Littérature scientifique sur le sujet « Self-healing master curve »

Jatropha oil-based polyol (JOL) was prepared from crude Jatropha oil via an epoxidation and hydroxylation reaction. During the isocyanation step, two different types of diisocyanates; 2,4-toluene diisocyanate (2,4-TDI) and isophorone diisocyanate (IPDI), were introduced to produce Jatropha oil-based polyurethane acrylates (JPUA). The products were named JPUA-TDI and JPUA-IPDI, respectively. The success of the stepwise reactions of the resins was confirmed using 1H nuclear magnetic resonance (NMR) spectroscopy to support the Fourier-transform infrared (FTIR) spectroscopy analysis that was reported in the previous study. For JPUA-TDI, the presence of a signal at 7.94 ppm evidenced the possible side reactions between urethane linkages with secondary amine that resulted in an aryl-urea group (Ar-NH-COO-). Meanwhile, the peak of 2.89 ppm was assigned to the α-position of methylene to the carbamate (-CH2NHCOO) group in the JPUA-IPDI. From the rheological study, JO and JPUA-IPDI in pure form were classified as Newtonian fluids, while JPUA-TDI showed non-Newtonian behaviour with pseudoplastic or shear thinning behaviour at room temperature. At elevated temperatures, the JO, JPUA-IPDI mixture and JPUA-TDI mixture exhibited reductions in viscosity and shear stress as the shear rate increased. The JO and JPUA-IPDI mixture maintained Newtonian fluid behaviour at all temperature ranges. Meanwhile, the JPUA-TDI mixture showed shear thickening at 25 °C and shear thinning at 40 °C, 60 °C and 80 °C. The master curve graph based on the shear rate for the JO, JPUA-TDI mixture and JPUA-IPDI mixture at 25 °C, 40 °C, 60 °C and 80 °C was developed as a fluid behaviour reference for future storage and processing conditions during the encapsulation process. The encapsulation process can be conducted to fabricate a self-healing coating based on a microcapsule triggered either by air or ultra-violet (UV) radiation.

Fracture is a disruption of the normal discontinuity of bone and causes the surrounding tissue to be disrupted. Management of fractures is generally divided into recognition, reduction, retention, and rehabilitation. Exercises in the postoperative fracture patient rehabilitation program require patience and take a long time to achieve maximum cure. Nurses' therapeutic action in helping patients do rehabilitation exercises is by increasing the patient's self-efficacy to be independent in carrying out activities. Efforts to increase self-efficacy can be made through nursing interventions. This literature review aimed to explore the appropriate interventions on improving self-efficacy among postoperative fracture patients. Methods: This study was obtained from 4 databases, namely EBSCO, Key clinical, Willey, and Proquest, using inclusion and exclusion criteria. Results obtained. Decreased self-efficacy can occur in cases that require long action both for the healing process and chronic disease and when taking actions to maintain health, including post-surgery fractures. In conclusion, educational media will make it easier to provide interventions in increasing self-efficacy by paying attention to the factors that affect self-efficacy, namely master experience, vicarious experience, verbal persuasion, and emotional Arousal. The recommendation is that patients need support for adjusting the use of tools in providing education, providing logistics from samples in the application of education through technology media and to parents

The present paper focuses on the rheological behaviour of a series of hydrogels prepared from chitosan and salicylaldehyde. The unusual crosslinking of chitosan with this monoaldehyde was assessed by 1H NMR spectroscopy, which demonstrated the formation of covalent imine bonds. The hydrogels exhibited a super-porous morphology, evidenced by SEM measurements, and the layered supramolecular structure of the hydrogels was sustained by the birefringence texture of the hydrogels, observed by polarized light microscopy (POM). The hydrogel-like behaviour was confirmed by rheologic measurements for the sample containing the highest salicylaldehyde amount. The dynamic flow properties of salicyl-imine-chitosan hydrogels with different crosslinking degrees (NH2/CHO ratios between 2 and 4) were investigated at temperatures in the range of 20–40 °C. The rheological moduli were determined over a wide range of oscillatory frequencies and the experimental results were presented using master curves. In addition, the thixotropic behaviour of the hydrogels based on chitosan and salicylaldehyde was determined and discussed. The measurements of thixotropy were performed by increasing the shear rate to 400 s-1 in an upward sweep, followed by its decreasing in a downward sweep. It was noticed that the hydrogels’ thixotropy increases with an increasing crosslinking degree. In line with this rheological behaviour, the self-healing ability was tested, and it was proved that the hydrogels were able to reshape after applying deformation stress.