Determination of coalescence stability of emulsions by analytical ultracentrifugation under separation of dispersed phase

Author(s):  
K. Strenge ◽  
A. Seifert
ChemPhysChem ◽  
2008 ◽  
Vol 9 (6) ◽  
pp. 882-890 ◽  
Author(s):  
Miles G. Page ◽  
Thomas Zemb ◽  
Monique Dubois ◽  
Helmut Cölfen

Author(s):  
A Kleitz ◽  
J M Dorey

This paper is devoted to the measuring methods and instrumentation used in the wet-steam area for both aerodynamics measurements (pressure, temperature and velocity) taking into account the interaction between the vapour and the liquid phase, and the characterization of the liquid phase itself (dispersed phase and liquid film). The development of suitable instrumentation is an important part in understanding the formation and evolution of the liquid phase but is now more and more oriented towards practical industrial concerns, such as the direct determination of turbine performance by measuring exhaust wetness or chemical measurements relating to erosion in the transition zone inside the turbine. Emphasis has been given to techniques suitable for use in actual turbines.


2002 ◽  
Vol 3 (1) ◽  
Author(s):  
S. M. W. ZANIN ◽  
M. D. MIGUEL ◽  
M. C. CHIMELLI ◽  
A. B. OLIVEIRA

A estabilidade das emulsões depende intrìnsecamente da interação interfásica estabelecida pelo agente emulsivo, composto anfifílico, entre as fases imiscíveis que as constituem. A escolha, proporção e a característica do tensoativo a ser utilizado na preparação da emulsão almejada, são previstas pormeio da verificação dos valores de equilíbrio hidrófilo-lipófilo (EHL) das substâncias envolvidas, o que permite predizer o tipo de comportamento esperado do composto frente a substâncias polares ou apolares. Os tensoativos devem apresentar valor de EHL equivalente ao da fase dispersa, para poder mantê-la estabilizada frente à fase dispersante. Para determinar o valor de EHL pode-se recorrer a dados em literatura ou equações baseadas na fórmula molecular do composto. Entretanto, quando o EHL de uma substância específica é desconhecido ou a literatura cita em ampla faixa de valor, torna-se útil ensaiar o preparo de emulsões com o óleo cujo EHL deve ser determinado, utilizando-se de tensoativos de EHL conhecidos. Com a notificação do EHL do óleo, pode-se lançar mão de emulgentes ideais com mesmo valor de EHL. HYDROPHILE-LIPOPHILE BALANCE (HLB) DETERMINATION OF VEGETABLE OIL FAMILY Abstract Emulsion stability depends of interface interaction established by emulsifiers, anfiphilic compounds that adsorb between immiscible phases that formemulsion.Choosing, quantifying and characterizing surfactant to be used at desired emulsion preparation are provided through verifying hydrophilelipophile balance (HLB) which allows to predict compound expected behavior opposite polar and nonpolar substances. Surfactants must present HLB value equal to dispersed phase to stabilize it opposite continuous phase. Estimating HLB value can work about literature data resort, calculation which gives HLB from compound molecular formula definition. However, when specific substance’s HLB is unknown, essaying oil whose HLB must be determined emulsion preparation taking known HLB emulsifiers is useful. Getting oil HLB permits using ideal emulsifiers with same HLB value.


1989 ◽  
Vol 171 ◽  
Author(s):  
Frank C. Wilson

ABSTRACTA method for determining particle diameters up to ca 500 rnm is described. X-ray data are obtained with an ultra-high resolution Bonse-Hart diffractometer and subsequently desmeared. The resultant data, viewed as the invariant argument h l(h), are interpreted as arising from a log-normal distribution of independent spherical particles. The distribution is characterized by its median value and breadth.


1972 ◽  
Vol 18 (12) ◽  
pp. 1463-1467 ◽  
Author(s):  
Gerald S Berenson ◽  
S R Srinivasan ◽  
P S Pargaonkar ◽  
B Radhakrishnamurthy ◽  
Edward R Dalferes

Abstract A simplified primary screening procedure is described for determining serum β- plus pre-β-lipoproteins, which is more rapid and less expensive than cholesterol or triglyceride determinations. This method is based on the ability of β- and pre-β-lipoproteins to form insoluble complexes with heparin in presence of Ca2+. Comparison with analytical ultracentrifugation indicated the accuracy of concentrations determined by the present method. This method was used to screen a group of healthy adults and children and diabetic patients. The results show that measuring serum β- plus pre-β-lipoprotein concentrations may be more useful for screening and detecting subtle abnormalities than is determination of either cholesterol or triglyceride.


2017 ◽  
Vol 2 (5) ◽  
pp. 253-260 ◽  
Author(s):  
T. Thajudeen ◽  
J. Walter ◽  
R. Srikantharajah ◽  
C. Lübbert ◽  
W. Peukert

Combination of analytical ultracentrifugation and scanning mobility particle sizer to predict average length and diameter of nanorods in a sample.


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