Polymer Waste Valorization into Advanced Carbon Nanomaterials for Potential Energy and Environment Applications

The rise in universal population and accompanying demands have directed toward an exponential surge in the generation of polymeric waste. The estimate predicts that world-wide plastic production will rise to ≈590 million metric tons by 2050, whereas 5000 million more tires will be routinely abandoned by 2030. Handling this waste and its detrimental consequences on the Earth's ecosystem and human health presents a significant challenge. Converting the wastes into carbon-based functional materials viz. activated carbon, graphene, and nanotubes is considered the most scientific and adaptable method. Herein, this world provides an overview of the various sources of polymeric wastes, modes of build-up, impact on the environment, and management approaches. Update on advances and novel modifications made in methodologies for converting diverse types of polymeric wastes into carbon nanomaterials over the last 5 years are given. A remarkable focus is made to comprehend the applications of polymeric waste-derived carbon nanomaterials (PWDCNMs) in the CO2 capture, removal of heavy metal ions, supercapacitor-based energy storage and water splitting with an emphasis on the correlation between PWDCNMs' properties and their performances. This review offers insights into emerging developments in the upcycling of polymeric wastes and their applications in environment and energy.

In-situtemperature-dependent sheet resistance study of Cu films in oxygen ambient for heterogeneous integrations

Controlling and preventing Cu oxidation is crucial for improving the performance and reliability of Cu-Cu bonding. Ni-B films were selectively deposited on Cu films to block the Cu oxidation. The resistivity changes of the Cu films in N2and O2ambient were measured by using a four-point probe in thein situtemperature-dependent resistance measurements at the temperature from room temperature to 400 °C. The resistivity changes of the 100 nm thick Cu films without Ni-B increased rapidly at a higher temperature (284 °C) in the O2ambiance. The change of resistivity-increase of 100 nm thick Cu with ∼50 nm thick Ni-B (top) film was lower than the Cu films without Ni-B films due to the blocking diffusion of O2atoms by the Ni-B films. The resistivity-change and oxidation barrier properties were studied using scanning electron microscopy, FIB, transmission electron microscopy, EDX, and secondary ion mass spectroscopy tools. The proposed article will be helpful for the upcoming advancement in Cu-Cu bonding using selected-area deposition.

Thermal, Mechanical, and Electrical Stability of Cu Films in an Integration Process with Photosensitive Polyimide (PSPI) Films

Photosensitive polyimides (PSPIs) have been widely developed in microelectronics, which is due to their excellent thermal properties and reasonable dielectric properties and can be directly patterned to simplify the processing steps. In this study, 3 μm~7 μm thick PSPI films were deposited on different substrates, including Si, 50 nm SiN, 50 nm SiO2, 100 nm Cu, and 100 nm Al, for the optimization of the process of integration with Cu films. In situ temperature-dependent resistance measurements were conducted by using a four-point probe system to study the changes in resistance of the 70 nm thick Cu films on different dielectrics with thick diffusion films of 30 nm Mn, Co, and W films in a N2 ambient. The lowest possible change in thickness due to annealing at the higher temperature ranges of 325 °C to 375 °C is displayed, which suggests the high stability of PSPI. The PSPI films show good adhesion with each Cu diffusion barrier up to 350 °C, and we believe that this will be helpful for new packaging applications, such as a 3D IC with a Cu interconnect.

Recent progress in energy, environment, and electronic applications of MXene nanomaterials

Since the discovery of graphene, two-dimensional (2D) materials have gained widespread attention, owing to their appealing properties for various technological applications. Etched from their parent MAX phases, MXene is a newly emerged 2D material that was first reported in 2011. Since then, a lot of theoretical and experimental work has been done on more than 30 MXene structures for various applications. Given this, in the present review, we have tried to cover the multidisciplinary aspects of MXene including its structures, synthesis methods, and electronic, mechanical, optoelectronic, and magnetic properties. From an application point of view, we explore MXene-based supercapacitors, gas sensors, strain sensors, biosensors, electromagnetic interference shielding, microwave absorption, memristors, and artificial synaptic devices. Also, the impact of MXene-based materials on the characteristics of respective applications is systematically explored. This review provides the current status of MXene nanomaterials for various applications and possible future developments in this field.

Regression of coronary atherosclerosis through healthy lifestyle in coronary artery disease patients--Mount Abu Open Heart Trial

AIMS

To evaluate the efficacy of a unique healthy and happy lifestyle (HLS) program in regression of coronary atherosclerosis and reduction in cardiac events in an open trial.

METHODS

One hundred and twenty three angiographically documented moderate to severe coronary artery disease (CAD) patients were administered HLS comprising of low-fat, high-fiber vegetarian diet, moderate aerobic exercise and stress-management through Rajyoga meditation. Its most salient feature was training in self-responsibility (heal+thy) and self-empowerment through inner-self consciousness (swasth; swa=innerself, sth=consciousness) approach using Rajyoga meditation. Following a seven day in-house sojourn, patients were invited for six month follow-up for reassessment and advanced training. At the end of two years, all patients were asked to undergo repeat angiography.

RESULTS

Three hundred and sixty coronary lesions were analysed by two independent angiographers. In CAD patients with most adherence, percent diameter stenosis regressed by 18.23 +/- 12.04 absolute percentage points. 91% patients showed a trend towards regression and 51.4% lesions regressed by more than 10 absolute percentage points. The cardiac events in coronary artery disease patients were: 11 in most adherence, and 38 in least adherence over a follow-up period of 6.48 yrs. (risk ratio; most vs least adherence: 4.32; 95% CI: 1.69-11.705; P < 0.002).

CONCLUSION

Overall healthy changes in cardiovascular, metabolic and psychological parameters, decline in absolute percent diameter coronary stenosis and cardiac events in patients of CAD were closely related to HLS adherence. However, more than 50% adherence is essential to achieve a significant change.

Dermatoglyphics in nasobronchial allergic disorders

Fifty persons having nasobronchial allergy diagnosed by a positive skin test were compared with age and sex matched normal individuals for dermatoglyphic palmer patterns. The palmer prints were obtained on white art paper using Kores duplicating ink. In female patients, total number of whorls was less, more so on digit IV of left hand. Digit V of right hand had low frequency of ulnar loops, the d-t ridge count was low. In male patients, ulnar loops were less frequent on digit III of right hand. Total finger ridge count was less in both sexes. High frequency of arches was observed in female patients and in total. Digit V of left hand in females and in total patients revealed high frequency of arches. a-b ridge count was high in males and in total patients.