64 results about "Metal chelation" patented technology

The invention relates to the technical field of biological separation materials, and discloses an amine-functionalized magnetic nano composite material and application thereof in protein separation and purification. The material has a core-shell structure and comprises a magnetic ferroferric oxide nano core, an ordered mesoporous silicon dioxide intermediate layer and a covalent grafted polyethyleneimine functional layer. By controlling the matching relationship between the pore diameter of mesopores and the molecular size of the polymer and adopting a crosslinking strategy, the material has high magnetic responsiveness, rapid mass transfer performance and high-density surface amino groups. The material shows high adsorption capacity, rapid adsorption kinetics and good cycle stability in the protein separation process, and is suitable for enrichment purification and metal chelating affinity separation of protein in a biological sample. According to the invention, the technical problems of low protein adsorption capacity, slow dynamics and poor cycling stability caused by compact shell layer, non-uniform amino distribution and limited mass transfer of the existing amine functionalized magnetic material are solved.

The invention relates to the technical field of industrial flue gas purification, in particular to a desulfurization and denitrification integrated flue gas purification system and method.The desulfurization and denitrification integrated flue gas purification system comprises an integrated washing tower, and the washing tower sequentially comprises an atomization venturi section, a desulfurization section, a denitrification section, a desulfurization section and a denitrification section which are communicated in the flue gas flowing direction, and the atomization venturi section is used for conducting preliminary acceleration, cooling and dust particle pre-wetting on introduced flue gas; the rotational flow centrifugal section is used for enabling the flue gas and the washing liquid to generate strong rotary centrifugal motion so as to realize gas-liquid-solid primary separation and mass transfer; the boiling foam absorption section is used for enabling the washing liquid at the bottom of the tower to form a boiling foam layer through an air distribution device and flue gas with a specific flow speed so as to provide a huge gas-liquid contact area; the dehydrating and demisting section is used for separating liquid drops entrained in the purified flue gas; by skillfully combining NO trapping by metal chelating and wet desulfurization by calcium, alkali and method, the method is realized in a unique boiling centrifugal tower, dust removal, desulfurization and denitrification are synchronously and efficiently completed in one tower body, the system is compact, and the investment and operation cost is low.

The invention belongs to the field of solar interface evaporation materials, and discloses a natural polyphenol-based hydrogel for metal wastewater treatment and a preparation method and application thereof.The preparation method comprises the steps that a solution containing natural polyphenol and a solution containing oxidized polysaccharide are mixed according to the mass ratio of the natural polyphenol to the oxidized polysaccharide being 1: (1-3) and then react for 6-36 h at the temperature of 50-70 DEG C, and the natural polyphenol-based hydrogel is obtained. The hydrogel is obtained. According to the preparation method, natural polyphenol and oxidized polysaccharide are copolymerized, the bulk hydrogel is synthesized in one step under the alkaline heating condition, the metal chelating capacity of the natural polyphenol is further utilized, metal ions in wastewater can be effectively extracted, and the photo-thermal capacity of the hydrogel is enhanced; the finally obtained hydrogel can fully utilize light energy in a full wavelength range of an ultraviolet-visible light-infrared region to be converted into heat energy, and has a huge application prospect in the field of wastewater treatment.

The application discloses a demetallization agent, a preparation method and application method thereof, and a use of a demetallization auxiliary agent. The demetallization agent comprises a core-shell structure, is composed of an organic material with a chelating functional group, and comprises a core and a shell layer. The core is a sub-micron organic polymer particle, and the shell layer is an amphiphilic polymer with a functional group of strong electrostatic adsorption and metal chelating capacity connected to the surface. The preparation method of the demetallization agent comprises the steps of initiating connection and preparing the demetallization agent. The demetallization auxiliary agent has strong chelating capacity in an aqueous phase, and can transfer the metal chelated by the demetallization agent to the demetallization auxiliary agent. In addition, the application of the demetallization agent and the demetallization auxiliary agent to non-acid crude oil demetallization is disclosed. The demetallization agent and the demetallization auxiliary agent are suitable for removing metals such as nickel and vanadium in crude oil, have high demetallization agent grafting rate, increase the contact time of the demetallization agent and the oil phase, and have the characteristics of low cost, easy production and environmental friendliness.

