3 results about "Gas foaming" patented technology

The present application belongs to the technical field of polymer porous foaming material and semiconductor precision cleaning consumables, and particularly relates to a PVA porous foaming material, a preparation method and a semiconductor wafer cleaning brush. The preparation method provided by the present application does not need to use solid particle pore-forming medium, polyvinyl alcohol is dissolved in water to form a glue solution, a surfactant and an acidic catalyst are added to adjust pH and filter, inert gas is introduced for foaming, a formaldehyde solution is added, and the product is obtained through gradient temperature solidification, demolding cleaning and drying. The PVA porous foaming material prepared by the present application has a regular and uniform multi-stage pore structure, the main foam holes are nearly spherical and interconnected to form a three-dimensional network structure. The prepared semiconductor wafer cleaning brush has excellent hydrophilicity, flexibility, high elasticity and high rebound characteristics, no particle precipitation and debris shedding occur in the use process, can meet the ultra-high cleanliness requirement of high-end semiconductor processes, simultaneously simplifies the production process, reduces the environmental protection cost, and has a good industrial application prospect.

This invention relates to a method for preparing a mineralized fiber scaffold composite injectable macroporous hydrogel that mimics natural bone emulsion (ECM). The method proposes preparing a PBLG fiber scaffold using electrospinning, gas foaming, and in-situ mineralization. Subsequently, the mineralized fiber scaffold composite injectable macroporous hydrogel is constructed through negative pressure perfusion, mechanical fragmentation, and gel fragmentation and reorganization. The mineralized fiber scaffold composite injectable macroporous hydrogel prepared by this invention can adapt to irregular bone defect areas, providing temporary support after implantation and offering excellent osteogenic induction and angiogenic activity for subsequent bone defect repair. The macroporous structure formed by microgel reorganization also supports the ingrowth of new tissue. This material has promising applications in bone defect repair and can also be extended to other medical fields such as cartilage defect repair and drug delivery.

The application provides a preparation method of low-density PLA foamed material and belongs to the field of polymer foaming. The application inhibits the hydrolysis of PLA by adding a suitable hydrolysis inhibitor, and the hydrolysis inhibitor can be branched with PLA to make the PLA have a long-chain branched structure, thereby supporting the growth of the cells; the nucleating agent improves the cell nucleation density; the problem of insufficient melt strength caused by the hydrolysis of PLA is solved by adjusting the first saturated adsorption time, and the first saturated adsorption time in the scope of the application can make the gas foaming agent fully dissolved in the polymer, so that the gas foaming agent is sufficient to support the nucleation and growth of the cells in the foaming process; the temperature of the first saturated adsorption is controlled to make the melt strength of the PLA support the growth of the cells; the pressure of the first saturated adsorption is adjusted to make the adsorbed gas sufficient to support the nucleation and growth of the cells in the pressure relief foaming process; and the three-time pressure relief foaming further improves the foaming ratio of the PLA foamed material.