76 results about "Poly(N-isopropylacrylamide)" patented technology

The present invention relates to a method and a wood preserving composition which comprises mixtures of a metal compound, complexing agents selected from ethanolamines, polyethylenimine, ammonia or a mixture of these compounds, and a vinyl based polymer selected from poly(vinyl alcohol) (PVA), poly(acrylamide) (PA), poly(N-vinyl pyrrolidone) (PVP) and poly(N-isopropyl acrylamide) (PNIPAM). The resulting metal amine solution can then be used to formulate a variety of metal-based cellulosic material preserving products.

The invention discloses a carbon quantum dot-poly N-isopropylacrylamide composite material and a preparation method thereof. An N-isopropylacrylamide polymer is grafted to the surface of carbon quantum dots obtained by microwave treatment by adopting an atom transfer radical polymerization (ATPR) method. The preparation method is simple, convenient and mild in conditions. Modified carbon nano particles have fluorescence property and temperature sensitivity.

Lipobeads (liposome-encapsulated hydrogels) combine properties of hydrogels and liposomes to create systems that are sensitive to environmental conditions and respond to changes in those conditions in a fast time scale. Lipobeads may be produced by polymerizing anchored or unanchored hydrogels within liposomes or by mixing anchored or unanchored hydrogels with liposomes. Giant lipobeads may be produced by shrinking unanchored nanogels in lipobeads and fusing the resulting lipobead aggregates, long-term aging of anchored or unanchored lipobeads, or mixing anchored or unanchored aggregated nanogels with liposomes. Poly(acrylamide), poly(N-isopropylacrylamide), and poly(N-isopropylacrylamide-co-1-vinylimidazole) lipobeads were produced and characterized.

The invention relates to a thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane and a preparation method thereof, relating to a medicine-loading electro-spun fibrous membrane and a preparation method thereof and aiming to solve problems of poor mechanical property of existing poly N-isopropylacrylamide medicine-loading electro-spun fibrous membrane and no temperature sensitivity of a polyurethane medicine-loading electro-spun fibrous membrane. The thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane is prepared by poly N-isopropylacrylamide, polyurethane, N,N-dimethylformamide and a medicine; the preparation method comprises the following steps: 1, preparing static spinning solution; 2, dissolving the medicine so as to obtain the static spinning solution containing the medicine; 3, carrying out electrospinning; and 4, carrying out dry treatment to obtain the thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane. According to the invention, the preparation method is mainly used for preparing the thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane.

The invention discloses a two-block copolymer of poly-N-isopropyl acrylamide-polyamino acid and making method, which is characterized by the following: the number average molecular weight of poly-N-isopropyl acrylamide-polyamino acid is 1000-10000; the polyamino acid is poly-L-glutamic acid or poly-L-aspartic acid with number average molecular weight at 1000-30000; the molar percentage of amino acid carbobenzoxy is 0-90%; the invention uses hydrogen bromide or reducing method to strip benzyl through catalyzing and hydrogenating to obtain the product, which possesses double response for temperature and pH value in the solution; the copolymer can be biological decomposed to be discharged out of body through kidney directly, which can be carrier of target drug release and injectable intellectual response aquagel.

A novel method of preparation of easily stripped off temporary wound dressing material is disclosed. In this process, the-N-isopropyl acrylamide (NIPAAm) monomer is successfully grafted on the non-woven cloths by copolymerization. It is initiated by gamma -ray irradiation to activate the surface of the non-woven cloth. NIPAAm is then grafted onto the surface of the non-woven cloth. The free radical or peroxide is produced by Co-60 gamma -ray, then grafted on the non-woven cloths. The lower critical solution temperature (LCST) in thermoresponsive poly-N-isopropylacrylamide (NIPAAm) is still retained after the grafting. This will make the dressing cloth stripped off easily and without hurting the tissue. The material process is very simple and has medically applicable value.

The invention relates to a nucleic acid chip and a preparation method and application thereof, belonging to the detection field of enzymes, microorganisms or nucleic acid molecules. The nucleic acid chip comprises a substrate, nucleic acid molecules are attached to a part of the surface of the substrate; a region of the substrate without the nucleic acid molecules is covered with a material capable of inhibiting cell growth; the material can be a non-biocompatible material, such as poly-N-isopropylacrylamide, polyvinyl caprolactam, polyacrylic acid, chitosan, sodium alginate, and the like or be DNA, siRNA, esiRNA, plasmid, and the like. The nucleic acid chip is particularly suitable for researching functional gene screening aspects, such as cell proliferation, cell differentiation, apoptosis, cell migration, and the like.

