Galina Rodionova

Gas-phase esterification of microfibrillated cellulose (MFC) films

The barrier properties of microfibrillated cellulose (MFC) films were improved by heterogeneous gas-phase esterification using various combinations of trifluoroacetic acid anhydride, acetic acid and acetic anhydride. The temperature, reagent ratio and reaction time were varied in the experimental design. The effects of two different purification procedures on the barrier properties of esterified MFC films were investigated. Washing with water did not affect the barrier properties compared to those of the films that were not washed, while the use of diethyl ether led to improved barrier properties as measured by the contact angle (CA) of water. The chemical composition of the modified films was studied by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Alterations in hydrophobicity and oxygen permeability were evaluated using dynamic CA and oxygen transmission rate measurements, respectively.

Preparation and Characterization of Reference Fluids to Mimic Flow Properties of Crude Oil Emulsions (w/o)

The multiphase flow models, such as OLGA® and LedaFlow®, have been developed based on the multiphase flow experiments, where base oils have been widely used. However, physicochemical properties of the base oils and crude oils are mostly not similar and therefore liquid–liquid flow properties of them in the pipes can be very different. Consequently, it is very important to get the fluids behave in a similar way with the produced crude oils. In this study, the reference fluids with flow properties similar to the produced crude oils and their corresponding emulsions have been prepared. The steps involved to prepare the reference fluids for crude oils were also discussed. GRAPHICAL ABSTRACT

Electrorheological Behavior of Crude Oil and Synthetic Reference Fluid Emulsions

The current work describes and compares the characteristics of water-in-oil emulsions prepared from a North Sea acidic crude oil and a synthetic reference fluid. The reference fluid was developed with the main purpose of mimicking electrostatic destabilization of crude oil emulsions based on comparison of emulsion viscosities, mean droplet sizes, droplet size distributions, and separation rates. Emulsions of both fluids were destabilized by means of electrostatic forces under application of alternating current electric fields, and similar viscosities before and after the treatment were confirmed. Differences in coalescence mechanisms were registered as a result of different chemical composition, types, and concentrations of interfacially active species. GRAPHICAL ABSTRACT

Foreword: The Bridge between Colloid Chemistry and Fluid Dynamics

GRAPHICAL ABSTRACT