Effect of plasma immersion ion implantation on polycaprolactone with various molecular weights and crystallinity

Abstract

Polycaprolactone with five different molecular weights was spin-coated on silicon wafers and plasma immersion ion implanted (PIII) with ion fluence in the range 5 × 10-2 × 10 ions/cm. The effects of PIII treatment on the optical properties, chemical structure, crystallinity, morphology, gel fraction formation and wettability were investigated. As in the case of a number of previously studied polymers, oxidation and hydrophobic recovery of the PIII treated PCL follow second order kinetics. CAPA 6250, which has the lowest molecular weight and the highest degree of crystallinity of the untreated PCL films studied, has the highest carbonization of the modified layer after PIII treatment. Untreated medical grade PCL films, mPCL PC12 (Perstorp) and mPCL Osteopore have similar chemical structures and crystallinity. Accordingly, the chemical and structural transformations caused by PIII treatment and post-treatment oxidation are almost identical for these two polymers. In general, PIII treatment destroys the nano-scale lamellar structure and results in a reduction of PCL crystallinity. Examination after washing PIII treated PCL films in toluene confirmed our hypothesis that cross-linking due to PIII treatment is significantly higher in semi-crystalline PCL as compared with amorphous polymers.

Atmospheric Pressure Plasma Jet Treatment of Polymers Enables Reagent-Free Covalent Attachment of Biomolecules for Bioprinting

“…SDS washing removed protein from untreated controls as observed above with LDPE and as in previous studies. 27 The persistence of the amide peaks after SDS washing shows that the protein is covalently attached to the APPJ-treated PCL.…”

“…The SDS wash was conducted in 5% (w/v) SDS solution at 40 °C to maintain the temperature below the melting point of the PCL samples. 27 The difference spectra were obtained by subtraction of spectra of control samples, scaled so as to remove the dominant PCL vibration lines. The difference spectra were normalized to the intensity of the 1724 cm −1 PCL vibration line of the corresponding protein-coated sample spectra.…”

“…The samples were incubated for 22 h. The same treatment parameters were used as for the BSA test on LDPE described above and in Section . The SDS wash was conducted in 5% (w/v) SDS solution at 40 °C to maintain the temperature below the melting point of the PCL samples . The difference spectra were obtained by subtraction of spectra of control samples, scaled so as to remove the dominant PCL vibration lines.…”

Effects of Polymer Blending on the Performance of a Subcutaneous Biodegradable Implant for HIV Pre-Exposure Prophylaxis (PrEP)

“…The XRD data were analyzed using the MDI Jade version 9.6 software and the 2019 ICDD PDF 4+ database was used to search match crystalline phases present in the materials. The crystallite size was determined via the Scherrer equation (3): where L = crystallite size, K = Scherrer constant (0.94 from literature) [ 45 , 46 ], λ = X-ray wavelength, β = full-width at half maximum of a crystallographic peak, and θ = Bragg angle.…”

Characterization of a Reservoir-Style Implant for Sustained Release of Tenofovir Alafenamide (TAF) for HIV Pre-Exposure Prophylaxis (PrEP)

“…The MDI Jade version 9.6 software (MDI, Livermore, CA, USA) was used to analyze results and the 2019 International Center for Diffraction Data (ICDD) PDF 4+ database was used to search match crystalline phases present in the materials. The crystallite size was determined via the Scherrer equation (Equation (3)): L=Kλβcosθ where L = crystallite size, K = Scherrer constant (0.94 from literature [51,52]), λ = X-ray wavelength, β = full-width at half maximum of a crystallographic peak, and θ = Bragg angle.…”