The invention discloses a preparation method for a monodisperse hollow silicon dioxide nanosphere with the controllable size and shell thickness. The preparation method comprises the following steps of: preparing poly-N-isopropylacrylamide by polymerizing an N-isopropylacrylamide monomer with soap-free emulsion under an oxygen-free condition at 60-80 DEG C; after mixing the prepared poly-N-isopropylacrylamide emulsion with prehydrolysis solution of tetraethoxysilane at 40-60 DEG C, carrying out a thermostatic reaction for 48-96 hours, and obtaining the monodisperse hollow silicon dioxide nanosphere after separating and calcining. The preparation method is simple and controllable, and the water is taken as the solvent in each reaction, so that the preparation method is green and environment-friendly; the obtained hollow silicon dioxide nanosphere is of a monodisperse structure, the size is 100-500 nm, the shell thickness is 30-100 nm, and the size and the thickness are both controllable, so that the method can be widely applied to the fields of medical controllable slow release, catalysis, microcapsules and the like.

The invention relates to a method for adsorbing uranium by using macroporous poly-N-isopropylacrylamide/chitosan semi-interpenetrating network temperature-sensitive hydrogel. The method comprises the following steps: by utilizing emulsion polymerization means, taking Span-80 as an emulsifier, taking N,N'-methylene bisacrylamide (MBA) as a cross-linking agent, taking ammonium persulfate (APS) as an initiator, and taking N,N,N',N'-tetramethylethylenediamine (TEMED) as an accelerant, preparing the macroporous poly-N-isopropylacrylamide/chitosan semi-interpenetrating network temperature-sensitive hydrogel under certain conditions, and researching and measuring the adsorption performance of the hydrogel on uranium. Compared with the traditional gel and pore-free gel, the hydrogel disclosed by the invention has the characteristics of high mechanical strength, good swelling properties, large adsorption surface area, controllable adsorption and desorption processes, high uranium adsorption quantity and the like.

The invention discloses an SERS (surface enhanced Raman scattering) device, as well as a preparing method and application thereof. The device comprises a capillary tube with a mixing colloid and an active substrate both arranged therein, wherein the mixing colloid consists of poly-(N-isopropyl acrylamide), gold nanorods and water with the weight ratio of (1.8-2.2):(0.001-0.003):(100); the active substrate adopts the structure that tapered zinc oxide nanorods with silver nanoparticles modified surfaces are stood on the surface of a heating wire. The method includes the following steps: adding ammonia water in a zinc nitrate hexahydrate solution, and obtaining an electric precipitating solution after the ammonia water is completely dissolved; using the heating wire as a cathode and placing the heating wire in the solution for electric precipitation, so as to obtain the heating wire with tapered nanorods stood on the surface; then immersing the heating wire with the tapered nanorods stood on the surface in a silver nitrate solution and irradiating the heating wire by ultraviolet light, so as to obtain an active substrate; then placing the active substrate and the mixing colloid in the capillary tube, so as to prepare the target product. According to the invention, the SERS device can be widely applied in real-time detection of pollutants in water solutions in environmental, chemical, biological fields and the like.

The invention provides a multiple-response type self-repair hydrogel material and a preparation method and application thereof. The multiple-response type self-repair hydrogel material is prepared from polydopamine methacrylate-N-isopropylacrylamide, poly-N-isopropylacrylamide-4-vinyl benzeneboronic acid and water. The multiple-response type self-repair hydrogel material has the characteristics that the effects of pH (potential of hydrogen) response and temperature response are realized, the self-repair property is realized, and the application prospect is broad in the fields of biomedical materials, nanometer materials and photoelectric materials.

The present invention relates to a process for preparing copolymer hydrogels with controlled molecular weights and having both thermo- and pH-responsive properties, wherein the process comprises the steps of (a) providing sulfonamide type styrenic or (meth)acrylamide-based monomers exhibiting different pKa values; (b) providing poly(N-isopropylacrylamide) or crosslinked poly(N-isopropylacrylamide-co-methylene bisacrylamide) hydrogels having thermo-responsive properties; and (c) providing several hydrogels exhibiting pH-sensitive properties and random or block copolymerizations of the sulfonamide type styrenic or (meth)acrylamide-based monomers prepared in step (a) with N-isopropylacrylamide and/or methylene bisacrylamide monomers used in step (b) in a polar or non-polar solvent; wherein said steps (b) and (c) are carried out by controlled/living radical polymerization using alkyl halides as the initiators and the transition metals with phosphine or amine ligands as the catalysts. The present invention also relates to the copolymer hydrogels made by the aforesaid process.

