A comparative study of organic solvents, ionic liquids, surfactants and acids for liquid phase exfoliation of graphene

Graphene is the most widely investigated carbon nanomaterial having two-dimensional honeycomb lattice structure. Recently, it has attracted worldwide attention due to its remarkable electrical, thermal, mechanical, chemical and optical properties, which are highly suitable for various electronic device applications. Various methods of graphene synthesis have been utilized for the production of graphene each having its own advantages and disadvantages. Liquid phase exfoliation method uses top-down approach and has the advantages of being environment friendly, facile and economically viable. Liquid phase exfoliated graphene is highly suitable for making thin films for their potential applications in electronic devices such as thin films transistors, transparent electrodes, light-emitting diodes, supercapacitors, etc. In this paper, a comparative study of different exfoliation medium used for liquid phase exfoliation of graphene such as organic solvents, ionic liquids, surfactants, polymers and acids are described. Because of the usually low concentration of graphene (< 0.01 mg/mL) obtained from liquid phase exfoliation method, research has been done for enhancing the concentration. Recent progress made in enhancing graphene concentration in organic solvents by adding various additives is reported here. Finally, we discuss the challenges and future prospects of improving liquid phase exfoliation of graphene for modern electronics devices

Terahertz Detectors (THzDs): Bridging the Gap for Energy Harvesting

It is indispensable to integrate electronics with environment for better lives. Huge amount of solar energy, dark energy, and unused microwave energy is untapped till now due to insufficient availability of high frequency THz detectors. The difference between THz wave detection and THz electric field detection must be clear. THz wave detection connects the detection of explosives, drugs, astronomy, metals, and imaging applications, etc. On the other hand, THz electric field detection involves the conversion of electromagnetic (EM) radiations to usable DC power. The optimum choice of detectors for energy harvesting is a highly diverse area. The latter part is concentrated on the nonlinear behavior of the incoming radiations and has been highlighted also. In this chapter, metal‐insulator‐metal (MIM) diode detectors have been explored to become a best choice for high frequency detectors

A facile approach to fabricate graphene based piezoresistive strain sensor on paper substrate

Sensors, FETs and chemi resistors are few of the devices which show potential in the area of flexible electronics for health monitoring applications. In the present work, piezoresistive strain sensors based on graphite and graphene on cellulose paper substrate has been reported. Graphite sensor has been fabricated by rubbing pencil on paper and graphene sensor by directly coating graphene ink using paint brush. The resistance of the fabricated sensor increases with outwards bending and vice-versa, further the piezoresistive effect has also been evaluated by applying variable longitudinal stress. A comparative study of gauge factor (GF) depending upon different type of strains has been presented and it has been observed that the GF of graphene piezoresistive strain sensor decreases with increase in number of layers, the GF for graphene sensor is higher as compared to graphite sensor. Fabricated piezoresistive strain sensors may find applications as human body motion detection, gait analysis etc

Comparative analysis of efficient diode design for terahertz wireless power transmission system

The wireless power transmission (WPT) technology is an extension of wireless communication. The physics of WPT and wireless communication are related, but WPT is distinct from wireless transmission for transferring information (such as radio and mobile phones etc.), where the percentage of the power that is received is only important if it becomes too low to successfully recover the signal. With WPT, the efficiency is a more critical parameter and this creates important differences in these technologies. This paper presents the wireless power transmission (WPT), from past work to most recent accomplishments including recent developments, potential approaches and factors responsible for designing most critical rectifying diodes operating at terahertz/petahertz frequencies

A comparative study of organic solvents, ionic liquids, surfactants and acids for liquid phase exfoliation of graphene

322-333Graphene is the most widely investigated carbon nanomaterial having two-dimensional honeycomb lattice structure. Recently, it has attracted worldwide attention due to its remarkable electrical, thermal, mechanical, chemical and optical properties, which are highly suitable for various electronic device applications. Various methods of graphene synthesis have been utilized for the production of graphene each having its own advantages and disadvantages. Liquid phase exfoliation method uses top-down approach and has the advantages of being environment friendly, facile and economically viable. Liquid phase exfoliated graphene is highly suitable for making thin films for their potential applications in electronic devices such as thin films transistors, transparent electrodes, light-emitting diodes, supercapacitors, etc. In this paper, a comparative study of different exfoliation medium used for liquid phase exfoliation of graphene such as organic solvents, ionic liquids, surfactants, polymers and acids are described. Because of the usually low concentration of graphene (< 0.01 mg/mL) obtained from liquid phase exfoliation method, research has been done for enhancing the concentration. Recent progress made in enhancing graphene concentration in organic solvents by adding various additives is reported here. Finally, we discuss the challenges and future prospects of improving liquid phase exfoliation of graphene for modern electronics devices

A RETROSPECTIVE STUDY OF ANTENATAL TESTING IN WOMEN WITH REPRODUCTIVE AGE GROUP TRIBAL AREA

Objective: This retrospective study aimed to investigate the utilization and outcomes of antenatal testing among women of reproductive age in tribal areas. The study aimed to assess the extent to which antenatal testing services are utilized, identify potential barriers, and propose strategies to enhance healthcare delivery for this vulnerable population. Methods: Medical records of tribal women receiving antenatal care during a specific period were retrospectively examined. Data on antenatal tests, demographic characteristics, and geographical accessibility were collected. Statistical analysis, including chi-square tests and t-tests, was performed. Results: Age distribution analysis showed a majority of individuals in the 20-30 y age range. Hemoglobin levels were significantly higher in the "Muslim" group compared to the "Non-Muslim" group. No significant difference was found in total leukocyte count (TLC) and platelet levels between the two groups. Blood group distribution analysis revealed variations between the groups, with a borderline significant difference. Sickle cell status showed a significant difference, with a higher percentage of positive cases in the "NM" group. Conclusion: This study provides insights into the utilization and outcomes of antenatal testing in tribal areas. It highlights the need for targeted interventions to overcome barriers to access and improve antenatal care delivery in marginalized populations. The findings contribute to the existing literature, guiding policymakers and healthcare providers in developing equitable healthcare strategies for tribal women