Ewa Dluska

Mass transfer in gas-liquid Couette-Taylor flow reactor

The results of the measurements of mass transfer coe

Mass transfer in gas-liquid Couette-Taylor flow in membrane reactor

cients for the physical (CO /water) and chemical absorption (oxidation of benzaldehye) have been presented. The collected experimental data have been correlated with the energy dissipated in the system. High values of the mass transfer coe

The Multiple Emulsion Entrapping Active Agent Produced via One-Step Preparation Method in the Liquid–Liquid Helical Flow for Drug Release Study and Modeling

cients, k a, of the order of 10 s have been obtained. 2001 Elsevier Science Ltd. All rights reserved.

Multiple emulsions as effective platforms for controlled anti-cancer drug delivery

A concept of membrane CTF (Couette-Taylor flow) reactor applicable to gas-liquid processes has been presented. Its fundamental hydrodynamic and kinetic properties have been discussed. In the experiments high values of the mass transfer coefficients, k L a, of the order of 0.1 s -1 have been obtained and a relatively weak influence of the liquid viscosity on the values of the mass transfer coefficients has been observed. To eliminate moving elements of the reactor, a replacement of the rotor by a static helical ribbon guide which forces the helicoidal flow of the fluid has been proposed for the same operating conditions.

Multifunctional emulsion structures for encapsulation and modified release of active ingredients

The paper presents a theoretical mass transfer model of the release process of active agent from complex dispersed systems such as multiple emulsions, microemulsions, micro/nanoparticles. The model is characterized by five parameters describing internal structure of the delivery system and the conditions of the release environment which enable the determination of the release rate and its sensitivity to the process parameters. The model was validated by experimental data of an active component release from two sets of multiple emulsions prepared via a novel one-step emulsification method in the continuous Couette-Taylor Flow contactor. The simulation of release profiles confirmed the importance of the internal multiple emulsions structure (drop size, packing volume) as well as the intensity of external mixing in the modeling of the controlled release process. The presented model allowed the mass released to be determined with satisfactory agreement with experimental data after optimization of parameters describing internal emulsions structure.

Mass Transfer Modelling in the Couette-Taylor Flow Reactor for the Oxidation Process of Organic Contaminants

AIM Developing pH-responsive multiple emulsion platforms for effective glioblastoma multiforme therapy with reduced toxicity, a drug release study and modeling. MATERIALS & METHODS Cancer cell line: U87 MG, multiple emulsions with pH-responsive biopolymer and encapsulated doxorubicin (DOX); preparation of multiple emulsions in a Couette-Taylor flow biocontactor, in vitro release study of DOX (fluorescence intensity analysis), in vitro cytotoxicity study (alamarBlue cell viability assay) and numerical simulation of DOX release rates. RESULTS The multiple emulsions offered a high DOX encapsulation efficiency (97.4 ± 1%) and pH modulated release rates of a drug. Multiple emulsions with a low concentration of DOX (0.02 μM) exhibited broadly advanced cell (U87 MG) cytotoxicity than free DOX solution used at the same concentration. CONCLUSION Emulsion platforms could be explored for potential delivery of chemotherapeutics in glioblastoma multiforme therapy.

One-step preparation method of multiple emulsions entrapping reactive agent in the liquid–liquid Couette–Taylor flow

Multifunctional emulsion structures for encapsulation and modified release of active ingredients

Reducing fouling and boundary-layer by application of helical flow in ultrafiltration module employed for radioactive wastes processing

The Couette-Taylor Flow reactor (CTF reactor) is characterised by high values of the mass transfer parameters. Our previous mass transfer investigations revealed high values of the volumetric mass transfer coefficients (of the order of 10-1 s-1) and the specific interfacial area, higher than those obtained in the stirred tanks. The experimental results of benzaldehyde oxidation considered potential application of the CTF reactor in oxidising organic liquids and contaminants. Owing to its tubular construction the CTF reactor is suitable to operate in a continuous process at elevated pressures. In one of the advanced oxidation methods, i.e. the Wet Air Oxidation, some fundamental problems emerge, e.g. how to intensify diffusional mass transfer. In the case of technical apparatus, even when solid catalysts are applied, diffusional factors control the overall process rate. Under such circumstances the CTF reactor is applicable. The mass transfer correlation was proposed as the first step in wet air oxidation modelling.