2results about How to "Increase negative charge" patented technology

The application discloses a salt-resistant water-non-dispersible material for oil well cement and a preparation method thereof. The salt-resistant water-non-dispersible material for oil well cement comprises the following components in the form of weight parts: 100 parts of N,N-dimethyl acrylamide, 3-6 parts of acrylic acid, 10-20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 5-15 parts of a cyclic monomer, 0.1-0.4 parts of a branching agent, 5-15 parts of a cationic monomer, 0.3-3 parts of a crosslinking agent and 400-500 parts of water. The salt-resistant water-non-dispersible material prepared by the application has good salt resistance, can significantly improve the anti-dispersion performance of the cement slurry when used in a salt water and sea water cement slurry system with a NaCl content of 18 wt% or less, and has excellent rheological performance.

The invention relates to a method for preparing a nanofiltration membrane by using sodium p-styrenesulfonate as a water phase additive. Infiltrating the support membrane in a water phase solution containing sodium p-styrenesulfonate and piperazine so that the support membrane is fully infiltrated by the water phase solution; coating the surface of the membrane with the oil-phase solution, and carrying out interfacial polymerization reaction to form an aromatic polyamide separation layer; and placing the membrane in an oven at 70-90 DEG C for heat treatment to prepare the aromatic polyamide composite nanofiltration membrane. Sodium p-styrenesulfonate can reduce the interfacial tension of a water / oil phase in the interfacial polymerization process, promote diffusion and uniform distribution of piperazine, strengthen the interfacial polymerization reaction and improve the cross-linking degree of a separation layer. The aromatic polyamide composite nanofiltration membrane prepared by the method has the characteristics of high flux and high selectivity at the same time. The method has the advantages of being simple in preparation process, low in cost and easy to implement. In addition, reference can be provided for preparation of other high-performance interfacial polymerization nanofiltration membranes.