341 results about "Cationic polyelectrolytes" patented technology

A medical device and method for transportation and release of a therapeutic agent into a mammalian body are disclosed. The medical device is coated with alternating layers of a negatively charged therapeutic agent and a cationic polyelectrolyte, following a controlled adsorption technique. The method is simple, with minimal perturbation to the therapeutic agent and uses clinically acceptable biopolymers such as human serum albumin. The amount of the therapeutic agent that can be delivered by this technique is optimized by the number of the layers of the therapeutic agent adsorbed on the surface of medical device. There is a washing step between alternate layers of the therapeutic agent and cationic polyelectrolyte carrier, so that the amount of the therapeutic agent on the insertable medical device represents the portion that is stably entrapped and adsorbed on to the medical device. The insertable medical device and method according to this invention are capable of reproducibly delivering therapeutic agent to a site in a mammalian body, and allow for a highly reproducible and controllable release kinetics of the therapeutic agent.

A solution for soft, hydrogel contact lenses includes a polyether that is controllably released into an eye's tear film when the lens is worn. Polyether components of the subject solution are released from the soft contact lens material matrix over long time periods to produce longer lasting wetting performance, improved lubricity, improved comfort, and / or reduced feeling of dryness from wearing contact lenses. The solution further includes a cationic polyelectrolyte.

A method for preparing aqueous furnish to be used in paper or paper board manufacturing. Filler and / or fibers are treated with cationic polyelectrolyte and nanofibrillated cellulose. A furnish and a paper or a paper board.

A coating composition for pre-treating a substrate prior to inkjet printing thereon, and an inkjet receiving medium comprising a substrate and having a topmost layer coated thereon, where the coating composition and topmost layer comprise one or more aqueous-soluble salts of multivalent metal cations, a cationic polyelectrolyte comprising amidine moieties, and one or more second polymer which is distinct from the cationic polyelectrolyte and which is selected from the group consisting of a polyamide-epichlorohydrin, a polyamine solution polymer, and a waterborne or water-dispersible polyurethane. The topmost layer is advantageously at a solid content of from 0.1 to 5 g / m2, and comprises from 30-90 wt % of the one or more aqueous soluble salts of multivalent metal cations, at least 0.01 g / m2 of the cationic polyelectrolyte comprising amidine moieties, and at least 0.005 g / m2 of the second polymer which is distinct from the cationic polyelectrolyte comprising amidine moieties.

One aspect of the present invention relates to a method of coating a surface, comprising sequentially depositing on a surface, under pH-controlled conditions, alternating layers of polymers to provide a coated surface, wherein a first polymer is selected from the group consisting of pH dependent cationic polyelectrolytes and neutral polymers, and a second polymer is selected from the group consisting of anionic polyelectrolytes, thereby permitting or preventing cell adhesion to said coated surface. In certain embodiments, the aforementioned method provides a coated surface to which cell adhesion is permitted. In certain embodiments, the aforementioned method provides a coated surface to which cell adhesion is prevented. Another aspect of the present invention relates to a method of rendering a surface cytophilic, comprising the step of coating a surface with a polyelectrolyte multilayer film, which film swells to less than or equal to about 150% of its original thickness when exposed to an aqueous medium. Another aspect of the present invention relates to a method of rendering a surface cytophobic, comprising the step of coating a surface with a polyelectrolyte multilayer film, which film swells to greater than or equal to about 200% of its original thickness when exposed to an aqueous medium.

A medical device and method for transportation and release of a therapeutic agent into a mammalian body are disclosed. The medical device is coated with alternating layers of a negatively charged therapeutic agent and a cationic polyelectrolyte, following a controlled adsorption technique. The method is simple, with minimal perturbation to the therapeutic agent and uses clinically acceptable biopolymers such as human serum albumin. The amount of the therapeutic agent that can be delivered by this technique is optimized by the number of the layers of the therapeutic agent adsorbed on the surface of medical device. There is a washing step between alternate layers of the therapeutic agent and cationic polyelectrolyte carrier, so that the amount of the therapeutic agent on the insertable medical device represents the portion that is stably entrapped and adsorbed on to the medical device. The insertable medical device and method according to this invention are capable of reproducibly delivering therapeutic agent to a site in a mammalian body, and allow for a highly reproducible and controllable release kinetics of the therapeutic agent.

