482 results about "Cellulose nanocrystals" patented technology

The invention provides a method for preparing fibrilia carboxylation cellulose nanowhiskers, which is characterized by comprising the following steps: soaking fibrilia powder in sodium hydroxide for processing, then processing the fibrilia powder by a former treating agent and taking out the fibrilia powder to be dried in a vacuum oven to obtain preprocessed fibrilia powder; and placing the preprocessed fibrilia powder in a TEMPO oxidation system for catalytic oxidation to obtain a stable cellulose nanowhiskers suspending liquid after mechanical processing and freeze drying the suspending liquid to obtain the fibrilia carboxylation cellulose nanowhiskers having grain diameters of 3-10 nm. According to the invention, fibrilia carboxylation and nano fibrillation are realized and surfaces of prepared nanocrystalline celluloses have carboxyl functional groups, thus the surfaces generate negative charges, electrostatic repulsion among the negative charges can avoid the reunion of nanoparticles, so that the nanocrystalline celluloses can be well dispersed in water and the obtained nanocrystalline celluloses have excellent uniformity of grain sizes.

The invention provides a method for preparing a cellulose nanocrystal/electrostatic spinning nanofiber filter film. The method is characterized in that the prepared cellulose nanocrystals of which the diameter is 3 to 10nm are coated on the surface of an electrostatic spinning nanofiber film to form a network structure so as to filter out impurities in raw water, intercept suspended solids, colloid, bacteria and the like in the water and effectively adsorb residual chlorine and heavy metal in the water; and therefore, the aim of purifying water quality can be fulfilled. Moreover, due to the adoption of a multi-layer compounded mode, the mechanical strength of the nano fiber film can be improved by the cellulose nanocrystals, so that the filter film has the advantages of simple structure, high mechanical strength, good filtering effect, low cost and the like, and has wide application prospect in the fields of drinking water purification, textile dyeing wastewater treatment, polyvinyl acetate (PVA) slurry recycling and the like.

The invention relates to a preparation method of nanometer zinc oxide-bamboo charcoal composite particle with antibacterial and adsorption functions. The preparation method comprises the following steps: (1) adding a bamboo raw material into a mixed acid solution, reacting at 50-90 DEG C for 1-20 hours, adding alkali liquor to neutralize the solution after the reaction to obtain a carboxylated bamboo cellulose nanocrystals; (2) adding the carboxylated bamboo cellulose nanocrystals into a solution of 0.005-5 mol/L zinc ions, adding alkali liquor to neutralize, diluting the reaction product through deionized water, centrifuging and freeze drying or vacuum drying the reaction product, and then, vacuum calcining the reaction product at 200-600 DEG C for 1-8 hours to obtain the nanometer zinc oxide-bamboo charcoal composite particle. The process disclosed by the invention is simple, convenient, easy to operate and free of environmental pollution, and the preparation period of the composite particle is shortened; the prepared nanometer zinc oxide-bamboo charcoal composite particle is small in size, easy to regulate and control and large in specific surface area, the bamboo charcoal is very firmly combined with the nanometer zinc oxide, so that the antibacterial effect is durable, and the nanometer zinc oxide-bamboo charcoal composite particle has good adsorption capacity on toxic substance, thereby having a wide application prospect.

A composition comprising nanocellulose is disclosed, wherein the nanocellulose contains very low or essentially no sulfur content. The nanocellulose may be in the form of cellulose nanocrystals, cellulose nanofibrils, or both. The nanocellulose is characterized by a crystallinity of at least 80%, an onset of thermal decomposition of 300° F. or higher, and a low light transmittance over the range 400-700 nm. Other variations provide a composition comprising lignin-coated hydrophobic nanocellulose, wherein the nanocellulose contains very low or essentially no sulfur content. Some variations provide a composition comprising nanocellulose, wherein the nanocellulose contains about 0.1 wt % equivalent sulfur content, or less, as SO₄ groups chemically or physically bound to the nanocellulose. In some embodiments, the nanocellulose contains essentially no hydrogen atoms (apart from hydrogen structurally contained in nanocellulose itself) bound to the nanocellulose. Various compositions, materials, and products may incorporate the nanocellulose compositions disclosed herein.

