Rheological investigation of thermal transitions in vesicular dispersion

Coppola, Luigi; Youssry, Mohamed; Nicotera, Isabella; Gentile, Luigi

doi:10.1016/j.jcis.2009.06.054

Cited by 18 publications

(18 citation statements)

References 30 publications

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“…Dispersions with a visco-elastic behaviour similar to that of the present system have been previously observed for highly concentrated and dehydrated onion-like vesicles [32], for multilamellar vesicles from zwitterionic surfactants/n-alcohols/ionic surfactants mixtures [33] as well as for decyltrimethylammonium hydroxides/2-hydroxy-1-carboxy-naphthoate systems [34]. This gel-like response at high concentration indicates high interactions between close-packed vesicles [35].…”

Section: Resultssupporting

confidence: 84%

Synthesis and aggregation behaviour of a new sultaine surfactant

Maria¹,

Fontana²,

Siani³

et al. 2011

Colloids and Surfaces B: Biointerfaces

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Section: Resultssupporting

confidence: 84%

Synthesis and aggregation behaviour of a new sultaine surfactant

Maria¹,

Fontana²,

Siani³

et al. 2011

Colloids and Surfaces B: Biointerfaces

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“…The lower boundary (65 mM) of the single MLS region (Figure 1) is lower than previously reported in literature [11], [13], probably because the samples were submitted to equilibration times sufficiently long for the MLS LC-to-SG transition to be complete before starting the heating scans.…”

Section: Resultsmentioning

confidence: 52%

“…In a previous study, we reported on the T p -endotherm for DODAB at 5 mM, which was subsequently associated to the presence of dispersed lamellar structures [1], [12]. More recently, Coppola et al [13] related it to a structural transition from ULVs + lamellar fragments-to-MLVs (multilamellar vesicles) that takes place above 10 mM DODAB, while Wu et al [11] referred to it as the coagel-to-LC transition, occurring above 7.5 mM DODAB.…”

Section: Resultsmentioning

confidence: 85%

“…The T s - and T m -endotherms, as well as their T’ s and T’ m reverses, are undoubtedly related to the ULVs [1], [16], while the T p -endotherm and its reverse T’ p -exotherm are related to MLSs [11], [13], [16]. The physical meaning of the T p -endotherm has not, however, been conclusively elucidated so far.…”

Section: Resultsmentioning

confidence: 99%

“…The dominating structures, however, are highly dependent on DODAB concentration [12]–[14]. The precise concentration range of single ULV or multilamellar structure (MLS) formation is still a subject of controversy [11]–[13].…”

Section: Introductionmentioning

confidence: 99%

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Thermal and Structural Behavior of Dioctadecyldimethylammonium Bromide Dispersions Studied by Differential Scanning Calorimetry and X-Ray Scattering

et al. 2012

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Dioctadecyldimethylammonium bromide (DODAB) is a double chain cationic lipid, which assembles as bilayer structures in aqueous solution. The precise structures formed depend on, e.g., lipid concentration and temperature. We here combine differential scanning calorimetry (DSC) and X-ray scattering (SAXS and WAXS) to investigate the thermal and structural behavior of up to 120 mM DODAB in water within the temperature range 1–70°C. Below 1 mM, this system is dominated by unilamellar vesicles (ULVs). Between 1 and 65 mM, ULVs and multilamellar structures (MLSs) co-exist, while above 65 mM, the MLSs are the preferred structure. Depending on temperature, DSC and X-ray data show that the vesicles can be either in the subgel (SG), gel, or liquid crystalline (LC) state, while the MLSs (with lattice distance d = 36.7 Å) consist of interdigitated lamellae in the SG state, and ULVs in the LC state (no Bragg peak). Critical temperatures related to the thermal transitions of these bilayer structures obtained in the heating and cooling modes are reported, together with the corresponding transition enthalpies.

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Processing effects on bilayer structures formation and rheological behavior of softeners using cationic di(hydrogenated tallow)dimethylammonium chloride aqueous dispersions

de Castro,

Ferreira,

Loh

2024

J Surfact & Detergents

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The use of softeners is essential for enhancing laundered fabrics and hair textures after washing. For these, products based on double‐tailed cationic surfactants are used to reduce friction and static electricity, resulting in softer and smoother fibers. These surfactants form lamellar phases in water, which can be turned into vesicles and other bilayer aggregates upon shearing, greatly impacting on the rheological properties of these formulations. This study aims at elucidating how some parameters of the formulation process impact bilayer structures formation and the product rheology, using di(hydrogenated tallow)dimethylammonium chloride (DHTDMAC) aqueous dispersions as model system. Small angle X‐ray scattering (SAXS) analyses revealed lamellar phases starting from 3% DHTDMAC, with a bilayer thickness of 1.90 ± 0.03 nm, indicating significant carbon chain interdigitation. At this concentration (3%), bilayers exhibited a repetition distance of 69 nm, unveiling a behavior close to the one predicted for infinite swelling, in which lamellar structures persisted even at high dilution. Temperature plays a significant role in the rheological behavior, with elevated temperatures favoring vesicle formation, resulting in reduced apparent viscosity due to lower resistance of vesicles to flow. Upon heating, differential scanning calorimetry (DSC) analyses revealed a transition from Lβ (gel) to Lα (fluid) structures between 28 and 41°C, which was further confirmed by X‐ray diffraction (XRD). Both structural and thermotropic features observed were discussed and compared to information reported for a high‐purity grade homologue of DHTDMAC, dioctadecyldimethylammonium chloride (DODAC) mixed with water. These findings deepen the understanding of fabric softener formulation and the impact of bilayer structures formation on their properties, and should be used to optimize new formulations, enhancing their overall performance and sensorial quality.

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Rheological investigation of thermal transitions in vesicular dispersion

Cited by 18 publications

References 30 publications

Synthesis and aggregation behaviour of a new sultaine surfactant

Synthesis and aggregation behaviour of a new sultaine surfactant

Thermal and Structural Behavior of Dioctadecyldimethylammonium Bromide Dispersions Studied by Differential Scanning Calorimetry and X-Ray Scattering

Processing effects on bilayer structures formation and rheological behavior of softeners using cationic di(hydrogenated tallow)dimethylammonium chloride aqueous dispersions

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