is marred by poor bioavailability and uptake. Nanoparticles (NPs) solved the problem by functioning as a carrier for them because they have high surface areas for more efficient delivery and uptake by cells. This research, therefore, synthesized chitosan NPs (CNPs) containing LAA and TQ, CNP-LAA-TQ via ionic gelation routes as the preparation is non-toxic. They were characterized using electron microscopy, zetasizer, UV–VIS spectrophotometry, and infrared spectroscopy. The optimum CNP-LAA-TQ size produced was 141.5 ± 7.8 nm, with a polydispersity index (PDI) of 0.207 ± 0.013. The encapsulation efficiency of CNP-LAA-TQ was 22.8 ± 3.2% for LAA and 35.6 ± 3.6% for TQ. Combined hydrophilic LAA and hydrophobic TQ proved that a myriad of highly efficacious compounds with poor systemic uptake could be encapsulated together in NP systems to increase their pharmaceutical efficiency, indirectly contributing to the advancement of medical and pharmaceutical sectors.

scholarly journals Preparation of Versatile, Porous Poly-Arylthioethers by Reversible Pd-Catalysed C–S/C–S Metathesis

2021 ◽  
Author(s):  
Miguel A. Rivero-Crespo ◽  
Georgios Toupalas ◽  
Bill Morandi
Keyword(s):  
High Surface ◽  
Building Blocks ◽  
Polyphenylene Sulfide ◽  
Extreme Resistance ◽  
Surface Areas ◽  
Metal Capture ◽  
2D And 3D ◽  
Metal Sensing ◽  
Single Material ◽  
Porous Poly

Porous organic frameworks have shown a number of promising properties; however, their industrial application is usually hampered due to the lability of their linkages (imine, boroxine, etc.). Inspired by the outstanding chemical, mechanical and thermal resistance of the 1D polymer polyphenylene sulfide (PPS), we hypothesized that 2D and 3D poly-arylthioether frameworks would merge the attractive features common to porous frameworks and PPS in a single material. Herein, we report a Pd-catalysed C–S/C–S metathesis-based method to prepare new porous poly-arylthioether frameworks in good yields. The self-correcting nature of the process has enabled the synthesis of new, robust materials with high surface areas. Despite the frameworks’ extreme resistance to harsh chemicals, they can be fully recycled to recover the original building blocks using the same catalytic reaction. In addition, we demonstrate preliminary results showing that these materials have great potential in several environmentally relevant applications including metal capture, metal sensing and heterogeneous catalysis. In a broader context, these results clearly demonstrate the untapped potential of emerging single-bond metathesis reactions in the preparation of new materials.

Sign in / Sign up

Export Citation Format

Share Document