The invention belongs to the technical field of catalytic materials, and particularly discloses an ionic liquid catalyst for preparing methylacrolein and a preparation method of the ionic liquid catalyst. According to the preparation method, ionic liquid (protonated morpholine hydrochloride or 1-butyl-3-methylimidazole chloride salt) and metal chloride are subjected to a reaction, metal chelating ionic liquid is obtained, and the ionic liquid catalyst is obtained. The ionic liquid catalyst disclosed by the invention is simple in synthesis operation and mild in reaction condition, and has good industrial amplification potential; compared with the traditional supported or single metal salt catalyst, the catalyst provided by the invention has the advantages that the metal ion loss or agglomeration phenomenon is not easy to occur in the use process, the service life of the catalyst is effectively prolonged, and the problem that the existing catalyst is easy to inactivate is solved; the catalyst is adjustable in active center, high in selectivity and excellent in catalytic performance.

The invention relates to the technical field of biomedical materials. The invention discloses a Schiff base-sulfonated hyaluronic acid light-cured microsphere as well as a preparation method and application thereof. The microspheres are prepared by condensing DL-lysine and paeonol to generate Schiff base, then conjugating the Schiff base with sulfonated hyaluronic acid through a carbodiimide chemical method, and finally molding by adopting a microfluidic technology and carrying out ultraviolet curing. The metal chelation characteristic of Schiff base is combined with the precise structure regulation advantage of the microspheres, and the prepared microspheres show an excellent synergistic effect when applied to the surfaces of implant materials such as degradable magnesium alloy, iron alloy and zinc alloy: the corrosion resistance of a base material can be remarkably improved, an effective protective layer is formed, and the service life of the microspheres is prolonged. Meanwhile, the compound has multiple biological functions of promoting endothelial cell proliferation, inhibiting excessive proliferation of smooth muscle cells and regulating and controlling macrophages to be polarized to anti-inflammatory phenotypes, and has a wide application prospect in the biomedical fields of intravascular stents, bone fixing instruments and the like.

The invention belongs to the field of waste battery material recovery, and provides a waste battery material recovery method based on a plasma chemical vapor deposition technology. Firstly, a network compound with a metal chelating function is synthesized and forms stable combination with active sites on the surface of an electrode in subsequent coating deposition, and harmful metal ions are effectively captured; secondly, a fluorine-containing imidazolyl-quaternary ammonium salt network compound is designed, and the fluorine-containing imidazolyl-quaternary ammonium salt network compound is endowed with excellent surface passivation and chemical stability by a fluorinated group; in the stripping process, the active material and the metal current collector are separated by periodically adjusting the temperature and combining the plasma technology, the stripped active powder can be further extracted and purified through acid pickling treatment, and the metal current collector is combined with a fluorine-containing compound and an inorganic silica network deposition process. The metal surface is endowed with good corrosion resistance and reprocessing performance, the method is suitable for recycling of electrode materials in waste batteries, and meanwhile the recycling value of related materials is improved.

The present application relates to the field of environment-friendly metal surface pretreatment technology, and discloses a metal chelating film forming agent, a preparation method and application thereof, wherein low-molecular polysilazane resin and zirconium triethanolamine compound are used as film forming agents, epoxy modified silicone resin is used as an auxiliary film forming agent, aspartic acid diacetic acid tetrasodium is used as a chelating dispersant, tetramethyl decyne glycol is used as a wetting agent, n-butanol is used as a leveling agent, and interface stable graphene with Schiff base functional groups, quinoline functional groups and quaternary ammonium salt functional groups on the surface is used as a corrosion-resistant filler to prepare the metal chelating film forming agent, wherein the present application is environmentally friendly, and after the leak detection process of the compressor muffler, no alkaline cleaning agent is needed for cleaning and treatment, and the subsequent spraying can be directly performed, on the other hand, the metal substrate surface can be combined by physical adsorption and chemical adsorption to produce strong bonding force, and a dense protective film is formed on the metal substrate surface, thereby achieving the beneficial technical effect of significantly improving the corrosion resistance.

Metal chelation compounds and associated coordination complexes are provided. In one aspect, this disclosure provides for a metal chelation compound, the compound having the general structure: D-L-T, wherein D is deferasirox or a derivative thereof, T is triapine or a derivative thereof, and L is a linking group and is a bond, C1-C10 alkyl, C2-C10 alkenyl, or —(C0-C3 alkyl)-R—(C0-C3 alkyl)-, wherein R is aryl, cycloalkyl, or polyethylene glycol.