The invention discloses a polyelectrolyte nanometer flame-retardant coating by adoption of layer-by-layer assembly and a preparation method thereof. The preparation method comprises following steps of: 1), preprocessing: putting and soaking base material into an acid solution and cleaning and drying base material with water; 2), self-assembly: putting and soaking pre-processed base material to a cationic polyelectrolyte solution in order to from a layer of ion membrane, taking out the layer of ion membrane and cleaning the ion membrane with water for drying, putting and soaking the ion membrane into the cationic polyelectrolyte solution in order to form an layer of anionic membrane, and cleaning the layer of anionic membrane with water and drying; sequentially repeating above self-assembly process for multiple times so that the polyelectrolyte nanometer flame-retardant coating is prepared by adoption of layer-by-layer assembly on the surface of the base material. The polyelectrolyte nanometer flame-retardant coating by adoption of layer-by-layer assembly and the preparation method thereof have following beneficial effects: the polyelectrolyte nanometer flame-retardant coating is green and eco-friendly and has a simple and feasible preparation method; damage to the internal structure of base material is avoided; high flame-retardant efficiency is obtained; and the preparation method is suitable for formation of flame-retardant coatings on material surfaces including fabric, wood, foam and plastics.

The invention provides an artificial hollow micro-nano motor and a preparation method thereof, relating to artificial motors and preparation methods thereof and solving the problem that the existing solid spherical motor, tubular motor and linear motor are poor in loading performance. The artificial hollow micro-nano motor is made from a polyelectrolyte double-layer skeleton and a catalyst or is made from a cationic polyelectrolyte skeleton and the catalyst; and the preparation method of the artificial hollow micro-nano motor comprises the following steps of: (1) preparing micro-nano catalyst particles; (2) synthesizing a core substrate; (3) synthesizing an artificial hollow micro-nano motor skeleton; and (4) removing the core substrate by using a template solvent so as to obtain the artificial hollow micro-nano motor. The preparation method has the advantages of simplicity and feasibility, stable process, good repeatability and convenience in mass production, and the prepared artificial hollow micro-nano motor is good in transportability and loading function, has a wide application prospect in a plurality of aspects, such as drug release control, blood purification, clinical diagnosis, and is simple in operation. The artificial hollow micro-nano motor prepared by the preparation method provided by the invention is applicable to the medical field.

The invention relates to a preparation method of a layer-by-layer self-assembly forward osmosis membrane and a layer-by-layer self-assembling forward osmosis membrane prepared by the method. The preparation method comprises the steps of carrying out modified treatment on a basic membrane, preparing a cationic polyelectrolyte solution, preparing an anionic polyelectrolyte and preparing a multilayer self-assembling membrane. By adopting the method, the deposition process in the prior art for adsorption only by virtue of an electrostatic effect can be changed, and a coordination effect better than the electrostatic effect is used as the driving force of the deposition process, so that the membrane has the characteristics of high water flux and low salt reverse osmotic quantity, other subsequent processes such as GA cross-linking and UV radiation are not needed, and thus the time for the preparation process can be greatly reduced.

Polishing rate selectivity is increased by providing a polyelectrolyte in the polishing slurry. The polishing selectivity of silicon oxide to silicon nitride is enhanced by using an anionic polyelectrolyte. The polishing selectivity of metals to silicon oxide, silicon nitride and / or silicon oxynitride is increased by using a cationic polyelectrolyte.

