93results about How to "Moderate mechanical strength" patented technology

The invention discloses preparation methods for a macroporous alumina carrier and a hydrodemetallization catalyst. The preparation method for the macroporous alumina carrier includes the following steps: (1) dry pseudoboehmite gel powder is hydrothermally processed under high pressure; (2) the dry pseudoboehmite gel powder obtained in step 1 is kneaded into a plastic, and pore-expanding agent is added in step 1 or step 2; (3) the plastic obtained in step 2 is shaped, the shaped material is dried and baked, and thereby the macroporous alumina carrier is obtained. The impregnation method is adopted to prepare the hydrodemetallization catalyst. The hydrodemetallization catalyst prepared by the method has large pore volume and pore diameter, centrally distributed pores, moderate mechanical strength and high activity and activity stability.

The invention discloses a method for preparing a hydro-demetalization catalyst for heavy oil. The method comprises the following steps of: firstly, preparing an alumina carrier, then, loading active metal components by using an immersion method, and obtaining the final hydro-demetalization catalyst after drying and roasting, wherein the process for preparing the alumina carrier comprises the following steps of: (1) evenly mixing pseudoboehmite dry colloidal powder with an extrusion aid, and then, adding an aqueous solution in which a physical pore-expanding agent and a chemical pore-expandingagent are dissolved, wherein the physical pore-expanding agent is a carbohydrate, and the chemical pore-expanding agent is phosphoric acid, phosphate or borate; (2) evenly mixing the materials prepared in the step (1), and then, forming; and (3) drying and roasting the materials prepared in the step (2) so as to prepare the alumina carrier. The hydro-demetalization catalyst for the heavy oil, prepared by the method disclosed by the invention, has the advantages of larger pore volume, larger pore diameter, concentrated pore distribution, good mechanical strength, and higher activity and higheractivity stability in the process of the hydro-demetalization for the heavy oil.

A polyurethane caulking material for expansion joints of a ballastless track of a high speed railway is disclosed. The caulking material is prepared from two parts A and B. the part A is composed of the following raw materials, by weight, 100 parts of isocyanate and its prepolymer, 10-150 parts of a plasticizer, 5-150 parts of a solid filler, 1-20 parts of a diluents, 1-5 parts of an adhesion promoter, 0-10 parts of a thixotropic agent and 1-3 parts of a water-removal agent. The part B is composed of the following raw materials, by weight, 10-20 parts of modified polyhydric alcohol, 1-5 parts of a diluent, 2-30 parts of a plasticizer, 5-30 parts of a solid filler, 0-5 parts of a thixotropic agent, 0.5-2 parts of an antifoaming agent, 0.1-1 part of an anti-aging agent and 0-0.01 part of a catalyst. The mass ratio of the part A to the part B is 4:1-10:1. The polyurethane caulking material has advantages of good low-temperature curing performance, high displacement capability, low tensile modulus, good bond property and excellent endurance quality and fatigue resistance, and is suitable for expansion joints of a ballastless track of a high speed railway as well as expansion joints of roads and airfield runways.

The invention belongs to the technical field of a lithium battery diaphragm, and particularly relates to a sodium alginate-based lithium battery diaphragm and a preparation method thereof. The lithium battery diaphragm adopts a sodium alginate-based composite nonwoven film as a base material and is prepared by adopting an electrostatic spinning process. The thickness of the prepared sodium alginate-based lithium battery diaphragm is 10 to 300 micrometers, the diameter of a fiber is 20nm to 2000nm, the ventilation is 1s to 600s / 100cc, the porosity is 40 to 90 percent, the aperture range is 0.02 to 4 micrometers, the absorption rate of the electrolyte is 150 to 900 percent, the heat stability is excellent, and the size shrinkage percentage at the temperature of 150DEG C is less than 0.5 percent. The sodium alginate-based lithium battery diaphragm is excellent in performance, high in ion electric conductivity, appropriate in mechanical strength and excellent in electrochemical stability; moreover, the interface stability between the diaphragm and a positive and negative material is improved, the rate capacity of a lithium battery can be greatly improved, the cycling life is long, and the safety performance is improved. Meanwhile, the preparation process is simple and easy, the production cost is low, and mass production can be easy to realize.

