Effect of cationic and non-ionic surfactants on the microstructure of ambient pressure dried zirconia aerogel

2017 ◽  
Vol 7 (4) ◽  
pp. 291-298 ◽  
Author(s):  
Hae-Noo-Ree Jung ◽  
Wooje Han ◽  
Hyung Hee Cho ◽  
Hyung-Ho Park
Keyword(s):  
Ambient Pressure ◽  
Ionic Surfactants ◽  
Zirconia Aerogel

Environmental microscopy of capillary stress-induced strain behavior in ambient-pressure aerogels

1996 ◽  
Vol 54 ◽  
pp. 850-851
Author(s):  
Sudeep M. Rao ◽  
Joshua Samuel ◽  
Sai S. Prakash ◽  
C. Jeffrey Brinker
Keyword(s):  
Silica Aerogel ◽  
Ambient Pressure ◽  
Drying Shrinkage ◽  
Pore Filling ◽  
Silica Network ◽  
Strain Behavior ◽  
Partially Saturated ◽  
Capillary Stress ◽  
Wetting Liquid ◽  
Aerogel Films

Ambient pressure silica aerogel thin films have recently been prepared by exploiting reversible drying shrinkage caused by derivatization of the internal gel surface. Aerogels have porosities of upto 99.9% and due to the small size of the pores (few nanometers), large capillary stresses are produced in gels that are partially saturated with a wetting liquid. As a result of these capillary stresses, the flexible silica network undergoes strain which has been observed using environmental microscopy. This technique allows variation of the equilibrium vapor pressure and temperature, and a simultaneous monitoring of the deformation of the unconstrained film thickness. We have observed >600% deformation during the pore-filling and pore-emptying cycles. In this presentation, we discuss the unique stress-strain behavior of these films.Ref.: Sai S. Prakash, C. Jeffrey Brinker, Alan J. Hurd & Sudeep M. Rao, "Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage", Nature. Vol. 374, 30 March, 1995, 439-443.

ON MAGNETIC PROPERTIES 0F (TMTSF)2PF6AT AMBIENT PRESSURE

1983 ◽  
Vol 44 (C3) ◽  
pp. C3-1001-C3-1005
Author(s):  
S. Iwabuchi ◽  
H. Fukuyama
Keyword(s):  
Magnetic Properties ◽  
Ambient Pressure

Adsorption of ionic and non-ionic surfactants by wool charring waste

1981 ◽  
Vol 31 (1) ◽  
pp. 395-400 ◽  
Author(s):  
Francis Perineau ◽  
Antoine Gaset
Keyword(s):  
Ionic Surfactants

NEAR-WALL CHARACTERISTICS OF AN IMPINGING GASOLINE SPRAY AT INCREASED AMBIENT PRESSURE AND WALL TEMPERATURE

2009 ◽  
Vol 19 (11) ◽  
pp. 997-1012 ◽  
Author(s):  
Jochen Stratmann ◽  
D. Martin ◽  
P. Unterlechner ◽  
R. Kneer
Keyword(s):  
Wall Temperature ◽  
Ambient Pressure ◽  
Near Wall

Effect of ambient pressure on low-density nozzle plumes

1995 ◽  
Author(s):  
Chan-Hong Chung ◽  
Kenneth D ◽  
Robert Stubbs
Keyword(s):  
Ambient Pressure ◽  
Low Density

Artemisinin (ART) Drug Delivery Using Mixed Non-ionic Surfactants and Evaluation of Their Efficiency in Different Cancer Cell Lines

2017 ◽  
Vol 4 (4) ◽  
Author(s):  
Elnaz Asgharkhani ◽  
Aazam Najmafshar ◽  
Mohsen Chiani
Keyword(s):  
Zeta Potential ◽  
Cell Line ◽  
Mtt Assay ◽  
Therapeutic Index ◽  
Stability Study ◽  
Polydispersity Index ◽  
Ionic Surfactants ◽  
Cytotoxicity Test ◽  
Molar Ratios ◽  
Chemotherapy Agent

This study aims to investigate the effects of different non-ionic surfactants on physicochemical properties of ART niosomes. ART is a natural compound that is used as an antimalarial and chemotherapy agent in medicine. ART has low bioavailability, stability and solubility. In order to solve these problems and enhancing the efficiency of the drug, nanotechnology was used. In the present study, several niosomal formulations of ART prepared using different molar ratios of Span 60 : Tween 60 : PEG-600: ART in PBS. These three formulations were FI (1:1:0.5:0.5), FII (2:1:0.5:0.5) and FIII (1:2:0.5:0.5), respectively. The encapsulation efficiency was measured by HPLC and the drug release was evaluated by dialysis method. The cytotoxicity test was determined by MTT assay. The size, zeta potential and polydispersity index of the vesicles was measured by Zeta Sizer. Stability study was performed within two months. The MTT assay results showed that cytotoxicity effect of these formulations on MCF-7 cell line is better than C6 cell line and the FIII had the best results for both of them. The entrapment efficiencies of the formulations I, II and III were obtained 82.2±1.88%, 75.5±0.92% and 95.5±1.23%, respectively. The results of size, zeta potential and polydispersity index indicated that the size of the vesicles is below 200 nm, their surface charge is about -35 mV and they were monodisperse. Stability and release study indicated that the formulation III has the best stability and release pattern. Therefore, the use of PEGylated niosomal ART can effectively improve its therapeutic index, stability and solubility.

Influence of intramolecular interactions on carbon dioxide gas adsorption capacity in Mesoporous Imine polymers

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Density Functional ◽  
Gas Adsorption ◽  
Ambient Pressure ◽  
Condensation Reaction ◽  
Intramolecular Interactions ◽  
Carbon Dioxide Adsorption ◽  
Nitrogen Gas ◽  
Adsorption Characteristic

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>

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