Regeneration of silk fibroin membrane by atmospheric pressure DBD plasma treatment: mechanical enhancement brought by surface activation and crystallinity improvement

Research Overview and Key Data

A study published in Polymers for Advanced Technologies used argon oxygen mixed gas atmospheric pressure dielectric barrier discharge (DBD) plasma for post-treatment of regenerated silk fibroin (RSF) films, and systematically investigated the changes in physical, chemical, structural, and mechanical properties of the films before and after treatment. The modification effect was characterized by water contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FIR), atomic force microscopy (AFM), scanning electron microscopy combined with energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and uniaxial tensile testing. The results showed that plasma treatment significantly improved the wettability of the film surface, reducing the water contact angle from about 80 ° to 20 °. AFM quantitative analysis showed that the average surface roughness (Ra) decreased from 9.64 nm to 7.32 nm, indicating a measurable change in the nanoscale surface morphology under the selected treatment conditions. ATR-FIR analysis showed subtle changes in the surface chemical environment, but the characteristic molecular structure of silk fibroin was preserved. XRD analysis showed that the crystallinity increased from 37.3% to 46.3%, reflecting the improvement of molecular order in the existing crystal regions, without the formation of new crystal phases.

Synchronous improvement of mechanical properties

Structural changes accompanied by enhanced mechanical properties: Young’s modulus increased from 3.30 GPa to 4.20 GPa, tensile strength increased from 53.46 MPa to 70.59 MPa, and elongation at break remained basically unchanged.

. Research suggests that atmospheric pressure DBD plasma provides an effective, environmentally friendly, and solvent-free post-treatment strategy for regulating the physical, chemical, structural, and mechanical properties of RSF films without compromising structural integrity. The simultaneous improvement of surface hydrophilicity, molecular organization degree, and mechanical properties also suggests that this type of plasma treated film has potential in advanced biomedical fields such as tissue engineering, wound healing, and implantable biomaterials.

Significance of polymer additives and electronic and electrical materials

Although the application scenario of this study is directed towards biomedical fields, the material processing and modification logic it reveals has reference value for the engineering plastics and flame retardant systems that the electronic and electrical column focuses on.

. Atmospheric pressure DBD plasma belongs to the dry surface activation method, which does not introduce solvents and can adjust surface wettability and nano roughness without changing the structure of the substrate. This has similarities with the requirements of packaging and encapsulation, cable and wire surface treatment, and interface bonding in electronic and electrical materials. For engineering plastic components that require both flame retardancy and weather stability, surface activation may affect the uniformity of subsequent coating, bonding, or encapsulation interfaces, while the increase in crystallinity and modulus suggests the potential of plasma treatment in regulating the mechanical properties of semi crystalline polymers. From the perspective of formulation design, plasma treatment itself does not replace stabilizing agents such as antioxidants, but can complement the additive system as a surface engineering process: the stability of the body relies on antioxidants and weather resistant stabilizing systems, while surface properties are finely adjusted through plasma activation. The coexistence of subtle changes in surface chemical environment and preservation of molecular structure observed in the study also reminds material engineers to simultaneously evaluate the impact of surface polarity changes on electrical properties and long-term weather resistance when introducing plasma processes. The characterization combination provided by this work – contact angle, AFM, FTIR, XRD, and tensile testing – can serve as a method reference for evaluating surface modification of engineering plastics for electronic and electrical applications.

Limitations to be noted

This study focuses on the specific biobased material of regenerated silk fibroin film, and the processing conditions are optimized argon oxygen atmospheric pressure DBD plasma. The conclusion cannot be directly extrapolated to flame-retardant engineering plastics or cable material systems.

. The study did not involve electrical performance, flame retardant rating, or long-term weather aging data, and the relevant application value still needs to be verified separately in the electronic and electrical material system.

Information source:Atmospheric Pressure Plasma Treatment of Regenerated Silk Fibroin Films: Surface Activation, Structural Reorganization, and Mechanical Enhancement， Organized by Herun Chemical.