The invention relates to a hyperbranched polyester lithium ion battery gel electrolyte and a preparation method thereof. The gel electrolyte is formed by mixed liquor prepared from 5-30 percent by mass of hyperbranched photopolymer resin, 5-25 percent by mass of cross-linking agent, 1-10 percent by mass of initiator, 20-50 percent by mass of plasticizer, 20-50 percent by mass of lithium salt and the like by using a radiation crosslinking method or a heating crosslinking method and the like. In the invention, the hyperbranched structure of a hyperbranched polyester can effectively prevent chain segments from being crystallized, whereas the molecular conformation similar to a spheric shape can increase the free volume of the polyester; bigger space and fewer -COO- and ether bond structures among branch points of the hyperbranched polyester have very strong interreaction with oxygen in the carbonic ester plasticizer, and therefore, a large amount of liquid electrolyte can be contained, and the gel electrolyte has very high dissolving capacity on salts, which is beneficial to ionic migration and the increase of electrical conductivity so that a lithium ion battery prepared from the hyperbranched polyester lithium ion battery gel electrolyte has long service life, small internal resistance, better specific energy, simple preparation process and no pollution.

The invention discloses a room-temperature self repairing type thermoplastic polymer material based on a multi-layer microcapsule and a preparation method thereof. The thermoplastic polymer material comprises the following components in parts by weight: 70-95 parts of thermoplastic polymer base and 5-30 parts of filled multi-layer microcapsule for self repairing. The multi-layer microcapsule in the self repairing polymer material is a multifunctional intelligent multi-layer microcapsule combining a repairing agent and a catalyst. When a crack is generated in the base, the crack causes the capsule wall of the multi-layer microcapsule to crack together with the base, the liquid repairing agent at the capsule core part is released to be in contact with the catalyst on the middle capsule wall so as to initiate polymerization reaction at room temperature, and a generated new polymer bonds the cracked surfaces, thus preventing the propagation of the crack and repairing the crack. The multi-layer microcapsule used by the invention has moderate mechanical strength and favorable heat stability, and can endure the common thermal forming and processing technology of the thermoplastic material.

Production of amphiphilic chitose derivative and its usage are disclosed. The process is carried out by taking chitose as raw material, alkalizing, reacting with 4-methyl bromoethyl acid in 2-propanol medium to obtain 6-0-carboxy-propyl-chitose, purifying, and reacting with long-chain fatty acyl chloride to obtain N-acyl-6-0-carboxy-propyl-chitose. In chemical formula, R=-(CH) n, n=8, 10, 12, 14, 16 and 18. It has excellent biological compatibility and degradation, good tissue adhesion and mechanical strength. It can improve wound heal and have styptic and adhesion-preventing functions.

The invention relates to special-shaped hydrogel functional dressing and a preparation method thereof. The special-shaped hydrogel functional dressing comprises a hydrogel functional dressing body, wherein the hydrogel functional dressing body is sphere or hemisphere-shaped; the surface of the hydrogel functional dressing body is smooth or a bulge is formed on the surface of the hydrogel functional dressing body. The preparation method comprises the following steps: injecting hydrophilic high-molecular polymer aqueous solution with the mass content percentage being 5 to 7 percent into a mold, and preparing the special-shaped hydrogel functional dressing through a physical crosslinking method or a chemical crosslinking method. The special-shaped hydrogel functional dressing has good biocompatibility, and is non-irritative and non-sensitized to skin; the dressing has good transparency, and the condition of wound healing can be directly observed through the dressing; the dressing can provide wet environment for promoting wound healing, and does not adhere the wound, reduces scar hyperplasia and accelerates wound healing.

The invention discloses a high-activity hydrodemetallization catalyst and a preparation method of the high-activity hydrodemetallization catalyst. The catalyst uses alumina to serve as a carrier and uses MoO3 and NiO to serve as active components. The catalyst comprises active components by weight: 1.0-15.0% of the MoO3 and 0.5-6.0% of NiO, a pore volume of the catalyst is 0.80-1.40ml / g, a specific surface area is 180.0-250.0m<2> / g, a pore diameter is 10-20 nanometers and is 80%-90% of a total pore volume, and a crushing strength is 120-150N / cm. The preparation method of the high-activity hydrodemetallization catalyst comprises the steps of conducting molding, drying and roasting processes of an alumina supporter; adopting an immersing method to load metal components of Mo and Ni, conducting drying and roasting processes, roasting a molded supporter under a nitrogen atmosphere in the roasting process of the alumina supporter, and then roasting under an air atmosphere. The high-activity hydrodemetallization catalyst prepared by using the preparation method has high-activity stability, has a big pore volume and a pore diameter, has concentrated pore distribution and has moderate mechanical strength.

