Wide angle X-ray diffraction patterns and 2D-correlation spectroscopy of crystallization in proton irradiated poly(ether ether ketone)

Microscopic and Biomechanical Analysis of PEEK Interspinous Spacers for Spinal Fusion Applications

Spinal fusion is a surgical intervention used to join two or more vertebrae in the spine. An often-used method involves the placement of intervertebral spacers. They are commonly composed of biocompatible materials like polyetheretherketone. It has strength, longevity, and the capacity to interact harmoniously with the human body. Standardized mechanical tests were performed on two distinct implants to assess their biomechanical characteristics. The studies were conducted at a velocity of 2 mm/min. The stopping criteria were determined based on the loads sustained by the 50th percentile. Furthermore, the chemical composition of the implants was assessed using Raman spectroscopy. The implant created via subtractive manufacturing has a significant change in its elastic region at a force of 1300 N, and it begins subsidence when vertebrae are subjected to a load of 1500 N. The integration of microscopic characterization techniques with the mechanical analysis of prostheses in numerous case studies facilitates the biomechanical evaluation of implants.

Removal of Cr(VI) from aqueous solutions by activated carbon and its composite with P2W17O61: A spectroscopic study to reveal adsorption mechanism

Molecular scale information is needed to understand ions coordination to mineral surfaces and consequently to accelerate the design of improved adsorbents. The present work reports on the use of two-dimensional correlation Fourier Transform infra-red spectroscopy (2D-COS-FTIR) and hetero 2D-COS-FTIR- X-ray diffraction (XRD) to probe the mechanism of Cr(VI) removal from aqueous solutions by activated carbon (AC) and its composite with P2W17O61 (AC-composite). The adsorption data at an initial Cr(VI) concentration of 320 mg L-1 (320 ppm) revealed maximum adsorption capacities of 65 mg g-1 for AC and 73 mg g-1 for AC-composite, corresponding to removal percentages of 83 % and 94 %, respectively. The adsorption mechanism of Cr(VI) onto AC involved electrostatic attraction of charged ions, reduction of Cr(VI), orientation of O-H groups, complex formation and ion exchange reaction. On the other hand, ion exchange reactions were not observed in the case of AC-composite, but increasing reduction and complex formation due to the presence of W were more pronounced. Moreover, a monosubstituted compound; i.e. K6P2CrW17 O61·nH2O, having chromium in its maximum oxidation state (Cr(VI)) was formed. These resulted in an improved adsorption capacity of AC-composite towards Cr(VI) in comparison to AC, and could explain the differences in adsorption thermodynamics and capacity of the two studied adsorbents. High value information could be extracted from both FTIR spectroscopy and XRD patterns when combined with available 2D-COS routines and subsequently powerful tools to investigate the mechanisms of adsorption are obtained.

Spectroscopic investigations to reveal synergy between polystyrene waste and paraffin wax in super-hydrophobic sand

Sand based superhydrophobic materials, such as paraffin-coated sand, are the focus of global research to fight land desertification. The present work investigates the development of paraffin-coated sand with extending service life as well as improving and stabilizing hydrophobic property by adding plastic waste. While the addition of polyethylene (PE) did not improve the hydrophobic property of paraffin coated sand, incorporating 4.5% of polystyrene (PS) in the composition of coated sand increased the contact angle. Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction patterns (XRD) and two-dimensional correlation spectroscopy (2D-COS) indicated that PS increased the molecular orientation of sand and reduced the thickness of the paraffin coating. Paraffin on the other hand improved the distribution of PS and prevented aggregation with sand. Both FTIR bands at 1085 cm^-1 and 462 cm^-1 were more sensitive to change in PS contents, while other bands at 780 cm^-1 and 798 cm^-1 were more sensitive to change in paraffin contents. Moreover, the XRD patterns of sand were split into two components by the addition of PS indicating the transformation of morphology to less ordered or more distorted form. 2D-COS is a powerful tool to reveal harmony of components in mixtures, extract information related to the role of each of them, and help in decision-making process regarding choosing the appropriate recipes.