Water-soluble polymeric particle embedded cryogels: Synthesis, characterisation and adsorption of haemoglobin

Making cryogels, which are among today’s accepted adsorbents, more functional with different methods, has been one of the subjects spent overtime. In this study, water-soluble poly(maleic anhydride-alt-acrylic acid) polymer embedded in poly(2-hydroxyethyl methacrylate) cryogels. Copper ions were then immobilised to this structure, and this polymer was used for adsorption of haemoglobin from aqueous systems. Adsorption interaction was carried out on an electrostatic basis, and approximately 448.62 mg haemoglobin/g polymer adsorption capacity value was obtained. It was found that the same material has managed to maintain its adsorption ability by 90.3% even after the use of it five times in the adsorption/desorption cycle. The adsorption interaction was determined to be appropriate for the Langmuir model by isotherm studies. The change in Gibbs free energy value was calculated as −2.168 kJ/mol.

pH-Insensitive Polymeric Particles for Enhanced Oil Recovery in Reservoirs With Fractures

Summary Many carbonate reservoirs have natural fractures that reduce the sweep efficiency of displacement processes. The goal of this study is to improve oil recovery by reducing fluid bypassing caused by fractures, especially in carbon dioxide (CO2) floods. The pH-insensitive polymeric particles (PIPPs) synthesized in this study can plug fractures in reservoir rocks and divert fluid flow into the rock matrix. PIPPs swell in brine similar to polymeric particle gels (PPGs) published in literature; the swelling is a function of brine salinity. A PIPP expands many times (≈35 times) in deionized (DI) water, but swells only approximately 3 times in very-high-salinity (20 wt% NaCl) brine. The swelling of the particles is independent of pH in the range of 2 to 12. The swelling process is reversible with salinity. In water without divalent cations, these particles are stable at 80°C for at least a month. Coreflood results show that these small particles can be transported through fractures during high-salinity-brine injection and reduce the flow capacity of the fractures during low-salinity-brine injection. Subsequently, the injection fluid (brine, toluene, or CO2) is diverted into the matrix, and recovers oil from previously unswept matrix. PIPP injection increases waterflood recovery in cores with full fractures and half fractures connected to the inlet. PIPP placement also increases oil recovery for tertiary miscible/CO2 floods.

Surface induced crystallization of polymeric nano-particles: effect of surface roughness

Molecular dynamics simulations are conducted to study the crystallization of a polymeric system as a drop in an isolated state and on a surface. It is shown that crystallization kinetics for the polymeric system as a particle on a smooth surface is much faster than in the isolated form. We show however that as the surface becomes rough the crystallization rate of the polymeric particle decreases. The effect of roughness was compared for two cases of a polymer drop, partially (Wenzel state) and fully (fully confined) wetting the cavities on a rough surface. In both cases it was observed that crystallization was slower than that on a smooth surface, and crystal growth rate was decreased by increasing the characteristic roughness ratio. The crystallization on rough surfaces was still faster than that of the isolated polymer drop.