Determination of emulsion stability by microwave irradiation

1974 ◽  
Vol 51 (3) ◽  
pp. 110-111 ◽  
Author(s):  
Gary E. Petrowski
LWT ◽  
2020 ◽  
Vol 122 ◽  
pp. 109037 ◽  
Author(s):  
Zeynep Hazal Tekin ◽  
Esra Avci ◽  
Salih Karasu ◽  
Omer Said Toker

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.


1999 ◽  
Vol 15 (11) ◽  
pp. 1129-1132 ◽  
Author(s):  
Hui ZHAO ◽  
Yanqiao XIANG ◽  
Xingguo CHEN ◽  
Zhide HU ◽  
Xing-Zheng WU ◽  
...  

2012 ◽  
Vol 554-556 ◽  
pp. 1933-1937 ◽  
Author(s):  
Qing Hua Feng ◽  
Qing Hua Tang ◽  
Wei Lu Zhang ◽  
Yan Hua Jia ◽  
Dong Zhang

A series of catalysis hydrolytic depolymerization of PET catalyzed by zinc acetate, zinc sulfate, stannous oxide respectively under microwave irradiation at different temperature with time was studied, in which the microwave power was 260W, the ratio of water to PET was 10:1 and the dosage of the catalysts was 0.5% of PET. The relative number average molecular weight of the undepolymerized PET was determined by end-group method. The results show that the molecular weight of the undepolymerized PET decreases with the reaction time increasing, and tends to be stable at the end of the depolymerization reaction. Under the same time, the temperature is higher, the molecular weight is smaller. The molecular weight of the undepolymerized PET reduces most quickly with stannous oxide among the three catalysts.


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