A purpose of the present invention is to further suppress the occurrence of spectral irregularities in a liquid crystal display device that uses a light emitting diode as a light source, and uses an oriented polyester film having a given retardation as a polarizer protective film. The liquid crystal display device includes a backlight light source, two polarizing plates, and a liquid crystal cell disposed between the two polarizing plates. The backlight light source is a white light source having a continuous emission spectrum. The two polarizing plates are each formed from a polarizer and protective films on both sides of the polarizer. At least one of the protective films on either side is an oriented polyester film having a retardation of 3,000 to 30,000 nm. The polarizing axis of the polarizer and the main orientation axis of the oriented polyester film, which is a protective film of the polarizer, are substantially parallel.

The purpose of the present invention is to further suppress the occurrence of spectral irregularities in a liquid crystal display device that uses a light emitting diode as a light source, and uses an oriented polyester film having a given retardation as a polarizer protective film. This liquid crystal display device includes a backlight light source, two polarizing plates, and a liquid crystal cell disposed between the two polarizing plates. The backlight light source is a white light source having a continuous emission spectrum. The two polarizing plates are each formed from a polarizer and protective films on both sides of the polarizer. At least one of the protective films on either side is an oriented polyester film having a retardation of 3000 to 30000 nm. The main orientation axes of the oriented polyester films configuring the two polarizing plates are substantially parallel to each other.

The invention belongs to the technical field of medicine, and relates to a metabolic enzyme-hydrogel system for drug metabolism, drug effect, and toxicity evaluation. The system is composed of drug metabolic enzymes and hydrogel carriers, wherein the drug metabolic enzymes are composed of protein macromolecules having metabolism functions such as microsomes, recombinant enzymes, and the like; and the hydrogel carriers are prepared by carrying out reactions among pluronics, amine acrylate, and diamine acrylate in the presence of a catalyst namely N,N,N',N'-tetramethyldiethylamine. The metabolic enzyme-hydrogel system is prepared by the following steps: subjecting the interlinked hydrogel carriers to pretreatments of cleaning and freeze-drying, and absorbing drug metabolism enzymes with controllable concentration by the hydrogel carriers so as to form the metabolism-hydrogel system. The metabolism enzyme-hydrogel system has the advantages of proper mechanical strength, non-toxicity, good repeatability, convenient operation, and thermal sensitivity, is capable of comprehensively predicting the effects of drugs and metabolic substances thereof on cells, and thus precisely evaluates the drug effect and toxicity of the drugs.

The present invention relates to a laminated glass, particularly to a heat strengthening laminated glass with a suitable middle region mechanical strength and a high edge region mechanical strength, wherein the heat strengthening laminated glass comprises a first glass plate, a second glass plate and an intermediate film, at least one of the first glass plate and the second glass plate is a heat strengthening glass plate, the heat strengthening laminated glass comprises a middle region and an edge region, and the edge region comprises an edge compressive stress region and an edge tensile stress region, wherein the maximum edge compressive stress of the edge compressive stress region is more than 18 MPa, the maximum edge tensile stress of the edge tensile stress region is less than or equal to 7 MPa, and surface stress of the heat strengthening laminated glass is more than 6 MPa and is less than 14.8 MPa. The heat strengthening laminated glass has the following advantages that: penetration resistance is good, safety performances and regulatory requirements of vehicle parts are met, and damage on the glass periphery during an installation and use process can be avoided.

The invention relates to a large-size lithium vanadate nonlinear optical crystal and a preparation method and application thereof. A high-temperature solution method is adopted for the crystal, a fluxing agent PbF2 is adopted for growing the crystal, and the nonlinear optical effect is about 8 times that of KDP (KH2PO4). The crystal has the advantages of being moderate in mechanical strength, easy to machine, not prone to air-slaking, fast and easy to prepare, low in cost, large in size and the like, is suitable for manufacturing nonlinear optical devices and can be widely applied to infrequency-doubling conversion nonlinear optical devices and the like.