The invention relates to the technical field of analytical chemistry detection, and discloses a method and a system for detecting thioctic acid in urine of people based on chromatography-mass spectrometry. The method comprises the following steps: adding a redox buffer system and a metal chelating system into a urine sample, and stabilizing the redox state of lipoic acid under a low-temperature condition; adding a stable isotope internal standard substance into the pretreated sample, and separating and enriching different oxidation-reduction-state compounds based on solvent polarity difference by adopting a liquid-liquid extraction technology; carrying out gradient elution separation by adopting ammonia water system liquid chromatography; simultaneously detecting oxidized lipoic acid and reduced lipoic acid in a tandem mass spectrum multi-reaction monitoring mode; and calculating an oxidation-reduction state concentration ratio by adopting a matrix effect correction algorithm to obtain a metabolic state evaluation index. The technical problem that the detection result is unstable due to the fact that the lipoic acid is in oxidation-reduction state dynamic balance in urine is solved, and the accuracy and comparability of lipoic acid metabolism state evaluation are improved.

The utility model discloses a wastewater heavy metal chelation precipitation reaction device concretely relates to wastewater treatment technical field, including the sedimentation tank and the silt discharge pipeline, the bottom of the right side of sedimentation tank installs the silt discharge pipeline, and the top inside of sedimentation tank is provided with pretreatment assembly. The utility model discloses be provided with pretreatment pipeline, and the wastewater enters the inside of pretreatment pipeline through sewage inlet pipe, and when staying in the inside of pretreatment pipeline, can add medicine through medicine inlet pipe and handle, after mixing, can start electric push rod, and the auxiliary ring cover slides along the pretreatment pipeline, and after the bottom groove of bottom side opens, can flow into the inside of sedimentation tank through the bottom groove and carry out the precipitation treatment, and the filter screen in the bottom groove can carry out the prefiltration treatment to sewage in this process, and handle the larger sundries in the sewage, realize the pretreatment function of the wastewater heavy metal chelation precipitation reaction device when using.

The invention discloses a cutting method for an LED epitaxial wafer, and relates to the technical field of wafer cutting, and the cutting method comprises the following steps: taking long-chain copolymer amphoteric buffer resin as a component A and an amino-functionalized metal chelating trapping agent as a component B, and mixing to prepare a protection solution; coating the protection liquid on the surface of the LED epitaxial wafer to form a liquid film; baking the liquid film to enable the solvent and volatile components in the liquid film to escape, and forming a solid protection layer on the surface of the LED epitaxial wafer; cutting the LED epitaxial wafer; and the cut LED epitaxial wafer is washed, so that the solid protective layer is dissociated rapidly, and cutting chips and metal slag are carried to thoroughly fall off from the surface of the wafer. According to the method, a protection system with stress buffering and active capturing functions is constructed, mechanical shearing force generated by high-speed cutting is effectively dissipated by utilizing molecular rheological characteristics, wafer edge breakage is prevented, thorough water washing desorption is realized through a hydrophilic induced swelling disintegration mechanism, and electrode oxidation and residue are avoided.

The invention belongs to the technical field of electromagnetic compatibility, and discloses a method for preparing a light magnetic carbon composite electromagnetic compatibility material by inducing chelate salt through carbon nitride, which comprises the following steps: 1, fully dispersing metal chelate salt and graphitized carbon nitride to form a uniform mixture; and 2, carrying out temperature programming calcination treatment on the uniform mixture to obtain the target magnetic carbon composite material. According to the present invention, the construction of the rich porous structure is achieved, the preparation process is simple and environmentally friendly, the template method adopted for the conventional porous structure inevitably comprises the introduction and the removal of the template agent in the whole production process, the use of the acid, the alkali or the oxidizing agent is involved, and the harm and the pollution are serious; the adopted carbon nitride template can be decomposed in the high-temperature pore-forming process for preparing the wave-absorbing agent, so that the problem of subsequent template removal is avoided.

An acid-resistant heavy metal adsorbent, the adsorbent has both sulfydryl and carboxyl, the adsorbent can form a multi-coordination stable structure after chelating with metal, and the molecular structural formula is.

