32results about How to "Raise the isoelectric point" patented technology

The invention discloses positively charged nano yttrium oxide and a preparation method thereof. The isoelectric point of nano Y2O3 with positive charges on the surface is 8-10, the Zeta potential of the surface is 20-30mV when the pH is 7, and the average size of the nano Y2O3 particles is 20-80nm. In the invention, an alcohol-water mixture is used as a reaction solvent, homogeneous nucleation of a yttrium-containing precursor is promoted by use of the solubility difference of the reactant in two solvents, and nano Y2O3 with relatively strong electropositivity and relatively high isoelectric point is obtained through high-temperature thermal decomposition. The method comprises the following specific steps: preparing an alcohol-water mixture according to a certain ratio as a solvent; separately adding a yttrium-containing compound and a precipitator; heating for reacting for homogeneous nucleation to obtain a yttrium-containing precursor; filtering the yttrium-containing precursor, washing and drying; and performing high-temperature thermal decomposition under the protection of a nitrogen atmosphere in a tube furnace to obtain surface positively-charged nano Y2O3. The invention is simple in technology, low in cost and suitable for industrial production.

The invention discloses an aminated modified sugar-based aldehyde tanning agent, which is prepared from the following raw materials in proportion by weight: 100 parts of sugar-based aldehyde tanning agent, 4-10 parts of amino compounds; the aminated modified sugar-based tanning agent provided by the invention In the preparation method of the sugar-based aldehyde tanning agent, after the first step of reaction, it can be directly filtered and separated to obtain high-concentration sugar-based aldehyde tanning agent and iodate precipitation, which simplifies the preparation process and significantly reduces the amount of amination modification. Preparation costs of sugar-based aldehyde tanning agents.

The invention relates to a guided tissue regeneration membrane and a preparation method thereof. The method comprises: a pretreatment step, i.e. collecting a mammalian peritoneum, conducting flowing water washing, hair removal and preliminary degreasing for standby use; an antigen removal treatment step, i.e. carrying out further degreasing on the standby peritoneum by means of an enzyme treatment process, an alkali treatment process, an acid treatment process and a hypertonic treatment process, and removing immunogenicity; a collagen fiber contraction treatment step, i.e. carrying out dehydration, non-hydrophilic substance removal and washing treatment on the peritoneum subjected to the antigen removal treatment so as to contract the collagen fibers of the peritoneum; and a drying step, spreading the contracted peritoneum on a culture dish surface to make the compact layer of the peritoneum contact the culture dish, rapidly transferring the peritoneum into a refrigerator at a temperature ranging from -60 to -80DEG C to undergo pre-freezing for 1-8h, then freeze-drying the peritoneums in a freeze dryer for 24-36h, thus obtaining a collagen membrane able to guide tissue regeneration. The guided membrane provided by the invention has a compact layer and a loose layer, also has good biocompatibility, hydrophilicity and bone induction ability, and has a long in-vivo degradation time.