The invention discloses enclosed mud for underground excavation tunnel ultra-deep hole grouting. The enclosed mud is used for bearing high pressure during underground excavation tunnel ultra-deep hole grouting so that it can be guaranteed that grouting slurry does not overflow during high-pressure grouting. The enclosed mud is mainly formed by mixing cement, bentonite, water and admixtures, wherein the volume ratio of the cement to the bentonite to the water to the admixtures is 1: m: n: 0.03, m ranges from 1.2 to 1.5, n ranges from 1.5 to 2, accordingly enclosed mud slurry can bear high pressure during high-pressure grouting, solidification time of the enclosed mud slurry is controlled within 2-5 days, and the strength increasing rate of the enclosed mud slurry is controlled to meet grouting conditions. The enclosed mud for underground excavation tunnel ultra-deep hole grouting bears high pressure during high-pressure grouting and can solve the problem that slurry enters a sleeve valve tube in the grouting process due to grout leaking and solve the problem that the sleeve valve tube is blocked due to deformation.

The invention relates to a mineralized collagen based skull repairing device and a manufacturing method thereof. The mineralized collagen based skull repairing device is made of a mineralized collagen / PCL (polycaprolactone) composite material; and the appearance of the repairing device comprises a spherical segment cap at the upper part and a cylindrical plug at the lower part. A separation mold and a secondary pouring technology are adopted during preparation of the mineralized collagen based skull repairing device, and the product defect caused by air residue at the blind end of the mold is overcome. The skull repairing device made of the mineralized collagen / PCL composite material has excellent osteogenic activity, the material is gradually and passively degraded under the creeping substitution action of cells, and growth of new bones can be guided at the skull defect part. A degradation product of the composite material is neutral, acidic materials causing aseptic inflammation cannot be generated, and new bone formation isn't affected; and through composition of PCL, the skull repairing device has excellent elasticity and toughness besides enough crush resistance and bending strength, and the repairing requirement of a skull of a human body is met.

The invention discloses a method for preparing an alumina supporter with large pore volume. The method comprises the following steps: (1) weighing a certain amount of pseudoboehmite dry glue power and a certain amount of extrusion assistant agent to be evenly mixed and then adding an aqueous solution containing a peptizing agent and a chemical pore-enlarging agent; (2) evenly mixing materials obtained in the step (1) and extruding a mixture into strips; and (3) drying and calcinating the material obtained the step (2) to prepare the alumina supporter; wherein the peptizing agent in the step (1) is gluconic acid or mixed organic acid containing the gluconic acid. The using amount of the gluconic acid or the mixed organic acid containing the gluconic acid is 3%-10% by weight of pseudoboehmite dry glue power. The catalyst prepared by means of the preparation method is large in pore volume and pore diameter, concentrated in pore distribution and moderate in mechanical strength and is suitable for the fields of preparation of heavy oil hydrogenation demetalization catalysts, residual oil hydrogenation demetalization catalysts and the like.

The invention relates to a method for preparing activated carbon fiber medical dressing. The method specifically comprises the following steps: (1) carrying out pretreatments on a clean raw material fiber, such as deoiling, roughening and activating, and cleaning the clean raw material fiber; (2) chemically silvering the fiber, and supplementing related consumed functional components in the plating solution after the plating operation; (3) washing, dewatering and drying the silver-loaded fiber; (4) pre-treating, carbonizing and activating the silver-loaded fiber. The method is simple in process and principle, the used chemical silvering solution is stable and is suitable for mass production, and granules in the prepared silver-loaded carbon fiber material are firm in binding force with the matrix, moderate in mechanical strength, excellent in antibacterial ability and continuous in stability, so that the silver-loaded carbon fiber material has a broad application prospect in the healthcare industry.

This invention discloses a method for preparing polyacrylamide macroporous gel carrier for immobilized cells. The method comprises: preparing a mixed solution of acrylamide monomer and N,N'-methylene bis-acrylamide monomer, adding NaCl into the mixed solution to saturation, transferring the mixed solution into a container for preparing gel carrier, uniformly adding NaCl powder to 2-5 cm above the solution surface, exhausting oxygen in the mixed solution and in the container, sealing the container, radiating with radioactive rays so that acrylamide monomer and N,N'-methylene bis-acrylamide monomer polymerize to obtain a gel, and heating the gel in a water bath to obtain polyacrylamide macroporous gel carrier for immobilized cells. The polyacrylamide macroporous gel carrier can be used in immobilization of microbes, such as a mixture of bacteria and fungi, and mixed bacteria for cellulose degradation.

