Search results for "Solubilization"

A crystalline and free-standing silver thiocarboxylate thin-film showing high green to yellow luminescence

2016

The simple direct synthesis of Cu(ii) and Ag(i) salts and thiobenzoic acid under ambient conditions allows the preparation of two bidimensional coordination polymers [M(TB)] (TB = thiobenzoate; M = Cu (1) or Ag (2)). Their electrical and luminescent properties show that these are multifunctional materials. Interestingly 1 and 2 undergo a reversible solubilization process. This unusual feature and their simple preparation allow us to prepare a crystalline and free-standing thin-film of 2, using an interfacial procedure, which shows a remarkable thermochromic luminescence.

Interactions of α-tocopherol with biomembrane models: Binding to dry lecithin reversed micelles

2005

Abstract The state of α-tocopherol (Vitamin E) in solutions of dry lecithin reversed micelles dispersed in an apolar medium has been investigated as a function of the Vitamin E to surfactant molar ratio (RVE) at fixed surfactant concentration by FT-IR, 1H NMR and SAXS with the aim to emphasize the role played by anisotropic intermolecular interactions and confinement effects as driving forces of its partitioning between apolar bulk solvent and polar nanodomains and of mutual Vitamin E/reversed micelle effects. It has been found that its binding strength to reversed micelles, triggered by steric and orientational constrains, is mainly regulated by specific interactions between the hydrophili…

Antiepileptic effect of dimethyl sulfoxide in a rat model of temporal lobe epilepsy.

2012

Dimethyl sulfoxide (DMSO) is an amphipathic molecule widely used to solubilize water-insoluble compounds. In many studies it was reported that DMSO is capable of affecting several biological processes, thus resulting in a potential cause for the misinterpretation of experimental data. Recent papers showed that DMSO modified the brain bioelectric activity in animal models of epilepsy. In an in vivo model of temporal lobe epilepsy in the rat, we examined the effects of different doses (10%, 50% and 100%) of DMSO on the maximal dentate activation (MDA). The results show that DMSO induced a dose-dependent significant reduction of the electrically induced paroxysmal activity.

Halloysite Nanotubes: Interfacial Properties and Applications in Cultural Heritage

2020

The peculiar surfaces of halloysite nanotubes and their biocompatibility are attracting the interest of researchers based on the wide range of attainable applications. The large aspect ratio of this nanotubular material ensures promising properties as a reinforcing agent in polymeric matrixes, such as cellulose and its derivatives, that entail strengthening due to, for instance, aging-induced degradation. The halloysite cavity has a suitable size for hosting a large variety of active species such as deacidifying (calcium hydroxide) and flame retardant agents (fluorinated surfactants) for a controlled and sustained release relevant to the conservation of cultural heritage. Additionally, anio…

Structure of Hybrid Materials Based on Halloysite Nanotubes Filled with Anionic Surfactants

2016

The structures of pristine halloysite nanotubes (HNTs) and ones functionalized by anionic surfactants (sodium dodecanoate and sodium dodecyl sulfate) were investigated by small angle neutron scattering (SANS). These experiments evidenced the structural organization of the surfactants adsorbed onto the HNT cavity and the importance of the surfactant headgroup. Contrast matching experiments were employed in order to mask the dominant scattering effect of the clay hollow nanotubes and to focus on the surfactant organization within the lumen. Further investigation on the mesoscopic structure of the investigated materials was carried out by electric birefringence (EBR), which allowed study of th…

1993

Recent achievements in the field of micellar polymers, or «polysoaps» are described. Taking advantage of zwitterionic model polymers, systematic variations of the molecular architecture have provided an improved understanding of the relationship between the molecular structure of the polymers and their key properties such as surface activity and solubilization capacity. Useful rules are established, which take into account much of the previous data in the literature

Halloysite Nanotube with Fluorinated Lumen: Non-Foaming Nanocontainer for Storage and Controlled Release of Oxygen in Aqueous Media

2014

Halloysite clay nanotubes were selectivity modified by adsorbing perfluoroalkylated anionic surfactants at the inner surface. The modified nanotubes formed kinetically stable dispersions due to the enhanced electrostatic repulsions exercised between the particles. We proved that the modified nanotubes can be used as non-foaming oxygen nanocontainers in aqueous media. The gas release from supersaturated dispersions can be controlled by external stimuli and system composition. In conclusion, we managed to put forward an easy strategy to develop smart materials from natural nanoclays, which can endow important applications like the storage and delivery of gas.

A mathematical approach to predict the solids concentration in anaerobic membrane bioreactos (AnMBR): Evaluation of the volatile solids solubilization

2020

[EN] Anaerobic Membrane Bioreactors (AnMBR) are gaining attention as a suitable approach for sustainable low-strength wastewater treatment, as they bring together the advantages of both anaerobic treatments and membrane bioreactors. However, increasing the sludge retention time (SRT) necessary to favor hydrolysis increases the suspended solids concentration potentially leading to decreased permeate flux. Therefore, the availability of a mathematical approach to predict the solids concentration within an AnMBR can be very useful. In this work, a mathematical model describing the volatile solids concentration within the reactor as a function of the operating parameters and the influent charac…

Complex permittivity of FeCl3/AOT/CCl4 microemulsions probed by AC impedance spectroscopy

2009

Abstract The complex permittivity of FeCl 3 /AOT/CCl 4 microemulsions in the 1–10 5  Hz frequency range has been measured by the conventional AC complex impedance technique. Measurements as a function of the volume fraction of the dispersed phase (FeCl 3  + AOT) and temperature at fixed salt-to-AOT molar ratio ( R , R  = 0.5) show that the entrapment of FeCl 3 clusters significantly enhances the local permittivity of the AOT reverse micelles and the number density of charge carriers resulting from the peculiar state of the confined inorganic salt. An estimate of the apparent static permittivity of the FeCl 3 ionic clusters entrapped in the core of AOT reverse micelles gives the very high an…

Amphiphilic derivatives of a polyaspartamide: their aggregation and solubilization ability.Tensiometric and spectrophotometric studies

2006

The self-aggregation and solubilization capability of a series of amphiphilic copolymers obtained by derivatisation of polymeric chain of α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) with polyethylene glycols (PEG, being different molecular weight 2000 or 5000 Da, PEG2000 and PEG5000, respectively) and/or hexadecylamine alkyl chain (C16), namely PHEA–PEG2000, PHEA–PEG5000, PHEA–C16, PHEA–PEG2000–C16 and PHEA–PEG5000–C16, have been evidenced by performing systematic tensiometric and spectrophotometric studies. All measurements have been performed at 25.0 °C over a wide copolymer concentration range. The tensiometric results have shown that, for all copolymers studied, the surface tension…