Abstract:
The invention is directed to delayed gelation agents comprising a degradable polymeric cage containing therein one or more gelation agents. The cage degrades in situ, e.g, in an oil reservoir, thus releasing the gelation agent(s), which can then crosslink second polymers in situ to form a gel.
Abstract:
The invention is directed to crosslinked water-soluble swellable polymers, methods for making same and their various uses. More particularly, the invention relates to a composition comprising expandable polymeric particles being made with 0.1-5% hydrophobic monomers and labile crosslinkers and stable crosslinkers, said particles mixed with a fluid. A particularly important use is as an injection fluid in petroleum production, where the expandable polymeric particles are injected into a well and when the heat and/or pH of the target zones in the formation cause degradation of the labile crosslinker and when the particle expands, the hydrophobic groups associate to form a hydrophobically associative polymer, thus diverting water to lower permeability regions and improving oil recovery.
Abstract:
The invention is directed to long lasting crosslinked water-soluble swellable polymers, methods for making same, and their uses. More particularly, the invention relates to a composition comprising expandable polymeric particles having cationic sites as well as labile crosslinkers and stable crosslinkers, said particle mixed with a fluid. A particularly important use is as an injection fluid in petroleum production, where the expandable polymeric particles are injected into a target zones in the reservoirs and when the heat and/or pH of the reservoir cause degradation of the labile crosslinker and when the particle expands, the cationic sites in the polymer adsorb to the rock in the formation, thus diverting water to lower permeability regions and improving oil recovery. However, many other uses are possible.
Abstract:
La invención está dirigida a polímeros expandibles solubles en agua entrelazados estables y métodos para hacer los mismos. De modo más particular la invención se refiere a una composición que comprende partículas poliméricas expandibles que tienen sitios aniónicos y entrelazadores lábiles y entrelazadores estables, la partícula mezclada con un fluido y un entrelazador catiónico que es capaz de entrelazar de manera adicional la partícula a la degradación del entrelazador lábil y la exposición de los sitios aniónicos para formar un gel. Un uso particularmente importante es como un fluido de inyección en la producción de petróleo, en donde las partículas poliméricas expandibles son inyectadas dentro de la zona de objetivo y cuando el calor y/o el pH adecuado de la zona de objetivo ocasionan la degradación del entrelazador lábil y la partícula se expande, el entrelazador catiónico entrelaza el polímero para formar un gel, derivando por tanto el agua hacia las regiones de menor permeabilidad y mejorando la recuperación de petróleo.
Abstract:
An implantable biomaterial scaffold having islet cells or small islet cell clusters attached thereto in a multilayer. The cells are derived by enzymatic dispersion and/or calcium depletion of large adult intact islets.
Abstract:
A tissue engineering scaffold for growing cells can include a plurality of biocompatible microspheres linked together to form a three-dimensional matrix. The matrix can include a plurality of pores for growing cells. The biocompatible microspheres can include first and second sets of microspheres. The first set of microspheres can have a first characteristic, and a first predetermined spatial distribution with respect to the three-dimensional matrix. The second set of microspheres can have a second characteristic that is different from the first characteristic, and a second predetermined spatial distribution that is different from the first predetermined spatial distribution with respect to the three - dimensional matrix. The first and second characteristics can selected a composition, polymer, particle size, particle size distribution, type of bioactive agent, type of bioactive agent combination, bioactive agent concentration, amount of bioactive agent, rate of bioactive agent release, mechanical strength, flexibility, rigidity, color, radiotranslucency, radiopaqueness, or the like.
Abstract:
Compositions and methods for making a composition comprising a polymer and one or more chelators covalently coupled to polymer, wherein the one or more chelators has a benzene ring with more than one hydroxyl group at any position that is free, or a derivative of the chelator, or a salt of the chelator and methods of use.
Abstract:
The invention is directed to polymers that self-crosslink at acidic pH or can be crosslinked by phenolic agents in brine. Such polymers have lower viscosity and can be pumped deep into reservoirs, where they will cross link in situ, thus increasing their viscosity and/or form a gel and blocking thief zones. Methods of making and using such polymers are also provided.
Abstract:
A scaffold having islet cells or small islet cell clusters attached thereto in a multilayer, and a micro-mold having divots for culturing islets, wherein islet formation is influenced by the shape and dimensions of the divots are disclosed.