Search results for " MICELLES"

POLYMERIC MICELLES AS TUNABLE OFF-ON-OFF pH WINDOW BIOSENSORS.

2009

POLYMERIC MICELLES BASED ON A PHOSPHOLIPID/ POLYASPARTAMIDIC COPOLYMER FOR BECLOMETHASONE DIPROPIONATE DELIVERY TO THE LUNGS

2010

POLYMERIC MICELLES FOR DRUG TARGETING TO THE BRAIN

2008

Small angle scattering study of poly(methylmethacrylate)-block-poly(ethylene oxide) block co-polymer in aqueous solution

2005

A combined Small Angle X ray (SAXS) and Neutron (SANS) Scattering study of aqueous solutions of a symmetric block copolymer consisting of poly(methyl methacrylate) (PMMA) and poly(ethylene oxide) (PEO) moieties is presented. The polymer forms slightly polydisperse spherical micelles in a wide range of concentration (0.03 – 6.7 w/V) and temperature (20°C ≤ T ≤ 65°C). A good description of the SANS data is obtained using a polydisperse core-shell model with a structure factor for a modified hard sphere potential. By increasing the concentration at constant T we observed a decrease of the aggregation number and an increase of solvation of PEO groups in the shell, opposite to what happens by in…

Halloysite nanotubes as nanoreactors for heterogeneous micellar catalysis

2021

Abstract Hypothesis Electrostatic attractions between the anionic head group of sodium alkylsulphates and the positively charged inner surface of halloysite nanotubes (HNTs) drive to the formation of tubular inorganic micelles, which might be employed as nanoreactors for the confinement of non polar compounds in aqueous media. On this basis, sodium alkylsulphates/halloysite hybrids could be efficient nanocatalysts for organic reactions occurring in water. Experiments Sodium decylsulphate (NaDeS) and sodium dodecylsulphate (NaDS) were selected for the functionalization of the halloysite cavity. The composition, the structure and the surface charge properties of the hybrid nanotubes were dete…

Structure, stability, and fragmentation of sodium bis(2-ethylhexyl)sulfosuccinate negatively charged aggregates in vacuo by MD simulations.

2014

Negatively charged supramolecular aggregates formed in vacuo by n bis(2-ethylhexyl)sulfosuccinate (AOT(-)) anions and n + n(c) sodium counterions (i.e., [AOT(n) Na(n+nc)](nc)) have been investigated by molecular dynamics (MD) simulations for n = 1 to 20 and n(c) = -1 to -5. By comparing the maximum excess charge values of negatively and positively charged AOTNa aggregates, it is found that the charge storage capability is higher for the latter systems, the difference decreasing as the aggregation number increases. Statistical analysis of physical properties like gyration radii and moment of inertia tensors of aggregates provides detailed information on their structural properties. Even for …

Surfactant self-assembly in the gas phase: Bis(2-ethylhexyl)sulfosuccinate- alkaline metal ion aggregates

2008

Molecular dynamics (MD) simulations were conducted for systems in vacuo consisting of n AOT anions (bis(2-ethylhexyl)sulfosuccinate ions) and n 1 or n Na+ ions up to n = 20. For n = 15, positively charged systems with Li+, K+, and Cs+ cations were also considered. All systems were observed to form reverse micelle-like aggregates whose centre is occupied by cations and polar heads in a very compact solid-like way, while globally the aggregate has the form of an elongated and rather flat ellipsoid. Various types of statistical analyses were carried out on the systems to enlighten structural and dynamical properties including gyration radius, atomic pair correlation functions, atomic B-factor …

Self-assembly in surfactant-based mixtures driven by acid–base reactions: bis(2-ethylhexyl) phosphoric acid–n-octylamine systems

2013

Structural and dynamic features of bis(2-ethylhexyl) phosphoric acid (HDEHP)-n-octylamine (NOA) mixtures as a function of the NOA mole fraction (X-NOA) have been investigated by SAXS, WAXS, IR, dielectric spectroscopy and polarized optical microscopy. In the 0 <= X-NOA < 0.5 range, mixtures are transparent liquids, while the abrupt formation of a waxy solid characterized by an hexagonal bidimensional structure occurs at X-NOA = 0.5. Such a composition-induced phase transition results from the synergetic effect of the progressive increase in number density of ordered HDEHP-NOA nanodomains with X-NOA. Mainly driven by an HDEHP to NOA proton transfer, the increase of structural order with X-NO…

TUNABLE SENSOR FOR PH WINDOWS IN BIOCAMPITBLE POLYMERIC MICELLES SISTEM

2009

Inverse Thermogelation of Aqueous Triblock Copolymer Solutions into Macroporous Shear-Thinning 3D Printable Inks

2020

Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in ditIerent areas including drug delivery, tissue engineering, regenerative medicine, and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in an aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)-block-poly(2-phenyl-2-oxazine)-block-poly(2-methyl-2-oxazoline) (PMeOx-b-PPheOzi-b-PMeOx) undergo inverse thermogelation below a critical temperatur…