Microalgae are a potential candidate for biofuel production and environmental treatment because of their specific characteristics (e.g. fast growth, carbon neutral, and rich lipid accumulations). However, several primary bottlenecks still exist in current technologies, including low biomass conversion efficiency, bio-invasion from the external environment, limited or costly nutrient sources, and high energy and capital input for harvest, and stalling its industrial progression. Coupling biofuel production with environmental treatment renders microalgae a more feasible feedstock. This review focuses on microalgae biotechnologies for both bioenergy generation and environmental treatment (e.g. CO₂ sequestration and wastewater reclamation). Different intelligent technologies have been developed, especially during the last decade, to eliminate the bottlenecks, including mixotrophic/heterotrophic cultivation, immobilization, and co-cultivation. It has been realized that any single purpose for the cultivation of microalgae is not an economically feasible option. Combinations of applications in biorefineries are gradually reckoned to be necessary as it provides more economically feasible and environmentally sustainable operations. This presents microalgae as a special niche occupier linking the fields of energy and environmental sciences and technologies. The integrated application of microalgae is also proven by most of the life-cycle analysis studies. This study summarizes the latest development of primary microalgal biotechnologies in the two areas that will bring researchers a comprehensive view towards industrialization with an economic perspective.

An intrinsic flame retardant silicone rubber was successfully prepared which possessed excellent self-extinguishing properties, high transparency and better mechanical properties.

A novel hybrid flame retardant combining graphene oxide (GO) with long-chain phosphaphenanthrene was fabricated via surface grafting reaction. Taking advantageous of the double barrier effects, including the physical shield contributed by graphene nanoplates during the initial stage and the chemical char contributed by phosphaphenanthrene during the later stage, greatly decreased the release rate of decomposed volatiles from the resin, as well as minimized the release of oxygen and combustion heat. Hence, such hybrid flame retardant can overcome the shortcomings of early acid catalyzed degradation effects caused by conventional flame retardants containing phosphorus. Satisfactory flame retardance was achieved (UL94 V-0 rating) with only 4% addition of the hybrid flame retardant to the epoxy resin laminate. Due to the long-chain and bulky phosphaphenanthrene groups, the interlayer attractive forces of the modified GO were effectively weakened, thus favoring the exfoliation and dispersion of graphene sheets. As a result, the incorporation of the flame retardant slightly enhanced the mechanical properties of the polymer composites, rather than deteriorating them, as occurs with traditional additive flame retardants. As a potential application for graphene, it is believed that the reported hybrid flame retardant has promising future prospect.