301 results about "Surface charges" patented technology

The invention relates to the technical field of water treatment equipment, in particular to an ultrasonic water treatment equipment control method and system based on variable-frequency vibration waves. According to the method, based on preset fluid working condition parameters, ultrasonic frequency conversion vibration wave signals covering multiple frequency bands are dynamically generated, and a vibrator array is driven to generate a composite sound field; a cavitation effect and an activation effect are synchronously excited in a fluid medium through variable-frequency vibration wave signals, so that physical form depolymerization and surface charge distribution change of scale forming substances occur; a shearing effect is formed on a fluid-pipe wall boundary layer, an attached state biological membrane structure is stripped, and the microscopic binding force of a crystallized scale body is loosened; monitoring the dispersion degree of scale-forming substances in the fluid and the state of a boundary layer, and adjusting the frequency band combination and energy distribution of variable-frequency vibration waves to maintain scale inhibition; and continuously optimizing the frequency conversion strategy and the sound field intensity according to the feedback data of the scale inhibition maintenance state. Through intelligent multi-band frequency conversion control of the ultrasonic water treatment equipment, efficient and environment-friendly water treatment and scale prevention effects are realized.

The invention provides high-filling silver powder and a preparation method thereof, and belongs to the field of metal powder.The preparation method comprises the steps that a nano-silver solution is prepared, a dispersing agent and a first reducing agent are mixed to obtain a mixed solution, the nano-silver solution and the mixed solution are mixed in a constant-temperature stirring state to obtain a base solution, a second reducing agent solution and a silver nitrate solution are prepared respectively, and the high-filling silver powder is prepared. And under the constant-temperature stirring state, the second reducing agent solution and the silver nitrate solution are synchronously added into the base solution, a silver powder solution is obtained through reaction, the silver powder solution is subjected to washing, solid-liquid separation, drying and depolymerization shaping treatment, and the high-filling silver powder is obtained. Controllable preparation of the large-size sphericity silver powder is achieved by controlling the particle size and the adding amount of the nano-silver, regulating and controlling heterogeneous nucleation and growth sites of silver ions and inhibiting formation of multistage dendritic crystals, surface charges and steric hindrance effects of silver particles are optimized through the surface adsorption effect of the dispersing agent, the agglomeration phenomenon of the silver powder in the growth process is reduced, and the silver powder is prepared. And meanwhile, the silver powder is endowed with excellent flowability.

The invention provides a novel environment-friendly insulating gas surface flashover characteristic evaluation method based on surface charge on-line measurement, which comprises an electric field measurement system based on an electric field induced second harmonic effect (EFISH), a coupling high-voltage surface flashover experiment system, and an evolutionary process of an electric field in a process of applying high voltage to surface flashover, the evolutionary process of charge distribution is obtained based on the electrostatic field source relation, the starting moment of surface flashover is determined by measuring sound, light and electromagnetic signals in the surface flashover process, and the starting area of the surface flashover is observed through a high-speed camera; and associating the relationship between the charge and the surface flashover, and quantitatively explaining the induction effect of the charge on the flashover.

The invention discloses a method for preparing micro-nano fibers through needle-free electrostatic spinning equipment assisted by an ion blower gun, and belongs to the technical field of spinning. The method specifically comprises the following steps: S1, dissolving a high-molecular polymer in a proper solvent to prepare a spinning precursor solution; and S2, preparing the micro-nano fiber from the spinning solution on a suitable collection surface by using an ion blower gun assisted needleless electrostatic spinning device. Through the synergistic effect of directional airflow generated by the ion blower gun and a controllable electric field, fiber surface charges are effectively neutralized, the jet instability is inhibited, and the controllability of a fiber flight path is improved. Meanwhile, the ionic wind assists in enhancing interface attachment between the fiber and the collector, uniform deposition is promoted, and the compactness and adhesive force of the fiber membrane are remarkably improved. According to the method, chemical modification does not need to be carried out on a material system, the intrinsic performance of the fiber is kept, universality and expandability are achieved, and a new path is provided for continuous preparation of the high-performance micro-nano fiber.

