Reactive organic compounds are precursors to secondary organic aerosols, which are a major contributor to environmental pollutants negatively impacting human health outcomes. Additionally, the loss of latter organic compounds is closely related to aging in the binder used in asphalt pavements, which increases the cost and resources needed to maintain the pavements.
Recently, asphalt has been identified as an important source of hazardous emissions. Asphalt-related emissions accounted for more secondary organic aerosols (SOAs) than the combined emissions of gas and diesel on-road vehicles. Emissions were shown to include hydrocarbons and sulfur/oxygen-containing compounds, which increased sharply with increasing UV radiation. There is a need for technology that can help to safely reduce asphalt-related emissions, especially in urban areas that are exposed to hot summers with intense UV radiation.
Researchers at Arizona State University have developed BIGSS (Bio-Grafted Silica Sink), which enables a novel method to address asphalt-related emissions. BIGSS includes a built-in mechanism using an engineered bio-grafted porous material to prevent the emissions of VOCs from asphalt surfaces to the air. The porous silica nano-filler is built from pristine silica nanoparticles grafted with bio-oils derived from woody biomass, animal waste, vegetable, and seed wastes. The aromatic nature of the bio-oils as well as their polar components such as oxygen-containing functional groups leads to the formation of a very stable complex of bio-grafted silica. The bio-modified nano-filler acts as a sink to trap the candidate volatile molecules, preventing the emission of these volatiles to the air. The absorptive activity of bio-grafted silica was notably higher (up to 63%) than that of pristine silica.
- Reducing VOC emissions from bitumen and asphalt-surfaced areas
- Low-cost modifier to prevent mass loss in asphalt
- Anti-aging bitumen modifier
Benefits & Advantages
- Non-hazardous & environmentally friendly materials
- Cost-effective materials & method (bio-oil derived from waste biomasses)
- Prevents VOC emissions from asphalt-surfaced areas
- Increased service life of asphalt roads
- Increased absorptive activity compared to pristine silica (up to 63%)