The invention discloses a preparation method of a high-throughput and multilayer sandwich type composite nano-filtration membrane. The preparation method includes: performing surface modification on an ultrafiltration basement membrane and (zero-dimensional or one-dimensional and two-dimensional) nano materials to allow the ultrafiltration basement membrane and the nano materials to be electronegative, and using cationic polyelectrolyte as the bridge to alternatively assemble the one-dimensional or zero-dimensional nano materials and two-dimensional sheet layers onto the ultrafiltration basement membrane to obtain the high-throughput composite nano-filtration membrane with a functional layer being two-dimensional nano materials sandwiched with one-dimensional or zero-dimensional nano materials. The preparation method has the advantages that the difficulty that the interlayer spacing of a two-dimensional nano layered membrane is small and the two-dimensional nano layered membrane is easy to deform during high-pressure filtration is solved effectively by the prepared functional layer, membrane throughput can be increased evidently, and the long-term stability of the membrane structure can be kept at the same time; the preparation method is simple in preparation process, and the prepared nano-filtration membrane is high in throughput and promising in application prospect in fields such as dye removing.

A composition and method for a linear or crosslinked cationic polyelectrolyte, involving copolymerization of at least one cationic monomer with at least one neutral monomer and at least one nonionic surfactant monomer.

The invention provides a method for preparing a graphene-loaded nano alloy catalyst, which is characterized by sequentially comprising the following steps of: 1, oxidizing and stripping graphite to obtain GO (Graphene Oxide); 2, carrying out surface functionalization on the GO by cationic polyelectrolyte; 3, carrying out static assembly on binary metal ions because the surface of the functionalized GO the surface is provided with positive charges; and 4, carrying out in-situ reduction on the bounded metal ions and simultaneously reducing the GO into graphene to obtain high dispersion graphene-loaded nano alloy particles which can be directly used as an electro-catalyst of a methanol fuel cell. By the method, the problems that graphene is aggregated and is difficult to disperse, metal atoms are preferably nucleated and grow at the defect positions on the surface of graphene to cause low particle dispersion degree and two metal ions have different reduction speeds to cause inhomogenous alloy components are solved.

The invention relates to a molybdenum disulfide / graphene hollow composite microsphere with a layered porous hollow microsphere-shaped structure, and a synthetic method for the molybdenum disulfide / graphene hollow composite microsphere, and belongs to the technical field of micro-nano composite material preparation and synthesis. The method comprises the steps: firstly preparing a silicon oxide microsphere; secondly assembling a positive ion polyelectrolyte layer on the surface of the silicon oxide microsphere, and enabling the silicon oxide microsphere to be positively electrified; thirdly assembling a oxidized graphene layer on the surface of the positively electrified silicon oxide microsphere, and obtaining a silicon oxide / oxidized graphene composite microsphere; fourthly depositing and growing a molybdenum disulfide nanosheet on the surface of the silicon oxide / oxidized graphene composite microsphere through employing a hydrothermal method, reducing the wrapped oxidized graphene to graphene at the same time, and then obtaining a silicon oxide / graphene / molybdenum disulfide composite microsphere; finally removing a silicon oxide core through employing the hydrothermal method and excessive hydrofluoric acid, and forming the molybdenum disulfide / graphene hollow composite microsphere through synthesis. When the composite microsphere serves as the electrode material of a supercapacitor, the microsphere is large in specific capacitance, is excellent in circulating charging and discharging stability, and presents a good application prospect.

The present invention relates to fluorescent silica microball containing cadmium telluride fluorescence quantum point(s). By using the mixture of water soluble cadmium telluride fluorescence quantum point and ammonia water as oil phase and non-ionic surfactant as emulsifier to form reverse phase micro emulsion and through one-step reaction of hydrolyzing siloxane at room temperature, fluorescent silica microball in core-shell structure is first obtained; and through further deposition and separation, silica microball with cadmium telluride fluorescence quantum point is obtained. Controlling the experiment condition can obtain fluorescent silica microball of particle size adjustable in 30-100 nm, and altering the type of siloxane or adding cationic polyelectrolyte can obtain fluorescent silica microball with several cadmium telluride quantum points, the number of which is controlled by means of changing the amount of the cationic polyelectrolyte.

