Eco Synthesis of Layered and Bubbly Graphene from Natural Surfactants: Smartphone-Based Examination of Sound Attenuation Capability

Here, we propose a novel approach for synthesizing graphene flakes using graphite and natural surfactants. We synthesized few-layer graphene using Jatropha Carcus and Acacia Concinna as surfactants in the liquid phase exfoliation method in water. Raman spectroscopy revealed an ID/IG ratio of ≈2.54 for graphene extracted from Jatropha Carcus (JG) and ≈0.79 for graphene extracted from Acacia Concinna (AG), along with a higher number of deconvoluted peaks in the 2D band for AG. These findings suggest a higher number of graphene layers and a lower defect density in the AG sample compared to the JG sample. It is also noticed that AG offers bubblygraphene morphology. These flakes are further transformed into graphene foam. The AG graphene foam material (AGFM) presents decorated porosity on the melamine base with larger pore diameters (1 μm to 2 μm), whereas JG foam material (JGFM) has flake like morphology on it. These morphological variations impact the produced foams’ ability to reduce acoustic sound. A cost-effective smart phone-based measurement system developed in our laboratory was employed to assess the sound absorption properties of the synthesized foam materials. Results demonstrate that AGFM effectively attenuates sound (≈99%) across a broad frequency spectrum, ranging from 300 Hz to 6000 Hz. Melamine foam material has minor/negligible sound absorption, while JGFM only demonstrates noticeable sound absorption at frequencies higher than 2000 Hz (up to 6000 Hz). Our results indicate that AGFM is a good contender for advanced acoustic applications owing to its greater graphene layer thickness and improved porosity, which makes it effective for applications needing better sound attenuation.