The application discloses an injectable wound dressing with antibacterial and near-infrared response and a preparation method thereof, and belongs to the biomedical field.The wound dressing is made of components including the following raw materials: dendritic macromolecules, a biomacromolecule solution, a trivalent iron ion solution and a crosslinking agent solution.The wound dressing can be quickly prepared by mixing the biomacromolecule solution, the trivalent iron ion solution, the dendritic macromolecules and EDC / NHS to generate metal chelation and amide reaction, and has antibacterial and near-infrared response;the wound dressing is in a liquid state before gelation, has injectability and good adhesion, and can completely adhere to damaged skin to realize the function of protecting the skin;the wound dressing also has the advantages of high biocompatibility, simple preparation method, easy availability of raw materials and easy scale production.

The invention relates to the field of food science and engineering, and discloses a sodium-reduced preserved goose pickling liquid based on basic amino acid, a preparation method and application, the sodium-reduced preserved goose pickling liquid comprises deionized water, sodium chloride, potassium chloride and basic amino acid, and the basic amino acid is preferably a combination of L-lysine, L-arginine and L-histidine; the preparation and the application relate to a step-by-step dissolving and compounding process, a static low-temperature pickling process, a ventilation air drying process and a low-temperature curing process. Alkaline amino acid is introduced into a sodium-reduced and potassium salt substitution system, swelling of myofibrillar protein is promoted through side chain cationic groups of the basic amino acid, and oxidation reaction is blocked in combination with metal chelation and electron donor characteristics of the basic amino acid; the effects of reducing the sodium content, improving the gel network structure, inhibiting lipid oxidative rancidity and masking the bitter taste of potassium chloride are achieved, the problems of texture looseness and flavor deterioration caused by ion strength reduction of the low-salt meat product are solved, and the sensory quality and storage stability of the product are improved.

The application relates to the technical field of food safety detection, and discloses a pathogenic bacteria multi-modal detection method based on a nano-composite material and a neural network, which comprises the following steps: preparing a nano-composite material based on the metal chelating property and interface regulation technology of cuttlefish ink source nanoparticles; constructing a dual-mode immunosensing detection platform based on the nano-composite material and a lateral flow immunoassay detection platform; preliminarily detecting pathogenic bacteria based on the dual-mode immunosensing detection platform to obtain dual-mode detection signals; extracting multi-modal signal characteristics of the dual-mode detection signals based on a fusion architecture of a multilayer perceptron and a radial basis function; and analyzing the multi-modal signal characteristics based on a neural network algorithm and outputting detection results and prediction results of the pathogenic bacteria. The application combines nano-composite engineering, multi-modal signal transduction and machine learning organically, breaks through the bottleneck of traditional detection technology, and realizes dual-mode detection of rapid and accurate detection and risk assessment of foodborne pathogenic bacteria.

The invention discloses a thiourea acylthiourea metal complex catalyst, a preparation method thereof and application of the thiourea acylthiourea metal complex catalyst in lactide ring-opening polymerization. The preparation method comprises the following steps: (1) condensing 3, 5-bis (trifluoromethyl) phenyl isothiocyanate and para aminobenzoic acid in dichloromethane to obtain a carboxyl-containing product A; (2) performing acylating chlorination on the product A to obtain an intermediate B; (3) reacting the intermediate B with ammonium thiocyanate to generate an isothiocyanate intermediate C; (4) reacting the intermediate C with chiral primary amine to obtain a ligand intermediate D with a chiral center; and (5) coordinating the ligand intermediate D with a zinc compound or a titanium compound in an organic solvent to obtain the target catalyst. Molecules of the catalyst contain a chiral thiourea unit and an acylthiourea metal chelating unit at the same time, so that a monomer and an initiator can be activated synergistically. When being used for ring opening polymerization of lactide, the polylactic acid with high stereoregularity and narrow molecular weight distribution can be efficiently prepared at room temperature; the carbon nanotubes are added into a reaction system, so that the polylactic acid composite material with conductivity can be obtained.