The present invention is directed to an ophthalmic solution for soft contact lenses for controlled release of polyethers into an eye's tear film. Polyether components of the subject solution are released from the soft contact lens material matrix over long time periods to produce longer lasting wetting performance, improved lubricity, improved end-of-the-day comfort and reduced feeling of dryness from wearing contact lenses. The present invention also includes the use of cationic polyelectrolytes for controlling the swelling of hydrogel contact lenses typically caused by the absorption of high concentrations of polyethers.

The invention discloses a stimulus-responsive self-repair anticorrosive coating material and a preparation method. The coating material comprises a CuO microcapsule and a coating matrix. The CuO microcapsule comprises a capsule core and a capsule core carrier, the capsule core is a corrosion inhibitor, and the capsule core carrier is porous CuO; and the surface of the CuO microcapsule is coated byan anionic polyelectrolyte layer and a cationic polyelectrolyte layer alternately. The invention successfully constructs the anticorrosive coating material with ph responsiveness and self-repair dualefficacy. The porous CuO can improve the loading rate and encapsulation rate of the capsule core substance; at the same time, the anionic polyelectrolyte can be adsorbed on the surface by means of layer-by-layer self-assembly, under the action of Coulomb force, then cationic polyelectrolyte can be adsorbed on the surface, thus improving the dispersibility of the microcapsule in the coating, solving the agglomeration problem of the porous substance CuO, and at the same time improving the bonding performance of the capsule core carrier and the coating matrix, and the anticorrosion performance of the coating material can be further improved.

The invention discloses a layer by layer self-assembly compound nanofiltration membrane based on natural cellulose polyelectrolyte and a preparation method, belonging to the technical field of membrane separation. The preparation method comprises the following steps: firstly, adopting an ultrafiltration membrane as a base membrane for preparing a compound nanofiltration membrane, carrying out chemical modification on the surface of the base membrane to ensure that the surface of the base membrane has a charge property so as to generate static reaction with a polyelectrolyte; and secondly, through alternating depositing anionic and cationic polyelectrolytes, preparing the compound nanofiltration membrane through a layer by layer self-assembly method. According to the preparation method, the adopted cationic polyelectrolyte is a natural cellulose polyelectrolyte; compared with a currently used synthetic polyelectrolyte, the natural cellulose polyelectrolyte is lower in cost, and is an environmental-friendly resource; and the prepared compound nanofiltration membrane containing natural cellulose is good in hydrophilcity and charge performance so that the surface of the membrane is good in pollution resistance; and the compound nanofiltration membrane has a good retaining property for dye molecules such as divalent metal ions such as Ni<2+>, xylenol orange sodium salt, and rhodamine B.

A water-soluble, powdered, cationic polyelectrolyte comprising a copolymer of acrylamide and dimethylaminopropylacrylamide which is essentially free of bifunctional compounds and in whicha) the dimethylaminopropylacrylamide is quaternized;b) the quotient of the intrinsic viscosity of the copolymers divided by the molar ratio of acrylamide to dimethylaminopropylacrylamide is greater than 200; andc) the proportion of the cationic monomers in the polymer is between 4 and 80 mol-%,the copolymer having been obtained by copolymerization of acrylamide and quaternized dimethylaminopropylacrylamide said quaternized dimethylaminopropylacrylamide having been obtained by the reaction of dimethylaminopropylacrylamide with a quaternizing agent in the absence of acrylamide.

The invention belongs to the technical filed of membranes, particularly relates to an inorganic / organic composite nanofiltration membrane. The inorganic / organic composite nanofiltration membrane sequentially comprises a basement membrane, a transition layer, a composite layer and a compact layer, wherein the basement membrane is provided with an ultrafiltration membrane, the transition layer is formed on the surface of the basement membrane by cationic polyelectrolyte and anionic polyelectrolyte through electrostatic self-assembly, the composite layer is formed on the surface of the transition layer by a soluble calcium salt and a soluble carbonate in a in-situ way, and the compact layer is formed on the surface of the composite layer by the cationic polyelectrolyte and the anionic polyelectrolyte in a crosslink way. The precipitation and the in-situ formation of inorganic minerals are controlled through the identification of an inorganic matter precursor due to polyelectrolyte, thus the inorganic / organic composite nanofiltration membrane which is of a shell-simulation shape is obtained, and the inorganic / organic composite nanofiltration membrane is uniform and controllable and has a stable performance. The implementation processes are all carried out in normal temperature, an organic solvent is free, and the inorganic / organic composite nanofiltration membrane is environment friendly and has a good separating effect for Ca<2+>, Mg<2+> and dye molecules of which molecular weights are larger than 370 in water.