The invention relates to a neural network-based high-voltage live-line work safety early warning method. The method comprises the following steps of 1, establishing a high-voltage transmission line electric field calculation model by using a surface charge method; 2, establishing an overall three-dimensional model of the transformer substation; 3, constructing a signal processing circuit of the power frequency electric field sensor, capturing electric field information in real time through the power frequency electric field sensor, and converting the electric field information into a processable electric signal; 4, real-time data from the power frequency electric field sensor are received, feature extraction and classification are carried out by adopting an early warning method based on a convolutional neural network, and potential safety hazards are identified; 5, establishing a neural network-based high-voltage live working safety early warning comprehensive platform integrating data acquisition, processing, analysis and early warning; the method has the advantages that the neural network algorithm is adopted, the distance and the azimuth angle are accurately judged, live-line work is early warned, and the accident rate is greatly reduced.

The invention discloses an electrochemical biosensor of a light-driven nanopore channel and application of the electrochemical biosensor. According to the sensor, a photoresponse nanopore membrane is constructed, an outer surface aptamer probe is combined, asymmetric photothermal gradient driven ion transmission induced by near-infrared light is utilized, and ultra-sensitive detection on a target object is realized by regulating and controlling the charge density of the outer surface. According to the electrochemical biosensor provided by the invention, traditional voltage driving is replaced by asymmetric near-infrared light driving, so that the electrochemical biosensor has a relatively wide detection range and an extremely low detection limit, and high-sensitivity and specific detection on a target object can be realized. The electrochemical biosensor can be used for detecting microcystin-LR (MC-LR), the detection limit reaches 1 * 10 <-7 > mu g / L, the sensitivity is improved by 5 orders of magnitude compared with that of a traditional voltage-driven sensor, and the electrochemical biosensor can be applied to trace pollutant detection in the fields of environmental monitoring, food safety and the like.

The invention discloses a three-dimensional bio-based hierarchical pore nanocarbon water photovoltaic power generation material as well as a preparation method and application of the three-dimensional bio-based hierarchical pore nanocarbon water photovoltaic power generation material. The specific technical scheme of the preparation method comprises the following steps: firstly, preparing an acetic acid solution containing chitosan, glucose and borax, and standing the solution at room temperature for 24 hours; then, freeze-drying the precursor solution, and pre-carbonizing xerogel in a drying oven for a certain time; and finally, adding a certain amount of water into the pre-carbonized dry gel, putting the pre-carbonized dry gel into a reaction kettle with a polytetrafluoroethylene lining, reacting for a certain time at a certain temperature, dialyzing the obtained wet gel, and drying at normal temperature and normal pressure to prepare the nano carbon aerogel with the hierarchical pore structure. The nano carbon aerogel has good hydrophilicity, abundant surface charges and a hierarchical pore structure, and is a low-cost and excellent water evaporation induced power generation material.

The present disclosure relates to a process for electrostatic spray drying of a living microorganism with a specific surface charge. using electrostatic charge provided by a high voltage source, wherein said electrostatic charge is the same as the surface charge of the microorganism.

The invention specifically relates to a multi-parameter state monitoring and fault diagnosis system for an intelligent circuit breaker, and relates to the technical field of state monitoring and fault diagnosis of power equipment. A surface / bulk charge and electroluminescent optical monitoring module; a mechanical-electrical performance correlation analysis module; and a diagnosis evaluation module. According to the invention, the dielectric property micro-change module adopts a low-frequency superposition excitation and partial discharge fingerprint spectrum fusion technology, and can sensitively capture dielectric micro-change of gradual deterioration such as damp and uniform aging; the surface / body charge and electroluminescent module performs mixed optical imaging through a non-contact electrostatic potential array and PMT / APD, and accurately recognizes surface charge accumulation and early electrical tree growth; the mechanical-electrical association module quantifies thermal mechanical stress accumulation and impact vibration influence based on FBG strain monitoring and multi-physics field coupling modeling.

