Surface modification of collagen fibers by low-temperature plasma technology:

By using low-temperature plasma technology to modify the surface of protein materials, it is clear that under the action of different plasmas, new active groups can be introduced on the surface of protein materials or protein fibers, or new functional groups can be introduced by grafting. The introduction of these groups, on the one hand, changes the surface properties of the material, such as hydrophilicity, surface polarity, surface charge, surface energy, etc., on the other hand, it creates conditions for further modification of the material, and these activities can be more easily passed through. The group realizes chemical cross-linking (modification) between fibers, and even provides the possibility to realize chemical reactions that cannot or are difficult to achieve under conventional conditions.

High-energy active particles (including ions, electron radicals, etc.) in low-temperature plasma. The active particles formed by these non-polymeric gases in the radio frequency electric field collide on the surface of the material, resulting in energy transfer, resulting in the breaking of surface chemical bonds, and some of them are generated Macromolecular free radicals, part of which are bound to the molecular bonds on the surface of the material, change the chemical composition of the surface of the material, thereby modifying the surface properties of the material.
The surface modification of natural collagen materials by low-temperature plasma technology, the treatment of collagen membrane materials by the glow discharge of controlled O2 and Ar gas, and the contact angle photoelectron spectroscopy and infrared analysis show that the polar groups (hydroxyl groups) in the material The carboxyl group is significantly increased, the contact angle of the material is reduced, and the surface energy is increased, thereby improving the hydrophilicity of the material.
The surface of collagen fibers is modified by low-temperature plasma, which can introduce different polar groups to increase the hydrophilicity of the fiber surface or improve its chemical reactivity. Changing the charge or isoelectric point of collagen fibers, such as increasing the carboxyl group on the peptide chain, will decrease the isoelectric point; increasing the amino group on the peptide chain will increase the isoelectric point. Weaken the hydrogen bond between the fibers and help to disperse the fibers.
The free radical fragments generated by the low-temperature plasma in the polymerizable gas medium are deposited on the surface of the material to form an extremely thin plasma polymerized film, which results in the change of the surface properties. For example, fluorine plasma is deposited on the surface of biological materials to improve the water repellency of the material; the organic silicon plasma film is deposited to improve its wear resistance, optical properties and wetting properties.
As an effective method for surface modification of biological protein materials, low-temperature plasma technology can quickly and efficiently change the surface properties and surface active groups of leather collagen fibers without pollution. By increasing the active groups on the surface of collagen fibers and reducing the activation energy between them and other chemical substances (tanning agents), it creates a good chemical basis for further chemical modification (tanning) of collagen fibers and improves the absorption and binding of chromium. Or make the non-toxic chemical substances that are not easy to produce cross-linking effect with collagen fibers in traditional tanning chemistry, and achieve high-efficiency tanning cross-linking effect.
By increasing the active groups on the surface of collagen fibers and reducing the activation energy between it and other chemical substances (tanning agents), it creates a good chemical basis for further chemical modification (tanning) of collagen fibers and improves the absorption and binding of chromium. Or make non-toxic chemical substances that are not easy to produce cross-linking with collagen fibers in traditional tanning chemistry, low-temperature plasma technology can achieve high-efficiency tanning cross-linking.