The invention provides an antibacterial polyelectrolyte composite nano-fiber membrane and a preparation method thereof. The antibacterial polyelectrolyte composite nano-fiber membrane with an antibacterial performance is prepared from chitosan cationic polymers by using an oxidized bacterial cellulose nano-fiber membrane as a base membrane and utilizing the electrostatic effect between anionic and cationic polyelectrolytes. The antibacterial polyelectrolyte composite nano-fiber membrane has excellent hydrophilia and charge performance, utilizes the electrostatic interaction between the anionic and cationic polyelectrolytes and is compounded with the chitosan cationic polymers by adopting a layer-layer adsorption method, and a multi-layer composite nano-fiber membrane is formed by selecting repeated adsorption and alternate deposition. The antibacterial polyelectrolyte composite nano-fiber membrane protects the unique nano-fiber structure of bacterial cellulose membranes, is controllable in antibacterial layer thickness nanometer grade, and is an ideal medical wound dressing with good antibacterial performance, excellent air permeability and strong water holding capacity.

The present invention belongs to the natural macromolecule materials technical field, in particular to a natural polyampholyte electric field sensitive hydrogel and preparation method. The present invention adopts the blending of natural cationic polyelectrolyte and natural anionic polyelectrolyte, both of which are characterized by good biological compatibility and biological degradation, to prepare natural polyampholyte hydrogel film. Natural polyampholyte hydrogel film is immersed in electrolytic solution and bends under the role of direct current field. The bending direction and bending angle of hydrogel film can be adjusted. The hydrogel film has electric field response in electrolytic solution with varied pH value; and bends toward different directions under acid condition and alkali condition. The properties expand the scope of pH value for electric field sensitive hydrogel; thus leading to bright prospect of widespread application of electric field hydrogel in fields like artificial muscle, sensor, controlled drug release, automatic switch components and separation technology.

A method of bonding an antimicrobial cationic polyelectrolyte to the surface of a substrate is described, wherein the antimicrobial thus attached to the substrate provides the substrate with antimicrobial properties, and at least a portion of the bonded antimicrobial is substantially non-leachable during normal conditions of use and storage. A method of manufacturing an antimicrobial material is described which comprises exposure of the substrate to a solution of antimicrobial cationic polyelectrolyte, followed by drying the exposed substrate thoroughly to impart a non-leaching property to at least a portion of the antimicrobial cationic polyelectrolytes.

The invention discloses a charged TiO2 / polyelectrolyte composite nanofiltration membrane as well as a preparation method and an application thereof, and belongs to the technical field of membrane separation. The preparation method comprises the following steps: firstly, the surface of a base membrane is charged, so that the base membrane and polyelectrolytes can conveniently generate an electrostatic effect; secondly, the composite nanofiltration membrane is prepared with a method for alternatively depositing anionic and cationic polyelectrolytes and performing electrostatic layer-by-layer self-assembly. Inorganic nanoparticles adopted in the preparation method are modified negatively charged / positively charged TiO2 nanoparticles; as TiO2 has the advantages of good photocatalytic performance, good hydrophilicity and the like, TiO2 is combined with layer-by-layer self-assembly to prepare the TiO2 / polyelectrolyte composite nanofiltration membrane; the preparation method is simple and convenient to operate and is an environment-friendly preparation method; moreover, the prepared TiO2-containing composite nanofiltration membrane has very good hydrophilicity and charge performance, has good pollution resistance, is uniform in structure and can be used for removing divalent metal ions such as Ni<2+> and the like in wastewater as well as dye molecules such as dimethylphenol orange, eriochrome black T and the like at the same time, thereby having a good application effect.