The invention discloses single cylinder type anaerobic-aerobic composite microencapsulation biological fluidized bed automatic control equipment, wherein an anaerobic fluidized bed body is a reaction area which is, from top to bottom, orderly provided with a water inlet(outlet), a water distribution machine, an electric heating pipe, a grille, an overflow opening, a lighting device, a sampling opening, an automatic detection device and a material feeding and gas exhaust device; water source enters from the bottom of the anaerobic fluidized bed through an ultraviolet sterilizer, and a microbe capsule is driven to keep in fluidized state by water flow; wastewater in the anaerobic fluidized bed directly flows in a pollution discharge pond or an aerobic fluidized bed through the water outlet pipe on the bottom; an aerobic fluidized bed body is similar to the anaerobic fluidized bed body, but the difference lies in that an aeration disk is used to replace the water distribution machine, and the microbe capsule is driven to keep in the fluidized state by air flow; and because channels of the anaerobic fluidized bed and the aerobic fluidized bed are provided inside with one-way valves, the anaerobic fluidized bed and the aerobic fluidized bed can independently work. Under the condition of saving labor, the equipment realizes that the high-concentration polluted wastewater is denitrified and dephosphorized with high efficiency, and the pollution discharge meets the national standards; moreover, the equipment also has the advantages of simple structure and automatic operation.

The invention discloses a preparation method of artificial liposome, belongs to the field of pharmacy, and relates to a preparation method of protein medicament liposome. In the preparation method, nano spherical grain yolk lecithin zirconium or soya bean lecithin zirconium is used as a carrier, and balsam pear protein MAP30, fleece-flower root protein GAP31, lipase CRL or bovine serum albumin (BSA) is used as a wrapping protein. The preparation method comprises the steps of: adding phosphate buffer solution to the carrier material, stirring under the conditions of the temperature being 4 DEG C and rotation rate being 3500rpm to obtain a colorless and transparent dispersion, dissolving the wrapping protein in a phosphate buffer solution, then slowly dropwise adding to the dispersion, quickly stirring in the low-temperature condition to form stable liposome, centrifugally separating out protein, repeatedly washing, centrifuging, and freeze-drying at low temperature to obtain a finished product. The method has the characteristics of simple process, mild condition, high repeatability, high protein adsorption capacity and stable liposome structure.

The invention discloses a blood purification membrane and a preparation method thereof. The blood purification membrane mainly comprises, by mass, 18-48 parts of collagen, 16-37 parts of silk protein, 8-23 parts of fibroin, 6-19 parts of sericin, 1-17 parts of polyether sulfone, 1-7 parts of sulfonated polyether sulfone, 5-24 parts of heparin, 2-14 parts of lysine, 2-13 parts of cellulose acetate and 25-58 parts of double distilled water. The blood purification membrane has the advantages that the prepared blood purification membrane is good in permeability for solute to be removed, and the rate of intercepting protein in blood is high; the prepared blood purification membrane has a good effect of preventing bacteria and viruses and is good in water permeability; the prepared blood purification membrane will not cause a coagulation response and pyrogen reaction; the prepared blood purification membrane has good compatibility with the blood and is appropriate in mechanical strength.

The invention relates to the field of microbial fermentation, in particular to a natural wood fiber carrier for microbial immobilization and a preparing method of the natural wood fiber carrier. The method includes the following steps that (1) natural wood fiber materials relatively even in texture are selected, and mechanical pretreatment is carried out on the natural wood fiber materials; (2) water is added into a high temperature and high pressure reaction still, and then the natural wood fiber materials treated in the step (1) are added; (3) the natural wood fiber materials obtained in the step (2) and water are jointly heated and pressurized to the appointed temperature and appointed pressure so as to make a hydrothermal reaction, and the hydrothermal reaction is continuously made for appointed time; (4) after the hydrothermal reaction in the step (3) is finished, the temperature and pressure in the high temperature and high pressure reaction still are decreased, and the natural wood fiber materials obtained after hydrothermal treatment are taken out; and (5) the natural wood fiber materials obtained in the step (4) are washed and dried to obtain the natural wood fiber carrier. By means of the natural wood fiber carrier and the preparing method, the microorganism fixing effect is improved, significance in microbial immobilization is achieved, and the application prospect is wide.