The invention discloses a calcium hydroxide and industrial wastewater co-treatment method, and relates to the technical field of environmental engineering, and the method comprises the following steps: S100, adopting global dynamic light scattering and electromotive force imaging combined monitoring, and monitoring surface charge change and particle size evolution of nanoparticles in industrial wastewater in a calcium hydroxide adding process in real time, and extracting a dynamic threshold index of dispersion stability mutation. According to the invention, a dispersion stability threshold is extracted through dynamic light scattering and electromotive force imaging, a particle dispersion risk index is constructed, real-time evaluation of aggregation failure of nanoparticles and dynamic prediction of a feeding strategy are realized, linkage feeding of a chelating organic polyamine flocculant is combined, bridging and surface energy mutation are blocked, and stability of charges and particle sizes is maintained. By means of closed-loop feedback and on-line early warning, the adding proportion is optimized, the gathering and settling efficiency is improved, membrane pollution and filtering blockage are reduced, and the stability and economical efficiency of wastewater treatment are improved.

The utility model belongs to the technical field of high-voltage transmission lines and insulation, and particularly relates to a three-post insulator surface charge measurement experiment device in an electrothermal composite field, which comprises an experiment cavity, a microwave heating system, a charge measurement device and a data acquisition system, the experiment chamber comprises a first experiment chamber and a second experiment chamber, the first experiment chamber is provided with a glass window, a microwave heating system is arranged above the glass window, and the three-post insulator is arranged in the second experiment chamber; a central guide rod embedded in the high-voltage guide rod on the outer side of the first experiment cavity penetrates through the first experiment cavity and penetrates through the three-post insulator, a sliding rail is arranged at the bottom of the second experiment cavity, a charge measuring device is connected to the upper portion of the sliding rail in a sliding mode, and the charge measuring device is connected with a data acquisition system. And the microwave heating system has the characteristics of small thermal inertia and easiness in instantaneous control, automatic control is conveniently realized, and the controllability of the heating process is improved.

The embodiment of the invention discloses a standard substance for simulating biological Zeta potential detection and a preparation method thereof. The method comprises the following steps: (1) preparing a 100-500nm carboxylated nano-microsphere suspension by adopting an emulsion polymerization method; (2) carrying out suction filtration on the 100-500nm carboxylated nano-microsphere suspension through a filter membrane to obtain filtrate; and (3) preparing a phosphate buffer solution with a standard concentration by using the filtrate as a solvent, adding lauryl sodium sulfate, and aging to obtain the standard substance for simulated organism Zeta potential detection. The standard substance provided by the invention can be used for calibrating and verifying a Zeta potential detection instrument, so that the detection accuracy and reliability are improved; meanwhile, the material can be used as an important tool for researching the property and function of surface charges of biomolecules, powerful support is provided for research in the fields of biomedicine and material science, and in addition, the preparation method has the advantages of being simple in process, high in repeatability and capable of simulating Zeta potentials of different biological systems and has a good application prospect.

The application relates to a preparation method of a biosensor. The application relates to a preparation method of a portable pesticide detection biosensor based on acetylcholinesterase (AChE)@poly(allylamine hydrochloride)-hydrogen bond organic framework (PAH-HOF) and application of the biosensor in on-site rapid chlorpyrifos detection, and belongs to the technical field of biosensors. According to the method, AChE is combined with poly(allylamine hydrochloride) (PAH) to change the surface charge and promote self-assembly of the AChE and the hydrogen bond organic framework (HOF), so that an AChE@PAH-HOF composite material with high catalytic activity, high embedding rate and high stability is formed; then the material is integrated into a water-retaining glycerol-sodium alginate hydrogel (G-SA) matrix to construct a disc-shaped sensor. The sensor can be attached to the surface of plants and used for long-term in-situ monitoring of organophosphorus pesticides. In combination with an image processing algorithm, the system realizes accurate tracking of the chlorpyrifos degradation process on the surface of tomato plants, and the detection limit reaches 1 ng / mL. The application provides non-invasive and low-cost technical support for crop health management and sustainable precision agriculture.