Recyclable organic solar cells are disclosed herein. Systems and methods are further disclosed for producing, improving performance, and for recycling the solar cells. In certain example embodiments, the recyclable organic solar cells disclosed herein include: a first electrode; a second electrode; a photoactive layer disposed between the first electrode and the second electrode; an interlayer comprising a Lewis basic oligomer or polymer disposed between the photoactive layer and at least a portion of the first electrode or the second electrode; and a substrate disposed adjacent to the first electrode or the second electrode. The interlayer reduces the work function associated with the first or second electrode. In certain example embodiments, the substrate comprises cellulose nanocrystals that can be recycled. In certain example embodiments, one or more of the first electrode, the photoactive layer, and the second electrode may be applied by a film transfer lamination method.

The invention discloses a method for preparing a super-hydrophobic coating with a nanocrystalline cellulose/silicon dioxide (NCC/SiO2) composite template process. The method comprises the following steps: (1) treating microcrystalline cellulose (MCC) with 56% sulfuric acid; (2) performing centrifugal washing; (3) replacing water in an NCC suspension solution with ethanol; (4) grinding for later use; and (5) freezing a sample to subzero 30 DEG C and performing vacuum freeze-drying. The method has the advantages that stearic acid is taken as a modifier and can produce a dehydration reaction with surface -OH of SiO2/NCC, and stearic acid further introduces hydrophobic -CH3 groups, so that the surface energy of SiO2/NCC is reduced; and an NCC and SiO2 compound has not only the properties of a biopolymer material but also the properties of an inorganic material such as weather resistance, hardness and the like, can be used for modifying indoor and outdoor coatings, and can play a role in aspects of building floor cleaning, furniture pollution prevention and the like.

The invention discloses a method for sustainably preparing nanometer cellulose in an environment-friendly and economic mode. The preparing method includes the following steps that 1, cellulose raw materials and organic acid are hydrolyzed and esterified; 2, the treated cellulose is prewashed in a centrifugal sedimentation mode, the organic acid is separated to be continuously recycled, washed cellulose suspension liquid is dialyzed, and then reacted acid and accessory substances are removed; 3, the dialyzed suspension liquid is separated to obtain small-particle cellulose nanometer crystals; 4, cellulose solid precipitated on a lower layer of the suspension liquid is treated through a high-pressure homogenizer or an ultrasonication physical machine to obtain colloidal cellulose nanometer fibrils. According to the method, in the preparing process, the modified cellulose raw materials are synchronously hydrolyzed and esterified through relative-safety and environment-friendly food-grade organic acid; compared with inorganic strong acid, the used organic acid is low in corrosion performance, high in boiling point, small in reaction pressure and easy to control and operate, and the cellulose nanometer crystals with the stable quality and the cellulose nanometer fibril products with the stable quality can be obtained at the same time.

The invention discloses a preparation method and an application of a cellulose nanocrystals (CNCs)-reinforced collagen compound substrate, which belong to the field of tissue engineering. The preparation method comprises the following steps of: preparing CNCs by adopting a method for degrading cellulose with sulfuric acid; preparing a CNCs solution and a collagen solution, and mixing the CNCs solution and the collagen solution physically; and pouring the mixed solution into a mold, and molding to obtain the CNCs-reinforced collagen compound substrate. According to the CNCs-reinforced collagen compound substrate prepared with the method, the problems of poor mechanical strength and poor hydrophilicity of the conventional collagen material are solved; and the CNCs-reinforced collagen compound substrate can be applied in the fields of wound dressings, tissue inducing regeneration membranes, soft tissue patches, tissue engineering skin, facial masks and the like. A preparation process technic provided by the invention is easy and practicable, has high repeatability, and is suitable for industrial production of CNCs-reinforced collagen compound substrates of different requirements.

The invention relates to a preparation method of a composite material with the fiber surface coated with cellulose nanocrystals and used for multi-scale enhancement. By adoption of the preparation method, the technical problems of poor macro-mechanical properties, low preparation efficiency and high cost of an existing fiber composite material are solved. The preparation method comprises the following steps: (1) putting the cellulose nanocrystals and deionized water in a device for mechanical stirring, carrying out ultrasonic dispersion and obtaining a sizing solution; (2) fixing unsized continuous fiber on a traction machine, and removing water by an impregnating vessel filled with the sizing solution and then winding for standby application; (3) preparing the obtained continuous fiber with the surface coated with the cellulose nanocrystals into a composite material strip sample, and curing according to the curing procedures of a selected resin system and obtaining the fiber-enhanced composite material coated with the cellulose nanocrystals. The preparation method can be widely used in the field of preparation of the composite material.