The invention relates to a cable ladder formed by two beams (1a) and a number of crossbars (2A), all formed by extruded profiles made of a polymeric material. The beams (1) have a channel (4a) that receives a corresponding end of the crossbars. The channel (4a) has a lower wing (5a) and an upper wing (6a). A recess (7a, 8a) of the lower wing (5a) or upper wing (6a) has a number of openings (9a) along the longitudinal direction of the beam (1). The ends of the crossbars (2A) pass through the opening (9a) of the recess (8a) and have a reduction (10A) into which a corresponding part of the channel (4a) clips. The lower wing (5a) of the beams (1a) is folded over itself via a folding line (19a), such that a final section of the lower wing (5a) undergoes a lowering by means of elastic bending when the end of the crossbar (2A) is introduced.

A surface wetting treatment method for battery cell diaphragm of new energy automobile battery includes preparing diaphragm, extracting diaphragm, preparing a coating agent, drying the diaphragm, coating the diaphragm, preparing a polyester fiber membrane, unifying two membranes, and performing immersion treatment and vacuum plating. The present invention is characterized in that a diaphragm is made of a mixed material of polypropylene and polyethylene, compared with polypropylene, the diaphragm resists high temperature; compared with polyethylene, the diaphragm resists low temperature; combined with the composite of polyester fiber membrane, the diaphragm has thermal stability, high temperature resistance, low temperature output, long charging cycle life, moderate mechanical strength; andthrough the effect of the extracting agent, the invention facilitates the extraction of the soluble substance after the film is formed, makes the diaphragm into a microporous structure, and cooperates with the stretching action before and after the extraction to make the micropores more uniform, so that the permeability is stronger even when the electrolyte ions are transmitted, and the tensile strength and the mechanical properties of the diaphragm are improved by stretching, so that the diaphragm is not easy to be broken.

An explosive material composition containing, as an active ingredient, particles of a water-soluble reactive ingredient having an uniform particle size. Each particle is coated with an oil ingredient and / or a thickener. The coated particles form an agglomerate.

The invention provides a method for preparing a micro-fluidic / milli-fluidic chip by using a detachable template. The method comprises steps as follows: a, a detachable container is prepared; b, a pipeline is reserved, and the template is prepared; c, a prepolymer is poured and a die is solidified; d, an aluminum foil, a glass sheet and the template of the die are detached, and a micro-fluidic / milli-fluidic chip blank is obtained; e, the micro-fluidic / milli-fluidic chip blank is cut, and the micro-fluidic / milli-fluidic chip is obtained. The method has the characteristics that the processing technology is simple, controllability is high, and the stability of the obtained chip is good.

The invention provides a four-strain flu vaccine soluble microneedle patch comprising a needle body and a backing. The needle body is composed of a matrix material, a heat-resistant protective agent,a four-strain flu vaccine and a solvent. The matrix material is a mixture of at least two of a methyl vinyl ether-maleic anhydride copolymer, chondroitin sulfate, polyvinyl alcohol and polyvinyl pyrrolidone; the heat-resistant protective agent is trehalose, the solvent is deionized water. The prepared four-strain flu vaccine soluble microneedle patch has moderate mechanical strength of the needlebody and can effectively penetrate skin, and the vaccine is dissolved quickly in the skin; moreover, the prepared microneedle has good long-term stability of the vaccine in the needle body.

The invention relates to hydrogel for being injected into an organism and application thereof. The hydrogel is formed by mixing and crosslinking alkaline earth metal salt, an aqueous solution containing auxiliary materials and an alginate aqueous solution in a constant-temperature environment, and the energy storage modulus of the hydrogel is 60%-85% of the final energy storage modulus of the hydrogel; and the alkaline earth metal salt is alkaline earth metal salt containing magnesium, calcium, strontium and barium, and the form of the alkaline earth metal salt is at least one of sulfate, citrate, gluconate, lactate, carbonate, phosphate and alginate. The hydrogel disclosed by the invention is good in injecting property, can smoothly pass through a relatively long catheter, is not easy to block a needle head, also has proper mechanical strength, can resist in-situ pressure in tissues, and ensures that the hydrogel stays at a position needing to be filled after injection.