Copper uptake by silica and iron oxide under high surface coverage conditions: surface charge and sorption equilibrium modeling

2003 ◽  
Vol 268 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Kavitha Subramaniam ◽  
Viriya Vithayaveroj ◽  
Sotira Yiacoumi ◽  
Costas Tsouris
Nanoscale ◽  
2017 ◽  
Vol 9 (27) ◽  
pp. 9668-9675 ◽  
Author(s):  
Jia Jia Shao ◽  
Wei Tang ◽  
Tao Jiang ◽  
Xiang Yu Chen ◽  
Liang Xu ◽  
...  

A multi-dielectric-layered vertical contact-separation mode TENG through a corona discharge approach results in outstanding output performances, i.e., a high surface charge density of 283 μC m−2 and excellent cycling stability (92.6% retention after 200 000 cycles).


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
S. Ghiamkazemi ◽  
A. Amanzadeh ◽  
R. Dinarvand ◽  
M. Rafiee-Tehrani ◽  
M. Amini

In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI) is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer “PEG-g-PEI” was synthesized. To target cancer liver cells, two targeting ligands folic acid and galactose (lactobionic acid) which are over expressed on human hepatocyte carcinoma were attached to graft copolymer and “FOL-PEG-g-PEI-GAL” copolymer was synthesized. Composition of this grafted copolymer was characterized using1H-NMR and FTIR spectra. The molecular weight and zeta potential of this copolymer was compared to PEI. The particle size and zeta potential of FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratio were measured using dynamic light scattering (DLS). Cytotoxicity of the copolymer was also studied in cultured HepG2 human hepatoblastoma cell line. The FOL-PEG-g-PEI-GAL/DNA complexes at various N/P ratios exhibited no cytotoxicity in HepG2 cell line compared to PEI 25K as a control. The novel copolymer showed enhanced biodegradability in physiological conditions in compared with PEI and targeted cultured HepG2 cells. More importantly, significant transfection efficiency was exhibited in cancer liver cells. Together, our results showed that “FOL-PEG-g-PEI-GAL” nanoparticals could be considered as a useful non-viral vector for targeted gene delivery.


Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1460
Author(s):  
Myung Gi Ji ◽  
Mohammed Bazroun ◽  
In Ho Cho ◽  
W. Dennis Slafer ◽  
Rana Biswas ◽  
...  

Replica molding-based triboelectrification has emerged as a new and facile technique to generate nanopatterned tribocharge on elastomer surfaces. The “mechano-triboelectric charging model” has been developed to explain the mechanism of the charge formation and patterning process. However, this model has not been validated to cover the full variety of nanotexture shapes. Moreover, the experimental estimation of the tribocharge’s surface density is still challenging due to the thick and insulating nature of the elastomeric substrate. In this work, we perform experiments in combination with numerical analysis to complete the mechano-triboelectrification charging model. By utilizing Kelvin probe force microscopy (KPFM) and finite element analysis, we reveal that the mechano-triboelectric charging model works for replica molding of both recessed and protruding nanotextures. In addition, by combining KPFM with numerical electrostatic modeling, we improve the accuracy of the surface charge density estimation and cross-calibrate the result against that of electrostatic force microscopy. Overall, the regions which underwent strong interfacial friction during the replica molding exhibited high surface potential and charge density, while those suffering from weak interfacial friction exhibited low values on both. These multi-physical approaches provide useful and important tools for comprehensive analysis of triboelectrification and generation of nanopatterned tribocharge. The results will widen our fundamental understanding of nanoscale triboelectricity and advance the nanopatterned charge generation process for future applications.


Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3848 ◽  
Author(s):  
Ami Hannon ◽  
Jing Li

Detection of carbon dioxide (CO2) is very important for environmental, health, safety and space applications. We have studied novel multiwall carbon nanotubes (MWCNTs) and an iron oxide (Fe2O3) nanocomposite based chemiresistive sensor for detection of CO2 at room temperature. The sensor has been miniaturized to a chip size (1 cm × 2 cm). Good sensing performance was observed with a wide detection range of CO2 concentrations (100–6000 ppm). Structural properties of the sensing materials were characterized using Field-Emission Scanning Electron Microscopy, Fourier-Transform Infrared and Raman spectroscopies. The greatly improved sensitivity of the composite materials to CO2 can be attributed to the formation of a depletion layer at the p-n junction in an MWCNT/iron oxide heterostructure, and new CO2 gas molecules adhere to the high surface area of MWCNTs due to the concentration gradient. The test results showed that the CO2 sensor possesses fast response, compact size, ultra-low power consumption, high sensitivity and wide dynamic detection range.


1972 ◽  
Vol 250 (9) ◽  
pp. 908-909 ◽  
Author(s):  
K. Furusawa ◽  
W. Norde ◽  
J. Lyklema
Keyword(s):  

2018 ◽  
Vol 9 (18) ◽  
pp. 4285-4298 ◽  
Author(s):  
Alicia C. McGeachy ◽  
Emily R. Caudill ◽  
Dongyue Liang ◽  
Qiang Cui ◽  
Joel A. Pedersen ◽  
...  

Quantifying the number of charges on peptides bound to interfaces requires reliable estimates of (i) surface coverage and (ii) surface charge, both of which are notoriously difficult parameters to obtain, especially at solid/water interfaces. Here, we report the thermodynamics and electrostatics governing the interactions of l-lysine and l-arginine octamers (Lys8 and Arg8) with supported lipid bilayers prepared.


RSC Advances ◽  
2020 ◽  
Vol 10 (61) ◽  
pp. 37374-37381
Author(s):  
Santhosh S. Nair ◽  
Jianhong Chen ◽  
Adam Slabon ◽  
Aji P. Mathew

Cellulose nanocrystals (CNCs) are promising building blocks for water purification due to their high surface area, tuneability of surface charge and grafting of surface groups depending on the pollutants.


RSC Advances ◽  
2019 ◽  
Vol 9 (70) ◽  
pp. 41120-41125 ◽  
Author(s):  
Mihye Wu ◽  
Do Youb Kim ◽  
Hyunsoo Park ◽  
Kyeong Min Cho ◽  
Ju Ye Kim ◽  
...  

Mo2CTx supported on carbon nanotube was first applied as a cathode for Li–O2 batteries. The high surface coverage of Mo2CTx resulted in the toroidal Li2O2 formation via solution growth model due to the inaccessibility of O2 to the cathode surface.


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