The invention relates to the technical field of bioengineering, in particular to a double screening structure for a protein purification device, the double screening structure comprises a first screening assembly and a second screening assembly which are sequentially connected in series, and a target protein sample is sequentially screened through the first screening assembly and the second screening assembly; the first screening assembly comprises a metal chelating affinity chromatography column and a gel filtration chromatography column which are connected in series and are used for sequentially removing impurities mixed in a target protein sample; the second screening assembly comprises an ion exchange chromatographic column elastically mounted on the fixing frame, an inlet of the ion exchange chromatographic column is communicated with an outlet of the gel filtration chromatographic column, and target protein in the target protein sample is captured. According to the method, the target protein sample is purified from the three dimensions of affinity, molecular size and charge difference, the purification efficiency is greatly improved through a multi-layer screening mode, various impurities can be more effectively removed, and the target protein with higher purity is obtained.

The application discloses a kind of fertilizer additive based on sulphate lignin modification and its preparation method and use.The fertilizer additive is to sulphate lignin hydrothermal alkali cutting and obtains a water-soluble lignin-based material.This material is as a kind of polyphenol form lignin-based natural polymer compound, with superior metal chelation effect, can be used as a new type of natural polymer trace element chelation material, improve the growth of plant under the condition of trace element deficiency and promote plant growth.Take iron as an example, the mechanism of HSAL promoting plant growth is that the unique high-phenolic aromatic polymer structure on water-soluble HSAL can efficiently chelate and enrich the non-physiological active iron ions in the plant root environment and promote the efficient absorption and utilization of plants, so as to regulate the growth environment of plants and the form of trace elements in plants.This process further promotes the absorption of trace elements in plants and the distribution efficiency in vivo, so as to realize the promotion of plant growth.

The invention relates to the technical field of urokinase, and discloses a urokinase purification method and a chromatographic column type adsorption device for extraction, the purification method comprises the following steps: S1, taking a urokinase raw material, carrying out microfiltration, adding a chitosan quaternary ammonium salt solution, carrying out directional flocculation, centrifuging, and collecting a supernatant; s2, adding the supernate in the step S1 into a weak anion exchange chromatographic column, eluting, collecting eluent with active components, and desalting the eluent; s3, adding the eluent desalted in the step S2 into a gel filtration chromatography column, eluting, and collecting the eluent; s4, the eluent in the step S3 is added to a Ni-IMAC metal chelating chromatographic column, and purified urokinase is obtained after elution. According to the method, multiple chromatographic columns are used for chromatography, and cost and operation complexity are reduced.

The invention belongs to the field of biological medicine, and particularly relates to a protein purification method based on an anti-His tag monoclonal antibody. The antibody can recognize histidine tags with high specificity, an affinity chromatography medium prepared with the antibody as a ligand can efficiently purify His tag protein, the problem that metal ions fall off in traditional metal chelating chromatography can be effectively solved, and non-specific adsorption of impure protein is remarkably reduced. The purification method based on the medium has strong targeting capture capability, can greatly improve the final purity and yield of the protein with the histidine tag, and provides a reliable solution for obtaining the high-purity protein.

PSMA targeted metal chelate nanodrugs, methods of making these nanodrugs and methods of using them for radiodiagnosis and radiotherapy are provided.

This invention discloses a method for deashing polyolefins based on the synergistic effect of a bifunctional chelating agent and periodic supercritical CO2, belonging to the field of polyolefin material preparation technology. First, a bifunctional chelating agent with both CO2 affinity and metal chelating ability is synthesized. Then, polypropylene material and the chelating agent are placed in a high-pressure reactor, CO2 is injected, and the temperature and pressure are increased to a supercritical state. Under the condition of maintaining the supercritical temperature, the pressure is periodically controlled, causing the pressure to pulsate between high and low pressure, sequentially experiencing a swelling / permeation stage and an expansion / elution stage. After the cycle is completed, the pressure is released, and high-purity polypropylene is obtained after post-treatment. This invention transforms static diffusion mass transfer into forced convection mass transfer through periodic pressure control, achieving deep removal of metal residues with a removal rate as high as 97.14%. The total ash content of the product can be reduced to 5.29 ppm, with no significant impact on the properties of the polypropylene itself. It also features short processing time and significant environmental advantages.

