Thermodynamics of micellisation and gelation of oxyethylene/oxypropylene diblock copolymers in aqueous solution studied by light scattering and differential scanning calorimetry

1992 ◽  
Vol 88 (10) ◽  
pp. 1441 ◽  
Author(s):  
Yulin Deng ◽  
Ga-Er Yu ◽  
Colin Price ◽  
Colin Booth
1998 ◽  
Vol 23 (0) ◽  
pp. 09-16
Author(s):  
Marco Aurélio da Silva CARVALHO FILHO ◽  
Massao IONASHIRO

Compounds of cinnamic acid with manganese, zinc and lead have been prepared in aqueous solution. Thermogravimetry, derivative thermogravimetry (TG, DTG), differential scanning calorimetry (DSC), X-ray diffraction and complexometry have been used in the characterization as well as in the study of the thermal stability and interpretation concerning the thermal decomposition.


2010 ◽  
Vol 14 (03) ◽  
pp. 278-283 ◽  
Author(s):  
Virginia E. Diz ◽  
Gabriela A. Gauna ◽  
Cristian A. Strassert ◽  
Josefina Awruch ◽  
Lelia E. Dicelio

Lipophilic substituted zinc(II) phthalocyanines: 2,3,9,10,16,17,23,24-octakis[(N,N-dimethylaminoethylsulfanyl)]phthalocyaninatozinc(II) (S1) and tetrakis(N,N-dibutylaminoethoxy)phthalocyaninatozinc(II) (3) were incorporated into soybean L-α-phosphatidylcholine (SPC) liposomes of 100 nm diameter. Liposomes were characterized by static light scattering (SLS), transmission electronic microscopy (TEM), and differential scanning calorimetry. The fluorescence quantum yield and singlet molecular oxygen production of 3 are Φ F = 0.15 and ΦΔ = 0.24, respectively, whereas the same photophysical parameters for S1 are Φ F = 0.13 and ΦΔ = 0.51. Higher values of Φ F and ΦΔ are obtained in organic solvent for both dyes. Synthesis of compound 3 has also been reported.


Author(s):  
C S Velez-Saboyá ◽  
J R Guzmán-Sepúlveda ◽  
Jesus Carlos Ruiz-Suárez

Abstract Phase transitions of liposomes are normally studied by differential scanning calorimetry (DSC). A suspension of liposomes is subjected to an increase (decrease) of temperature and when heat is absorbed (released), the liposomes transit from a gel (liquid) to a liquid (gel) phase. This endothermic (exothermic) process takes place at a temperature called the melting temperature Tm, which is distinctive of the type of lipids forming the vesicles. The vesicles, though, also modify their size in the transition. Indeed, the thickness of the membranes decreases (increases) because carbon tails misalign (align). Concomitant with the modifications in the membrane thickness, the diameter (D) of the liposomes changes too. Therefore, when they are inspected by light, the scattered signal carries information from such dilatation (contraction) process. We performed careful experiments using dynamic light scattering (DLS) as a function of temperature to detect the size changes of different liposomes. Gaussian fits of the derivatives of the D vs T curves coincide within 1% with thermograms, which hints to the possibility of performing thermodynamic studies of lipid systems employing light.


2013 ◽  
Vol 721 ◽  
pp. 625-628
Author(s):  
Yuan Yan Yu

This work describes the aqueous-solution technique preparation and characterization of the complex between human-like collagen and copper (II). Pure human-like collagen and the copper complex were characterized by thermo gravimetric (TG) and differential scanning calorimetry (DSC) analysis. The TG curves and DSC data reveal the significant thermal differences between pure protein and the copper complex, demonstrating the formation of a new chemical compound, which is different from the free HLC and with more stable thermodynamic properties.


Langmuir ◽  
1999 ◽  
Vol 15 (15) ◽  
pp. 4975-4980 ◽  
Author(s):  
Laura Cantú ◽  
Mario Corti ◽  
Elena Del Favero ◽  
Elke Muller ◽  
Antonio Raudino ◽  
...  

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