Provided is a flocculant for removing heavy metals containing a solvent and nano celluloses dispersed in the solvent. The nano celluloses may have a negative surface charge, and an average length of the nano celluloses may be about 0.2 μm to about 1 μm.

The present invention relates to a MSL membrane with enhanced osmotic energy conversion and a preparation method thereof, belonging to the field of composite material technology. SL is dissolved in water and stirred at room temperature to obtain an SL solution. A MXene nanosheet solution and EGDE are added to the SL solution and mixed. The mixture is stirred under nitrogen, centrifuged, and repeatedly washed until the supernatant reaches neutrality. The precipitate is then redispersed to obtain uniform MSL nanosheets, thereby obtaining a two-dimensional channel MSL membrane. The present invention combines SL, which has abundant functional groups, with MXene, not only addressing the water stability issues of 2D MXene but also providing a larger surface charge for selective ion transport. The ordered MXene skeleton channels provide a shorter permeation path for rapid ion transport, resulting in an MSL membrane with ultra-low resistance.

An organic electroluminescent device (OLED, organic light emitting device) comprising: an anode; a cathode, arranged opposite to the anode; and at least one light emitting layer arranged between the anode and the cathode; wherein the at least one light emitting layer comprises beside at least one emitter EM1 having a surface charge density SCDEM1, a host system comprising at least two host materials, wherein the first host material is a hole-transporting host material h-TMM having a surface charge-density SCDH1 and the second host material is an electron-transporting host material e-TMM having a surface charge-density SCDH2; characterized in that the surface charge-density of the host system SCDhost is > 0.5 mC / m2.

The application discloses an air insulation structure verification method and device based on surface flashover voltage calculation, a terminal equipment and a storage medium, and belongs to the technical field of voltage testing. The method comprises the following steps: obtaining an original structure parameter set; establishing a three-dimensional model according to the original structure parameter set; performing steady-state simulation on the three-dimensional model to obtain an initial electric field distribution; correcting the initial electric field distribution according to surface roughness to obtain a first corrected electric field distribution; performing transient simulation on the three-dimensional model to obtain a surface charge density distribution; correcting the first corrected electric field distribution according to the surface charge density distribution to obtain a second corrected electric field distribution; accumulating the volume with a second corrected electric field value not less than a preset gas critical ionization field strength to obtain a critical volume; and calculating the surface flashover voltage based on the critical volume, and verifying the original insulation structure according to the surface flashover voltage. Therefore, by implementing the application, the problem of inaccurate surface flashover voltage calculation in the prior art can be solved.

The utility model discloses a modification device for producing inorganic non-metal modified powder with good dispersity. The modification device comprises a semi-finished product bin (1), a first spiral reamer (2), an ion fan (3), a medicament barrel (4), a medicament spraying opening (5), a three-roller modification main machine (6), a cyclone separator (7), a pulse cloth bag collector (8), an induced draft fan (9), a recycled powder bin (10), a second spiral reamer (11), a packaging machine (12) and a material drying room (13). According to the device, the three-roller modification host machine is adopted to finish surface modification, so that the modification effect is good; powder modified by the three-roller modification main machine is less in agglomeration and good in dispersing performance after being separated by the air separator; the ion fan ionizes air to generate a large amount of positive and negative charges, so that charges on the surface of the powder during high-speed friction, collision and shearing can be neutralized, and the static electricity removal treatment of the powder is realized; the device can realize continuous production, and is high in yield and low in energy consumption; and the method conforms to green development, and is energy-saving and environment-friendly.