The invention discloses a preparation method of an underwater polyurethane adhesive based on dopamine grafting and waste PET chain extension. The preparation method specifically comprises the following steps: carrying out purification treatment on a GLP degradation solution through silica gel column chromatography; the preparation method comprises the following steps: carrying out a reaction on PPG and IPDI to prepare an NCO-terminated polyurethane prepolymer; and under a water bath condition, adding the GLP degradation liquid after chromatography into the polyurethane prepolymer, stirring, adding a dopamine hydrochloride solution, stirring, pouring into a preheated polytetrafluoroethylene mold, storing at room temperature, and curing to obtain the underwater polyurethane adhesive. According to the preparation method disclosed by the invention, the polyurethane material is endowed with underwater self-adaptive adhesion capacity through the reversible oxidation-metal chelation effect of a dopamine catechol group. Hydroxyl and amino in dopamine can easily form hydrogen bonds with water molecules, so that the interaction force between molecules is increased, and the adhesiveness is improved. Meanwhile, water molecules can promote oxidation reaction of dopamine, so that chemical adsorption is generated between formation of polydopamine and the surface of an adhered object.

The invention discloses green antibiotic-free feed for quails in the egg producing period and a preparation method of the green antibiotic-free feed, and belongs to the technical field of animal feed. The feed additive comprises a composite additive composed of modified quercetin and modified gallic acid. The modified quercetin is subjected to acetylation, glycosylation, phosphorylation and deacetylation, so that the water solubility and bioavailability are improved; the modified gallic acid constructs a metal chelating compound through esterification, Michael addition and zinc coordination, the modified quercetin is responsible for core antioxidation, and the phytosterol component in the modified gallic acid synergistically regulates lipid metabolism, so that a multifunctional system capable of regulating antioxidation, calcium homeostasis and lipid metabolism in the egg laying period of quails is formed.

The application discloses a multifunctional laundry tablet and a preparation method thereof, and belongs to the technical field of daily washing materials. The multifunctional laundry tablet is prepared through ten continuous processes of dosing, mixing and stirring, discharging, semi-finished product detection, substrate preparation, sizing and casting film forming, drying, slitting, inner packaging, outer packaging, finished product inspection and warehousing, and is prepared from a core decontamination system of a compound anionic and nonionic surfactant, a heavy metal chelating component of disodium EDTA, a biological decontamination system of a protease and a composite enzyme, and a self-synthesized ultraviolet light crosslinking type anti-color-bleeding defoaming agent, and takes non-woven fabric as a carrier.

The application discloses a kind of multistage rigid-flexible heterostructure crosslinking magnetic polymer microspheres and its preparation method and application.The microsphere is the continuum of global chemical crosslinking, and its microstructure is composed of five parts of high-density rigid skeleton unit, flexible accommodation matrix unit, rigid-flexible transition interface unit, magnetic functional component and organic-inorganic hybrid interface layer.The application uses the strategy of step-by-step assembly-in-situ mineralization, uses RAFT active polymerization and starvation feeding process to construct nonlinear crosslinking density gradient network, and realizes the topological interlocking of magnetic component and polymer matrix by in-situ induction of metal chelating monomer to limit the growth of rare earth doped ferrite nanocrystal cluster.The application fundamentally eliminates the shell peeling risk caused by physical interface, realizes the zero leakage of magnetic component.The microsphere has the advantages of fast magnetic response speed, high structural stability and rich surface biological activity sites, and has important application prospect in the field of liquid phase biochip and in-vitro diagnostic reagent.

The invention discloses a low-damage fracturing fluid for a coal rock gas well and a preparation method of the low-damage fracturing fluid, and relates to the technical field of petrochemical engineering. When the low-damage fracturing fluid for the coal rock gas well is prepared, firstly, allyl phosphorus dichloride and 4-(dimethylaminomethyl) phenol react to prepare a double-bond di-tert-amine intermediate; reacting the double-bond di-tert-amine intermediate with halogenated alkane to prepare a gemini quaternary ammonium hydrophobic monomer; the preparation method comprises the following steps: reacting N, N '-ethylenediamine disuccinic acid with allyl glycidyl ether to prepare a metal chelating monomer; acrylamide, acrylic acid, fumaric acid, a metal chelating monomer and a gemini quaternary ammonium hydrophobic monomer are copolymerized to prepare modified polyacrylamide; and mixing the modified polyacrylamide with water and an auxiliary agent to prepare the low-damage fracturing fluid for the coal rock gas well. The prepared low-damage fracturing fluid for the coal rock gas well has the advantages of being low in damage, capable of expanding pores and increasing permeability, anti-swelling, resistant to temperature and shear and resistant to salt.