Oil spill problems and sustainable response strategies through new technologies

Crude oil and petroleum products are widespread water and soil pollutants resulting from marine and terrestrial spillages. International statistics of oil spill sizes for all incidents indicate that the majority of oil spills are small (less than 7 tonnes). The major accidents that happen in the oil industry contribute only a small fraction of the total oil which enters the environment. However, the nature of accidental releases is that they highly pollute small areas and have the potential to devastate the biota locally. There are several routes by which oil can get back to humans from accidental spills, e.g. through accumulation in fish and shellfish, through consumption of contaminated groundwater. Although advances have been made in the prevention of accidents, this does not apply in all countries, and by the random nature of oil spill events, total prevention is not feasible. Therefore, considerable world-wide effort has gone into strategies for minimising accidental spills and the design of new remedial technologies. This paper summarizes new knowledge as well as research and technology gaps essential for developing appropriate decision-making tools in actual spill scenarios. Since oil exploration is being driven into deeper waters and more remote, fragile environments, the risk of future accidents becomes much higher. The innovative safety and accident prevention approaches summarized in this paper are currently important for a range of stakeholders, including the oil industry, the scientific community and the public. Ultimately an integrated approach to prevention and remediation that accelerates an early warning protocol in the event of a spill would get the most appropriate technology selected and implemented as early as possible-the first few hours after a spill are crucial to the outcome of the remedial effort. A particular focus is made on bioremediation as environmentally harmless, cost-effective and relatively inexpensive technology. Greater penetration into the remedial technologies market depends on the harmonization of environment legislation and the application of modern laboratory techniques, e.g. ecogenomics, to improve the predictability of bioremediation

Synthesis and Characterization of Group 4 Fluorinated Bis(amidinates) and Their Reactivity in the Formation of Elastomeric Polypropylene

Bis­(amidinate) titanium and zirconium bis­(dimethylamido) complexes were prepared, and the dynamic behavior of the titanium complex containing perfluorinated amidinate ligand (<b>11</b>) was studied in detail. The variable-temperature NMR revealed the presence of two species in solution, in line with the different connection modes of the ligand to the metal center. The resulting complexes were tested as catalysts in the polymerization of propylene, and the resulting polymers were consistent with elastomeric high-molecular-weight atactic polypropylenes

Titanium Bis(amidinates) Bearing Electron Donating Pendant Arms as Catalysts for Stereospecific Polymerization of Propylene

A series of titanium bis­(amidinate) complexes containing pendant arms as one of the amidinate N substituents have been prepared and studied in the polymerization of propylene after their activation with MAO and other cocatalysts. The type of pendant arm greatly influences the reactivity and stereospecificity of the resulting polymers. The effect of the cocatalyst nature, its amount, and the time of the reaction have a dramatic effect on the reactivity of a titanium bis­(amidinate) bis­(dimethylamido) precatalyst containing a furyl group at the pendant arm

Synthesis of Terpyridine-Terminated Amphiphilic Block Copolymers and Their Self-Assembly into Metallo-Polymer Nanovesicles

Polystyrene-b-polyethylene glycol (PS-b-PEG) amphiphilic block copolymers featuring a terminal tridentate N,N,N-ligand (terpyridine) were synthesized for the first time through an efficient route. In this approach, telechelic chain-end modified polystyrenes were produced via reversible addition-fragmentation chain-transfer (RAFT) polymerization by using terpyridine trithiocarbonate as the chain-transfer agent, after which the hydrophilic polyethylene glycol (PEG) block was incorporated into the hydrophobic polystyrene (PS) block in high yields via a thiol-ene process. Following metal-coordination with Mn2+, Fe2+, Ni2+, and Zn2+, the resulting metallo-polymers were self-assembled into spherical, vesicular nanostructures, as characterized by dynamic light scattering and transmission electron microscopy (TEM) imaging

Synthesis and Structure of Group 4 Symmetric Amidinate Complexes and Their Reactivity in the Polymerization of α‑Olefins

The steric properties of various nitrogen substituents on amidines were tuned in order to obtain group 4 mono- and bis­(amidinate) dimethylamido or chloride complexes. The amidinate dimethylamido and chloride complexes were prepared, and their solid-state as well as their solution-state structures were studied. After the activation by MAO, these complexes were tested in the polymerization of propylene and ethylene. A noticeable influence of the amidine carbon and nitrogen substituents on the activity of the catalyst and properties of the obtained polymer was observed. Further, a plausible mechanism for the ethylene polymerization process is presented taking into account a combination of ESR-C₆₀ and MALDI-TOF experiments, shedding light on the nature of the catalytic species

Asymmetric Bis(formamidinate) Group 4 Complexes: Synthesis, Structure and Their Reactivity in the Polymerization of α‑Olefins.

A series of asymmetric formamidine ligands bearing different substituents with various steric and electronic properties on the nitrogen of the N–C–N motif were synthesized. Group 4 bis­(formamidinate) dimethylamido, chloride, and benzyl complexes were studied using these asymmetric ligands and their solid-state structures and their behavior in solution were determined. These complexes were activated with MAO (methylalumoxane) or a combination of cocatalysts and tested in the polymerization of ethylene and propylene. A noticeable influence of the formamidine nitrogen substituents on the activity of the catalyst and properties of the obtained polymers was observed. Further, a plausible mechanism for the polymerization of propylene is presented derived from a combination of ESR-C₆₀ and MALDI-TOF trapping experiments which shed light on the nature of the active catalytic species