A device for collecting water from atmospheric moisture comprises water absorbing material, a protection wall and a water container. The protection wall is in a porous form. The water absorbing material is made of the temperature responsive polymer with a phase separation temperature, including Poly(N-isopropylacrylamide) (PNIPAM), Poly(vinylphosphonate) and etc. when its temperature is below phase separation temperature, the temperature responsive polymer is in a swollen hydrated state, forming hydrogen bond with water molecules; so as to absorb water from the air. When its temperature is above said phase separation temperature, the temperature responsive polymer is in a shrunken dehydrated state, forming hydrogen bond with other temperature responsive polymer molecules; so as to expel the water to the water container.

The invention provides a hydrogel-solid amphiphilic particle for emulsion stabilization. The hydrogel-solid amphiphilic particles are gel microspheres composed of network gel hemispheres obtained fromcalcium ion crosslinked sodium alginate and chemically crosslinked polymer network hemispheres having thermosensitivity, and have hydrophilic and hydrophobic high anisotropy. The preparation method of the hydrogel-solid amphiphilic particles comprises the following steps: dissolving sodium alginate, a calcium salt, a crosslinking agent and a thermosensitive polymer into water to serve as an aqueous phase; preparing an oil phase containing a nonionic surfactant; mixing the aqueous phase and the oil phase, and sharply stirring to prepare monodispersed emulsion; performing solvent replacement toremove the surfactant; raising the temperature of the emulsion, precipitating poly-N-isopropylacrylamide from the gel, forming hydrogel hemispheres from the sodium alginate and calcium ions, and forming the hydrogel-solid amphiphilic particle. The hydrogel-solid amphiphilic particle has an effect of stabilizing the emulsion at a high temperature of higher than 37 DEG C, so that the emulsion can be stored for a long time at the high temperature.

The invention relates to a composite material film containing a poly N-isopropylacrylamide component and a preparation method thereof. A film forming material of the composite film is poly N-isopropylacrylamide and chitosan components, wherein the mass content of the chitosan components is from 10% to 70%, and the balance of the poly N-isopropylacrylamide components. The preparation method comprises the steps of: fully mixing a solution containing the poly N-isopropylacrylamide (PNIPAAm) with the proportion ratio and a cross-linking chitosan solution for reaction under stirring; paving and drying the reactants; neutralizing the reactants by an alkaline solution until the pH of the solution is from 6 to 7; and cleaning by water to remove impurities and obtain the composite material film product. The composite material film has good thermosensitivity and uniform film forming property, improves the property of poor mechanical performance under a swelling state of the PNIPAAm (poly N-isopropylacrylamide), greatly widens the application range, and has more convenient application in the aspects of drug slow release, material separation and purification as well as medical materials. The preparation method is simple and convenient.

The invention relates to novel pH sensitive type hydrogel and a preparation method and an application thereof. According to the hydrogel, selected pH response main polymer monomer raw materials of carboxymethyl chitosan and itaconic acid both come from natural product chemical compounds and are water-based environmentally friendly and good in biocompatibility; the polyvinyl modified carboxymethylchitosan and polyitaconic acid in the hydrogel are subjected to carboxyl ionization at a high pH value, meanwhile the polyvinyl modified carboxymethyl chitosan and poly N-isopropylacrylamide are subjected to amino absorption hydrogen ion ionization at a low pH value, and due to existence of different polymer units, the hydrogel has pH sensitivity. The hydrogel has higher swelling ratio at relatively mild pH and has low swelling ratio at relatively drastic pH so that the hydrogel can be used for drug release, achieves effectiveness of drug administration through the gastrointestinal tract and has wide application prospects.

The invention discloses modified thermo-sensitive NIPAM bentonite. NIPAM molecules are firmly adsorbed on montmorillonite minerals, and are inserted between bentonite mineral layers or adsorbed on thesurfaces of bentonite particles, and the bentonite particles responds to the temperature. A preparation method of the modified thermo-sensitive NIPAM bentonite comprises the following steps: pre-hydrating bentonite, adding an N-isopropyl acrylamide (NIPAM) crystal or low molecular weight poly N-isopropylacrylamide, performing constant-temperature magnetic stirring, sufficiently reacting NIPAM with hydrated clay to obtain a mixed solution, removing NIPAM molecules not adsorbed on the surface of the bentonite, and drying and crushing to prepare the modified thermo-sensitive NIPAM bentonite. Theinvention further discloses a temperature response type drilling fluid, which is prepared from the modified thermo-sensitive NIPAM bentonite, Lv-PAC, CMC, CaCO3 and water. The modified thermo-sensitive NIPAM bentonite can enhance the plugging property of a mud cake under the formation condition, reduce the filter loss of the drilling fluid, and improve the high temperature stability of drilling fluid rheology. The temperature response type drilling fluid has temperature responsibility, and has certain self repairing ability, and under a high temperature condition, the temperature response type drilling fluid has relatively high stability.