Giorgio Cerichelli | University of L'Aquila (original) (raw)
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Papers by Giorgio Cerichelli
Colloids and Surfaces B-biointerfaces, 2011
The aggregation properties of a new sultaine surfactant have been studied in buffered aqueous sol... more The aggregation properties of a new sultaine surfactant have been studied in buffered aqueous solution at pH 7.4 under controlled condition of osmolarity.Spontaneously formed sultaine vesicles with a mean diameter of about 1 μm can be observed by optical microscopy. The phase behaviour of the surfactant has been investigated by differential scanning calorimetry (DSC) and Nile Red fluorescence.Two critical vesicular concentrations (CVC1 and CVC2) have been fluorimetrically measured, by using pyrene and Nile Red as the fluorescent probes. The two populations of vesicles behave differently as a consequence of their size.The stability of extruded large unilamellar vesicles (LUV) formed slightly above the CVC1 has been evaluated in the temperature range 25–75 °C by following the rate of spontaneous release of entrapped 5(6)-carboxyfluorescein (CF). The stability of the same vesicles at 70 °C has also been investigated under osmotic stress obtained by adding NaCl or sucrose to the bulk solution.At a sultaine concentration above the CVC2 LUV tend to associate and form stable larger closely packed aggregates as suggested by Dynamic Laser Light Scattering and rheological measurements.► The investigated sultaine surfactant spontaneously forms vesicles in buffered aqueous solution. ► The existence of two populations of vesicles, formed at two CVC values, has been confirmed by means of different techniques (Fluorescence, Dynamic Laser Light Scattering and Rheometry). ► High temperature causes fusion of the large unilamellar vesicles formed above the first CVC. ► The increase of the sultaine concentration above the second CVC causes the association of the vesicles into larger closely packed aggregates.
Langmuir, 2000
This paper reports about the influence of counterions on the solubilization of benzene in aqueous... more This paper reports about the influence of counterions on the solubilization of benzene in aqueous solutions of cetyltrimethylammonium surfactants (CTAX, X = Br - , Cl - , NO 3 - , CH 3 SO 3 - , and (SO 4 ) 2 - 1/2 , CTAB, CTAC, CTAN, CTAMs, and CTAS, respectively) investigated ...
The Journal of Physical Chemistry, 1990
J Am Chem Soc, 1979
ABSTRACT
Journal of the Chemical Society Chemical Communications, 1985
Journal of Chemical Research Synopses, 1988
Journal of the American Chemical Society
ABSTRACT
Langmuir
Cyclization of 2-((3-halopropyl)oxy)phenoxide ion (halo = Br, I; PhBr7 and PhI7, respectively) in... more Cyclization of 2-((3-halopropyl)oxy)phenoxide ion (halo = Br, I; PhBr7 and PhI7, respectively) in micelles is a model for S N 2 reactions of nucleophilic anions at micelle−water interfaces. Sulfobetaine micelles of dodecyldimethylammoniopropanesulfonate (C 12 H 25 N + (CH 3 ) 2 (CH 2 ) 3 ...
Langmuir
The phase diagram of the system composed of H 2 O and tributylhexadecylphosphonium bromide (CTBPB... more The phase diagram of the system composed of H 2 O and tributylhexadecylphosphonium bromide (CTBPBr) has been investigated and the phase boundaries determined. CTBPBr solutions undergo critical demixing phenomena and separate into two fluid phases at temperatures close to ...
The Journal of Physical Chemistry, 1989
Conclusions The surface active sites of V2O5 catalyst under the promoting effect of MOO, were elu... more Conclusions The surface active sites of V2O5 catalyst under the promoting effect of MOO, were elucidated as follows. 1. The surface concentration of redox sites is increased by addition of MOO, to V205 catalysts. The surface V=O species are newly formed on the various crystal ...
Journal of Mining and Metallurgy, Section B: Metallurgy, 2009
Colloids and Surfaces B-biointerfaces, 2011
The aggregation properties of a new sultaine surfactant have been studied in buffered aqueous sol... more The aggregation properties of a new sultaine surfactant have been studied in buffered aqueous solution at pH 7.4 under controlled condition of osmolarity.Spontaneously formed sultaine vesicles with a mean diameter of about 1 μm can be observed by optical microscopy. The phase behaviour of the surfactant has been investigated by differential scanning calorimetry (DSC) and Nile Red fluorescence.Two critical vesicular concentrations (CVC1 and CVC2) have been fluorimetrically measured, by using pyrene and Nile Red as the fluorescent probes. The two populations of vesicles behave differently as a consequence of their size.The stability of extruded large unilamellar vesicles (LUV) formed slightly above the CVC1 has been evaluated in the temperature range 25–75 °C by following the rate of spontaneous release of entrapped 5(6)-carboxyfluorescein (CF). The stability of the same vesicles at 70 °C has also been investigated under osmotic stress obtained by adding NaCl or sucrose to the bulk solution.At a sultaine concentration above the CVC2 LUV tend to associate and form stable larger closely packed aggregates as suggested by Dynamic Laser Light Scattering and rheological measurements.► The investigated sultaine surfactant spontaneously forms vesicles in buffered aqueous solution. ► The existence of two populations of vesicles, formed at two CVC values, has been confirmed by means of different techniques (Fluorescence, Dynamic Laser Light Scattering and Rheometry). ► High temperature causes fusion of the large unilamellar vesicles formed above the first CVC. ► The increase of the sultaine concentration above the second CVC causes the association of the vesicles into larger closely packed aggregates.
Langmuir, 2000
This paper reports about the influence of counterions on the solubilization of benzene in aqueous... more This paper reports about the influence of counterions on the solubilization of benzene in aqueous solutions of cetyltrimethylammonium surfactants (CTAX, X = Br - , Cl - , NO 3 - , CH 3 SO 3 - , and (SO 4 ) 2 - 1/2 , CTAB, CTAC, CTAN, CTAMs, and CTAS, respectively) investigated ...
The Journal of Physical Chemistry, 1990
J Am Chem Soc, 1979
ABSTRACT
Journal of the Chemical Society Chemical Communications, 1985
Journal of Chemical Research Synopses, 1988
Journal of the American Chemical Society
ABSTRACT
Langmuir
Cyclization of 2-((3-halopropyl)oxy)phenoxide ion (halo = Br, I; PhBr7 and PhI7, respectively) in... more Cyclization of 2-((3-halopropyl)oxy)phenoxide ion (halo = Br, I; PhBr7 and PhI7, respectively) in micelles is a model for S N 2 reactions of nucleophilic anions at micelle−water interfaces. Sulfobetaine micelles of dodecyldimethylammoniopropanesulfonate (C 12 H 25 N + (CH 3 ) 2 (CH 2 ) 3 ...
Langmuir
The phase diagram of the system composed of H 2 O and tributylhexadecylphosphonium bromide (CTBPB... more The phase diagram of the system composed of H 2 O and tributylhexadecylphosphonium bromide (CTBPBr) has been investigated and the phase boundaries determined. CTBPBr solutions undergo critical demixing phenomena and separate into two fluid phases at temperatures close to ...
The Journal of Physical Chemistry, 1989
Conclusions The surface active sites of V2O5 catalyst under the promoting effect of MOO, were elu... more Conclusions The surface active sites of V2O5 catalyst under the promoting effect of MOO, were elucidated as follows. 1. The surface concentration of redox sites is increased by addition of MOO, to V205 catalysts. The surface V=O species are newly formed on the various crystal ...
Journal of Mining and Metallurgy, Section B: Metallurgy, 2009