Polyisobutylene Oligomers as Tools for Iron Oxide Nanoparticle Solubilization

Abstract

A series of terminally functionalized polyisobutylene (PIB) derivatives were synthesized and tested as agents for magnetic nanoparticle solubilization. PIB-bound catechol was found to be the best functionalized polyolefin at effecting such solubilization based on UV−vis spectroscopic absorbance measurements and thermogravimetric analysis. The PIBmodified magnetic nanoparticles obtained from grafting reactions contain up to 32 wt % of MNPs. They easily disperse in nonpolar and modestly polar organic solvents. The high loading (>50 wt %) of the PIB-modified magnetic nanoparticles even in alkane solvents makes the resulting solutions magnetically susceptible. This was illustrated by preliminary work where PIB-modified MNPs formed solutions with heptane that could be magnetically separated from water. These PIB-modified magnetic nanoparticles were also shown to be highly soluble in low melting polyethylene waxes and in liquid poly(α-olefin)s.

Solubilization of silica nanoparticles in alkanes and poly(α‐olefin)s by functionalized polyisobutylene oligomers

“…Our success using polyisobutylene (PIB) to solubilize magnetic nanoparticles (MNPs) in heptane and nonpolar polymers suggested to us that PIB could also be used to solubilize silica nanoparticles in nonpolar solvents like heptane and poly(α‐olefin)s (PAOs). The results below discuss covalent modification of SiNPs using unfunctionalized SiNPs with PIB terminated with trialkoxysilane groups, thio‐ene chemistry of PIB alkenes with thiol‐containing SiNPs, and reactions of aminated SiNPs with activated derivatives of carboxylic acid‐terminated PIB.…”

Sustainable Hydrocarbon Oligomer Solvent Systems for Sequestration of Trace Organics from Water

“…To address the issue of insufficient sequestration levels for polar organics, we explored modifying PAO with a PAO‐phase‐anchored cosolvent to generate a sequestering phase that contained molecular‐recognition elements. Our experience with PIB‐bound dyes, ligands, catalysts, and polar nanoparticles is that hydrocarbon oligomeric solvents are very effective at phase‐anchoring PIB‐bound polar species . Thus, we reasoned that a PIB with a hydrogen‐bonding terminal catechol group (Figure ) could be phase‐anchored in PAO and could be used to facilitate sequestration of polar groups in PAO because the ability of catechol to form H‐bonds.…”

“…Our experience with PIB-bound dyes, ligands, catalysts, and polar nanoparticles is that hydrocarbon oligomeric solvents are very effective at phase-anchoring PIB-bound polar species. [9,[16][17][18] Thus, we reasoned that aP IB with ah ydrogen-bonding terminal catecholg roup ( Figure 2) could be phase-anchored in PAOa nd couldb eu sed to facilitate sequestration of polar groups in PAOb ecause the ability of catechol to form H-bonds. This benzene( 900) [a] 7.0 99 hexane (800) [a,d] < 0.1 > 99 benzene( 24) [b] < 0.1 > 99 dichloromethane (1450) [b] 72 95 benzene( 550) [c] 3.4 99 benzene( 450) [d] 8.1 98 1,2-dichloroethane (650) [c] 40 94 1,4-dichlorobenzene (17) [c] < 0.1 > 99 dichloromethane (7000) [c] 350 > 99 THF (11100) [c] 7700 (2820) [e] 30 (76) [e] THF (2820) [c] 330 [e] 88 [e] triethylamine (15 000) [c] 4500 (600) [ [a] Sequestration was performedb ym ixing the D 2 Os olution (3.5 g) containingt he organic impurity with the PAO 432 (1.5 g) with av ortexm ixer for 1min.…”

Block copolymers derived from polyisobutylene oligomers

“…These materials’ phase selective solubility in alkane solvents like heptane and poly(α‐olefin)s (PAOs) makes these oligomeric hydrocarbon derivatives excellent phase anchors for immobilization of ligands and catalysts . Such functional polyisobutylene derivatives are also useful in that they make otherwise insoluble materials like phthallocyanines, inorganic clusters, and nanoparticles soluble in alkane solvents and in polyolefins . Here, we explore chemistry to modify the properties of PIB exploring possible routes to block copolymers using the functional groups of commercially available alkene‐terminated PIB oligomers as handles to couple polar monomers to these preexisting PIB oligomers.…”