The invention discloses a method for assembling polyelectrolyte / inorganic nano-particle multilayer films on the surfaces of wood materials layer by layer, and relates to a method for assembling multilayer films on the surfaces of wood materials layer by layer. The method includes firstly, pre-treating and drying the wood materials; secondly, preparing cationic polyelectrolyte film forming liquid, anionic polyelectrolyte film forming liquid and inorganic nano-particle film forming liquid; thirdly, alternately soaking the wood materials in the cationic polyelectrolyte film forming liquid and the anionic polyelectrolyte film forming liquid to form polyelectrolyte multilayer films; fourthly, alternating soaking the wood materials in the cationic polyelectrolyte film forming liquid, the anionic polyelectrolyte film forming liquid and the inorganic nano-particle film forming liquid to obtain the wood materials with the polyelectrolyte / inorganic nano-particle multilayer films which are formed on the surfaces of the wood materials. The method has the advantages that problems of high cost, the requirement on large devices, certain environmental pollution, certain destruction on physical and chemical properties of wood materials and long relative treatment periods of an existing technology for improving the functionality of the wood materials can be solved, and the method is used for assembling the polyelectrolyte / inorganic nano-particle multilayer films on the surfaces of the wood materials layer by layer.

The invention relates to compositions and methods of treatment employing compositions including a cationic polyelectrolyte, without any anionic polyelectrolytes, so that no polyelectrolyte complex (PEC) is formed. In addition to not forming PECs, and being free of anionic water-soluble polymers (i.e., an anionic polyelectrolyte polymer that could form a PEC with the cationic polyelectrolyte), the composition is also free of random copolymers, block copolymers, coacervates, precipitates, and silicone copolymers. The composition may be a concentrate, to be diluted prior to use to treat a surface.

The invention relates to a galvanic anode system for the corrosion protection of steel, comprised of a solid electrolyte and a galvanic anode material, preferably zinc and its alloys, glued to the solid electrolyte or embedded in the solid electrolyte. The solid electrolyte is characterised by a high ion conductivity and comprises at least one anionic and / or cationic polyelectrolyte and / or preferably at least one compound that forms complex compounds with the anode material, preferably with zinc. The solid electrolyte is produced by applying a coating agent, preferably as an aqueous dispersion or suspension, to the steel and / or to the mineral substructure, preferably to concrete. The anode material is characterised in that it forms a galvanic element in combination with the solid electrolyte and the steel to be protected, in which the steel forms the cathode. The inventive galvanic anode system is further characterised in that the anode material is applied to the surface of the solid electrolyte as a foil, network or grid, preferably by gluing, and / or is embedded in the solid electrolyte.

The invention discloses a method for preparing antibacterial paper on the basis of an interlayer self-assembling technology. In the method, cationic polyelectrolyte chitosan biguanide hydrochloride (CGH) with an antibacterial function, and anionic polyelectrolyte carboxymethyl cellulose sodium (CMC) are alternately deposited on the surface of a bleached kraft hardwood fiber to prepare a layered ordered self-assembled multilayer ultrathin film, which can improve the strength property of a paper sheet while endowing the paper sheet with a good antibacterial performance. Through the change of the environment and the technical conditions of an interlayer self-assembling system, multilayer film structures with different properties can be obtained on the surface of the bleached kraft hardwood fiber, the retention of an antibacterial agent on the fiber is improved, and the antibacterial effect of the paper sheet is enhanced; a layered ordered self-assembled nano-film is prepared by taking a negatively-charged fiber as a matrix and controlling the adsorption process of a reverse-phase ion system,; the preparation method is simple in production process, less in equipment investment and high in adaptability; the prepared antibacterial paper has better antibacterial performance and strength property; and antibacterial requirements of household paper and food packaging paper can be met better.