The invention discloses crease-resistant finishing liquid for cotton fabric and application of the crease-resistant finishing liquid and belongs to textile finishing. The crease-resistant finishing liquid is characterized in that a laccase/TEMPO system is used to oxidize cellulose nanocrystals into aldehyde groups, the aldehyde groups and Girard's reagent T have Schiff base reaction to prepare positive ion modified cellulose nanocrystals, and the modified cellulose nanocrystals, 1,2,3,4-butanetetracarboxylic acid and chitosan are compounded to apply to the crease-resistant finishing of the cotton fabric. The crease-resistant finishing liquid has the advantages that the chitosan and the cellulose nanocrystals used by the finishing liquid are natural biomass materials and can copolymerize with BTCA on cotton fibers under high temperature to generate a long branched chain structure, and accordingly the cotton fabric after finishing has good crease resistance; in addition, by introducing the cellulose nanocrystals and the chitosan, the break strength retention and dyeing performance of the fabric after the crease-resistant finishing are improved, and the fabric is good in washing resistance stability and meets environment protection standards.

Natural biopolymers in the form of cellulose nanocrystals (CNC) are shown to have the required characteristics to serve as chemically reactive biotemplates for metallic and semiconductor nanomaterial synthesis. Silver (Ag), gold (Au), copper (Cu) and platinum (Pt), cadmium sulfide (CdS), zinc sulfide (ZnS) and lead sulfide (PbS) nanoparticles, nanoparticle chains and nanowires may be synthesized on CNCs by exposing metallic precursor salts to a cationic surfactant, cetyltrimethylammonium bromide (CTAB), and a reducing agent. The nanoparticle density and particle size may be controlled by varying the concentration of CTAB, pH of the salt solution, as well as the reduction time or reaction time between the reducing agent and the metal precursor.

The invention discloses a preparation method of a cellulose nanocrystal and chitosan composite membrane, and belongs to the field of modification of natural polymers. The method comprises the steps that cellulose nanocrystal (CNC) sol is prepared by conducting concentrated sulfuric acid hydrolysis on microcrystalline cellulose; the cellulose nanocrystal (CNC) sol is reacted with sodium periodate to prepare dialdehyde cellulose nanocrystal (DAC) sol and the cellulose nanocrystal (CNC) sol is reacted with a Girard's reagent T to prepare cationic cellulose nanocrystal (CDAC) sol. The CDAC sol is directly mixed with a chitosan-acetic acid solution, vacuum defoamation tape casting is conducted in a polytetrafluoroethylene mold, drying at room temperature is conducted, and the membrane is obtained. Compared with a pure chitosan membrane, the mechanical property of the prepared cellulose nanocrystal and chitosan composite membrane can be obviously improved, and the swelling degree in water is obviously reduced.

The invention relates to a preparation method of cellulose nanocrystal/graphene/polyvinyl alcohol ternary composite enhanced aerogel. The preparation method comprises 1) preparation of cellulose nanocrystals, 2) preparation of a cellulose nanocrystal/graphene mixed solution, 3) preparation of a cellulose nanocrystal/graphene/polyvinyl alcohol ternary composite solution, 4) inorganic salt induction, 5) alcohol solution replacement, and 6) freeze drying. Through reasonable adjustment of the ratio of cellulose nanocrystals, graphene to polyvinyl alcohol, the aerogel with better performances is prepared. The aerogel has a large specific surface area, a small pore size, low density and good adsorptivity. The graphene oxide sheet improves the mechanical properties of the aerogel. The polyvinyl alcohol improves the biocompatibility and degradability of the product. The spherical aerogel has a large effective adsorption area and high adsorption efficiency. The resource utilization of gas and solid wastes and the water environment control and treatment are effectively combined so that the circular economy is promoted.

The present invention relates to a composition in the form of an emulsion, advantageously a Pickering emulsion, comprising a hydrophobic phase dispersed in an aqueous phase, which composition contains emulsifying particles capable of stabilizing said emulsion, at least some of said particles consisting of cellulose nanocrystals having an elongated shape, which have the following features: a length between 25 nm to 1 μm, and a width between 5 to 30 nm.