The invention relates to the technical field of high-voltage direct-current power transmission equipment, and discloses a direct-current composite insulator umbrella cover with a double-gradient structure, a preparation process and a composite insulator, the umbrella cover is of a three-layer composite structure, and the umbrella cover sequentially comprises a high-resistivity inner layer, a high-dielectric middle layer and a micro-conductive outer layer from inside to outside; the volume resistivity of the high-resistivity inner layer is larger than 1 * 10 < 13 > omega.m, and the thickness of the high-resistivity inner layer is 10%-20% of the total thickness of The volume resistivity of the high-dielectric middle layer is 1 * 10 < 10 >-1 * 10 < 12 > omega.m, the relative dielectric constant is 15-25, and the thickness of the high-dielectric middle layer is 60%-80% of the total thickness of the umbrella cover; the volume resistivity of the micro-conductive outer layer is 1 * 10 < 8 >-1 * 10 < 10 > omega.m, the relative dielectric constant is 5-8, and the thickness is 5%-20% of the total thickness of the umbrella cover. The technical problems that an existing epoxy hard composite insulator umbrella cover is uneven in electric field distribution and surface charges are prone to accumulation can be solved, and automatic regulation and control of the electric field in the insulator body and rapid discharge of the surface charges are achieved.

The present application relates to the technical field of production of coated paper, and discloses a coated paper corona treatment device, which comprises a corona device, the side of the corona device is fixed with two side plates, a plurality of guide rollers are rotationally arranged between the two side plates, an electrostatic discharge assembly is arranged between the two side plates, the electrostatic discharge assembly is composed of a wiping structure and a water storage box, the wiping structure comprises water-absorbing cloth, the water storage box accumulates water, the bottom surface of the water-absorbing cloth is immersed in the water, and a plurality of overflow holes are formed in one side of the water storage box. The coated paper treated by the corona device is wiped by the wet water-absorbing cloth, the surface charge is quickly dispersed through the micro-conductive layer formed by water molecules, meanwhile, the heterocharge is neutralized by the active adsorption of the polar molecules, the interference of static electricity accumulation on printing and compounding processes is eliminated, in addition, the dust particles adsorbed on the surface of the coated paper are physically removed by wiping, the secondary pollution caused by electrostatic adsorption is avoided, and the surface cleanliness of the product is improved.

This invention belongs to the field of microbial electrochemistry and single-cell analysis technology, and specifically relates to a femtocoulomb-level single-bacterial surface charge imaging method and its application. This technology is based on electrochemiluminescence microscopy, utilizing the spontaneous enrichment of cationic ECL luminescent molecules by the electrostatic field of the negative charge on the bacterial surface, thereby non-destructively enhancing its ECL signal. By establishing a quantitative relationship between the ECL intensity enhancement ratio and the number of adsorbed molecules, and combining this with COMSOL simulation to determine the thickness of the luminescent layer, it achieves for the first time high-throughput, high spatiotemporal resolution dynamic quantitative measurement of femtocoulomb-level charges on the surface of a single living bacterium. The invented technology has high sensitivity, high resolution, and good biocompatibility, and can be used to reveal bacterial metabolic-charge regulation mechanisms, analyze synergistic electron transport pathways, and screen highly electroactive bacterial subpopulations in situ, providing a key tool for microbial electrochemical research.

The application is specifically a multi-parameter state monitoring and fault diagnosis system for intelligent circuit breaker, and relates to the technical field of power equipment state monitoring and fault diagnosis, comprising: a dielectric property micro-change online monitoring module; a surface / body charge and electroluminescence optical monitoring module; a mechanical-electrical performance correlation analysis module; a diagnosis evaluation module.In the application, the dielectric property micro-change module adopts low-frequency superimposed excitation and partial discharge fingerprint spectrum fusion technology, which can sensitively capture the dielectric micro-change of gradual degradation such as dampness and uniform aging; the surface / body charge and electroluminescence module adopts non-contact electrostatic potential array and PMT / APD hybrid optical imaging, which can accurately identify surface charge accumulation and early growth of electrical treeing; the mechanical-electrical correlation module relies on FBG strain monitoring and multi-physical field coupling modeling, which can quantify the impact of thermal mechanical stress accumulation and impact vibration.

