Amino acids are organic molecules that play a crucial role in forming proteins and various metabolic processes. Structurally, they contain an amino group (–NH2) and a carboxylic acid group (–COOH). The name "amino acid" is derived from these functional groups. Whether an amino acid behaves as acidic or basic depends on the pH of the environment and the nature of its side chain (R-group). At a neutral pH (around 7), amino acids exist in their zwitterionic form, where the amino group is protonated (–NH3+) and the carboxyl group is deprotonated (–COO–), giving it both positive and negative charges. The acidic nature of amino acids can be attributed to the carboxyl group, which can donate a proton to the solution. However, the overall charge and acidity/basicity of an amino acid in solution also depend on the side chain's properties. Some amino acids have side chains that can be acidic (like glutamate and aspartate, which have additional carboxyl groups) or basic (like lysine and arginine, which have amine groups in their side chains). Therefore, whether an amino acid acts as an acid depends on its environment and specific characteristics.

Polypropylene (PP) is a thermoplastic polymer widely known for its resistance to various chemical solvents, bases, and acids, making it a popular choice for containers and pipework for chemicals. Its structure, characterized by a semi-crystalline nature, contributes to its physicochemical properties. Specifically, regarding oil absorption, polypropylene's hydrophobic nature allows it to effectively repel water while having the affinity to absorb oils and other non-polar substances. This characteristic is utilized in applications such as oil spill clean-ups, industrial oil/water separators, and filters for removing oil from water. The efficiency of polypropylene in oil absorption is influenced by the surface area, pore size of the material, and the viscosity of the oil. Advancements in material science have aimed at enhancing these properties through modifications at the molecular or composite level to increase oil absorption rates and capacities. For instance, creating polypropylene-based absorbents with larger surface areas or specific functional groups can improve oil affinity and uptake. Accordingly, polypropylene remains a material of choice for environmental cleanup efforts and industrial applications requiring efficient oil separation and absorption.

Teflon coating, made from polytetrafluoroethylene (PTFE), is mainly criticized for its potential health and environmental risks. When overheated, Teflon-coated cookware releases toxic fumes that can cause flu-like symptoms in humans and may be fatal to birds. Moreover, the manufacturing process of Teflon involves perfluorooctanoic acid (PFOA), a substance linked to cancer and other health issues, although newer formulations are PFOA-free. The breakdown of these non-stick coatings also leads to their particles mixing with food and being ingested over time, raising concerns about long-term health effects. While Teflon provides convenience and non-stick benefits, alternatives such as stainless steel, cast iron, or ceramic coatings are recommended for safer cooking.