The present disclosure relates to use of polydopamine (PD) coated cellulose nanocrystals (CNCs) as template for further conjugation of functional oligomers (amines, carboxylic acids etc.) and the immobilization of various types of CNC hybrid nanomaterial nanoparticles to improve their stability in aqueous solution, e.g. the preparation of silver nanoparticle on CNC. Surface functionalization of CNC with polydopamine can be performed by mixing dopamine and CNCs for certain time at designed temperature. The resultant PD-CNCs can be used to stabilize metallic and inorganic nanoparticles, which could be generated in-situ, and further immobilized on the surface of PD coated CNCs. Benefiting from the improved stability, the resultant nanoparticles immobilized PD-CNC system also generally possess higher catalytic activity than the nanoparticles alone.

The invention relates to a method for preparing cellulose nanocrystal reinforced polyhydroxybutyrate-hydroxyvalerate (PHBV) nanofiber. The method comprises the following steps of: (1), adding an organic solvent, namely a solution A, of cellulose nanocrystals (CNCs) into an organic solvent, namely a solution B, of a PHBV during stirring to obtain a mixed solution; (2), heating the mixed solution to 40 to 70 DEG C, fully stirring to obtain a transparent and uniform electrostatic spinning stock solution; and (3), performing electrostatic spinning on the stock solution, performing vacuum drying on the stock solution at room temperature to obtain the PHBV or CNCs. The method is simple, controllable, quick and efficient. The prepared PHBV or CNCs is or are a complete biodegradation product, has high biodegradability and biocompatibility, high porosity, adjustable aperture and tailorable shapes, and has the advantages of high mechanical property, high thermal property, appropriate hydrophilcity and the like.

The invention relates to a method for preparing biodegradable solid-solid phase transition nano fibers or fiber membranes, which comprises: (1) adding a coupling agent and a catalyst into water dispersion of cellulose nanocrystals in turn, dripping dehydrant-containing ethanol solution, stirring, reacting for 6 to 10 hours to prepare water dispersion of carboxyl cellulose nanocrystals; (2) adding PEG and a catalyst into the water dispersion of carboxyl cellulose nanocrystals in turn, dripping the dehydrant-containing ethanol solution, stirring and reacting for 10 to 12 hours to obtain polyethylene glycol grafted cellulose nanocrystal graft copolymer; and (3) preparing aqueous solution of the graft copolymer as spinning solution and spinning. In the invention, the cost is low, the whole preparation process is performed in a water system, the preparation process is simple, easy to control and suitable for industrial production; and the obtained biodegradable solid-solid phase transition nano fibers or fiber membranes have the advantages of high storage capacity and proper phase transition temperature and the like.

The invention provides a preparation method of a zinc oxide and cellulose nanocrystal composite super-hydrophobic coating. The reparation method of the zinc oxide and cellulose nanocrystal composite super-hydrophobic coating is characterized by comprising the following steps that 1, nano zinc oxide with special morphology and a cellulose nanocrystal solution are mixed according to a certain proportion and added into a mixed solution of stearic acid and ethyl alcohol under the condition of magnetic stirring; 2, the mixture is taken out after a certain time and aged, dried and ground into powder, the powder is added into a mixed solution of deionized water, a catalyst ammonia water and a dispersing agent sodium dodecyl benzene sulfonate, and magnetic stirring is conducted after ultrasound is conducted till the mixture is a thick state; 3, a certain amount of polydimethylsiloxane and silane coupling agent are added for continuous magnetic stirring, and a solution is formed and coated on the base material surface to form the super-hydrophobic coating. The preparation method of the zinc oxide and cellulose nanocrystal composite super-hydrophobic coating has the advantages that the preparation technology is simple and easy to operate, the super-hydrophobic coating is suitable for being added into various coatings, and the properties of hydrophobicity, sterilization and abrasion resistance enhancing are achieved.

This invention provides a process for producing a nanocellulose-lignin material, comprising: providing a starting material comprising lignin and discrete cellulose fiber fines, chemically and physically separate from the lignin; and mechanically refining the starting material to form a nanocellulose-lignin material comprising cellulose nanofibrils and/or cellulose nanocrystals chemically or physically associated with the lignin. In certain embodiments, the starting material contains about 60 wt % lignin and about 40 wt % cellulose fiber fines on a dry basis. The starting material may be obtained from an AVAP® process. The refining may utilize single disk refiners, double disk refiners, conical refiners, cylindrical refiners, beaters, grinders, homogenizers, microfluidizers, vortex mixers, rotor-stator mixers, and/or high-shear mixers, for example. A novel nanocellulose-lignin composite material is obtained.