High performance polymer, Polyether Ether Ketone (PEEK) (service temperature À250C to þ300 C, tensile strength: 120 MPa) is gaining significant interest in aerospace and automotive industries. In this investigation, attention is given to understand adhesion properties of PEEK, when surface of the PEEK is modified by two different plasma processes (i) atmospheric pressure plasma and (ii) low pressure plasma under DC Glow Discharge. The PEEK sheets are fabricated by ultra high temperature resistant epoxy adhesive (DURALCO 4703, service temperature À260 C to þ350 C). The surface of the PEEK is modified through atmospheric pressure plasma with 30 and 60 s of exposure and low pressure plasma with 30, 60, 120, 240, and 480 s of exposure. It is observed that polar component of surface energy leading to total surface energy of the polymer increases significantly when exposed to atmospheric pressure plasma. In the case of low pressure plasma, polar component of surface energy leading to total surface energy of the polymer increases with time of exposure up to 120 s and thereafter, it deteriorates with increasing time of exposure. The fractured surface of the adhesively bonded PEEK is examined under SEM. It is observed that unmodified PEEK fails essentially from the adhesive to PEEK interface resulting in low adhesive bond strength. In the case of surface modified PEEK under atmospheric pressure plasma, the failure is entirely from the PEEK and essentially tensile failure at the end of the overlap resulting in significant increase in adhesive bond strength.

Abstract-In this work, the effect of low pressure plasma and atmospheric pressure plasma treatment on sur face properties and adhesion characteristics of high performance polymer, Polyether Ether Ketone (PEEK) are investigated in terms of Fourier Transform Infrared Spectroscopy (FTIR), X ray photoelectron spectros copy (XPS), and Atomic Force Microscopy (AFM). The experimental results show that the PEEK surface treated by atmospheric pressure plasma lead to an increase in the polar component of the surface energy, resulting in improving the adhesion characteristics of the PEEK/Epoxy adhesive system. Also, the roughness of the treated surfaces is largely increased as confirmed by AFM observation. These results can be explained by the fact that the atmospheric pressure plasma treatment of PEEK surface yields several oxygen function alities on hydrophobic surface, which play an important role in increasing the surface polarity, wettability, and the adhesion characteristics of the PEEK/Epoxy adhesive system.

Self-healing polymers (SHP) are the polymers that have the capability to recover the material from any physical damage by responding to the damages or cracks in the material and heal the same. This self-healing technology gives the polymers ability to recover from the cracks at an early stage by preventing them from any catastrophic failures, which increases the scope of applications of these materials. This review article highlights the key points on extrinsic self-healing polymer and intrinsic self-healing polymer by comparing their healing efficiency, advantages, disadvantages, and challenges in the prospect of their future development as well as their possible applications in space industry and construction of roads.

Background Yashada bhasma has been found to be very useful for the treatment of ailments like diabetes, eye disorder, urinary disorder etc. Since bhasma is a metallic preparation, so to prove its non-toxicity; modern standardization of the prepared samples is a must apart from other organoleptic tests as mentioned in the ancient text. Objectives The present study is aimed to synthesize bio-compatible Yashada bhasma from bio-incompatible zinc metal. Further, comparative study of their chemical and physical properties through some quality control tests, physico-chemical tests and modern tests like XRD, DLS, Zeta potential, SEM and EDAX are carried out. Materials and methods Yashada bhasma is prepared by a three step process i.e. Shodhan, Jarana and Marana . The inclusion of plant extracts and herbs during calcination process enhances its medicinal qualities, and reduces it to a nano size. Results The XRD analysis of Yashada bhasma shows hexagonal ZnO crystalline phase whereas the raw metal confirms the presence of crystallite Zinc metal. DLS shows reduction in particle size of Yashada Bhasma (339.8 nm) as compared to raw metal (2063 nm) and this reduction is further supported by SEM which shows the particle size of Yashada bhasma (324 nm) and raw metal (1-2μ). The zeta potential value confirms the stability of Yashada bhasma . EDAX revealed difference in concentration of Zinc and Oxygen in both the samples. Conclusion An effort has been made to characterize the preparation of Yashada bhasma using sophisticated analytical tools as a step towards standardization of the bhasma. The results help in scientifically establishing the findings in line with the principle of Ayurveda.

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