The application provides a method for simulating initial attachment points of lightning strikes on an airplane, which comprises the following steps: establishing a connection between a first software and a second software; presetting an initial simulation environment in the first software, calculating a first electrostatic field value of the initial simulation environment, and transmitting the first electrostatic field value to the second software; obtaining surface charges based on the first electrostatic field value by Gauss law, and judging whether a positive polarity leader is started; obtaining a negative charge quantity of the positive polarity leader according to the principle of electrostatic equilibrium; obtaining an airplane electric potential according to the negative charge quantity; setting a boundary condition according to the airplane electric potential, and calculating a second electrostatic field value; judging whether a negative polarity leader is started based on the second electrostatic field value by Gauss law, and recording a starting position if the negative polarity leader is started. The method solves the problem of dependence of a traditional method on the geometric shape and motion state of the airplane by converting the charge distribution of the leader channel into the potential boundary condition.

The invention relates to a mineral flotation method based on different-charge multi-scale bubble cooperative regulation and control, belongs to the technical field of mineral processing, and solves the problems of low mineralization efficiency and high desorption probability in a coarse particle fluidized bed flotation process in the prior art. The method comprises the following steps: step 1, system preparation; 2, starting the equipment; 3, separation is conducted, and initial collection of concentrate and tailings is completed; 4, dynamic adjustment is carried out; step 4.1, double inclination angles are cooperatively adjusted, so that the horizontal inclination angle of the strip-shaped millimeter-scale bubble production arm is kept consistent with the horizontal inclination angle of the top of the micron-scale bubble production box; and step 4.2, dynamically adjusting the ultraviolet light intensity. According to the method, the ash content data of concentrate and tailings are collected in real time through the online ash content meter, the intensity of the ultraviolet light source is dynamically adjusted, accurate regulation and control over the surface charge characteristics of the intelligent microbubbles are achieved, a'monitoring-decision-execution-feedback 'closed-loop control loop is formed, it is ensured that the flotation process is stable and reliable, and the separation efficiency of coarse-grained minerals is improved.

Methods for characterizing semiconductor doping in wide-bandgap semiconductor samples include: measuring an initial value V0 of the surface voltage at a region on the surface of the semiconductor sample in darkness; charging the region to deep depletion in darkness by depositing a specified corona charge at the region; measuring the surface voltage value at the region in darkness after charging; and using a specific photon flux f. eff The light irradiates the charging region, and a specific photon flux f eff A photon energy above the semiconductor bandgap is used, sufficient to generate free minority carriers in the semiconductor sample, thereby causing photoneutralization of the corona charge. The relationship between the photoneutralization-induced corona charge decay and the irradiation time t at the region is monitored using non-contact time-resolved measurements of the surface voltage V(t). The monitored time-resolved surface voltage decay data V(t) is analyzed to determine the photoneutralization time constant τ. ph ; and using a specific photon flux f eff Light neutralization time constant τ ph It serves as a semiconductor doping index, and its value characterizes the semiconductor doping concentration in that region.

The invention relates to the technical field of medical biological materials, and particularly discloses a composite electret flexible biological electrostatic electret patch and a preparation method thereof.The electrostatic electret patch comprises a backing layer, a medical pressure-sensitive adhesive layer and a functional layer which are sequentially arranged from outside to inside. According to the functional layer, at least one of polylactic acid, polyvinylidene fluoride and a polylactic acid-glycolic acid copolymer is selected as a polymer matrix to be compounded with graphene, a specific process combining ultrasonic dispersion and high-precision 3D printing is adopted, a deep-energy-level charge trap is introduced, the problems of high-conductivity filler agglomeration and surface charge leakage are solved, and the conductivity of the graphene is improved. The surface potential retention rate of the material can reach 60% or above after 900 days, the charge loss rate is not larger than 20% after 8-hour air exposure, and efficient physical electrostatic electret assisted sleep treatment under the drug-free and non-transdermal conditions is achieved.

The invention provides a nitrogen-rich polyimide / metal monatomic composite material and a preparation method and application thereof.The preparation method comprises the steps that firstly, a nitrogen-rich polyamide acid solution is obtained through a chemical polymerization method, a carrier material is coated with the nitrogen-rich polyamide acid solution, gradient heating thermal imidization is conducted, and the nitrogen-rich polyimide / carrier composite material is obtained; and anchoring a metal single atom on the nitrogen-rich polyimide / carrier composite material by an impregnation method to finally obtain the nitrogen-rich polyimide / metal single atom composite material coated on the carrier material. Nitrogen atoms and oxygen atoms on the prepared nitrogen-rich polyimide / metal monatomic composite material can provide stable metal monatomic anchoring sites; meanwhile, the nitrogen-rich structure with strong electron deficiency is beneficial to promoting charge accumulation on the surface of the material and improving the concentration of local reactants near metal active sites, so that the stability and catalytic activity of the material are remarkably improved.

The application discloses an ionic liquid-metal organic framework composite material and a preparation method and application thereof, and particularly relates to the technical field of air purification membrane materials. The ionic liquid-metal organic framework composite material provided by the application realizes efficient capture of particulate pollutants (PM) in air through the action of surface charges and / or polar functional groups of MOF and the strong electrostatic action of IL with high static potential. The fiber membrane loaded with the ionic liquid-metal organic framework composite material provided by the application can capture pollutants with small particle sizes in air by means of the electrostatic force of the ionic liquid-metal organic framework composite material to attract and polarize the pollutants, so that the capture efficiency of PM and other particles in air can reach more than 98%, and the performance is almost unchanged after 96 hours of use, and the ionic liquid-metal organic framework composite material has excellent long-term durability. 2.5 ​

The invention belongs to the technical field of pollution control of membrane method water treatment, and particularly relates to a composite conductive membrane, a preparation method thereof and application of the composite conductive membrane in membrane pollution control and N2O emission reduction. According to the composite conductive film, polyvinylidene fluoride serves as a matrix, nano titanium dioxide is introduced to improve the hydrophilicity and surface charge characteristics of the film, nano silver modified carbon cloth is adopted to construct a conductive layer, and the conductive layer and a separation layer are integrally combined through a phase inversion method. When the membrane operates under the condition of external low voltage, adsorption and deposition of pollutants on the surface of the membrane are inhibited through the surface charge conduction effect, meanwhile, the denitrification electron transfer process is promoted, and the synergistic effect of membrane pollution control and greenhouse gas emission reduction is achieved. The prepared composite conductive film is stable in structure, high in hydrophilicity and excellent in conductivity, is suitable for the field of municipal sewage, industrial wastewater and sludge treatment, and has remarkable energy-saving and environmental benefits.

To provide a process for producing cationic colloidal silica which is surface-modified by at least one aminoalkoxysilane having an amino group in a cationic form.SOLUTION: The production method comprises (i) reacting, under alkaline conditions, negatively charged colloidal silica with at least one aminoalkoxysilane having an amino group in a cationic form at above 20°C to produce surface-modified colloidal silica having a net negative surface charge, and (ii) reversing the surface charge of the net negatively charged surface-modified colloidal silica by contacting the net negatively charged surface-modified colloidal silica with an ion exchange resin to obtain positively charged surface-modified colloidal silica.SELECTED DRAWING: Figure 1