Products

µ-Sq Beads

or otherwise known as PMPS Particles

Description:

µ-Sq beads are prepared in a one-pot polycondensation reaction and precipitate as micrometer sized solid spherical particles made of poly(1-methylpyrrol-2-ylsquaraine).

They are black in colour, both thermally and chemically robust (for an organic chemical species), and have an internal amorphous porous network that can absorb a range of chemical entities.

µ-Sq beads have been developed as carriers for chemical additives in thermoplastics, rubbers, and paints / lacquers.

Physical properties:

Physical State:Solid
Colour:Black
Odour:None reported
Solubility in Water:Insoluble
Specific Gravity/Density:1.3 - 1.6 g.cm^-3

Particle size (diameter) range:1.3 - 4.0 µm
Average particle size:1.92 ± 0.05 µm

Mean nominal rupture stress:493 ± 113 MPa
Mean deformation at rupture:+ 65% initial diameter

Chemical Formula:

Thermogravimetric analysis:                                 

Surface area and pore size analysis:

Surface area and pore size cannot be determined using standard N₂ absorption techniques.

The following TEM image shows a slice of a bead that had been soaked in a methanolic solution containing containing uranyl acetate followed by an aqueous solution of lead citrate. The dark patches highlight some of the larger internal pores within the bead.

Additional information:

µ-Sq beads are prepared and supplied as aggregated clusters in a dry powder. Aggregate size distribution is shown below.

Absorption characteristics have been examined for all of the metal elements in the periodic table from lithium to bismuth, including the lanthanides, except for beryllium, tellurium and the radioactives.

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Cross-sectional absorption profiles for beads containing both uranium atoms and chlorine atoms indicates that absorption is higher in the surface regions, as indicated by the following images.

Shakiela Begum, Ian P. Jones, Chengge Jiao, Daniel E. Lynch and Jon A. Preece, “Characterisation of hollow Russian doll microspheres”, J. Mater. Sci., 2010, 45, 3697-3706.

Daniel E. Lynch, Yasser Nawaz and Thor Bostrom, “The Preparation of Sub-Micrometer Silica Shells using Poly(1-methylpyrrol-2-ylsquaraine)”, Langmuir, 2005, 21, 6572-6575.

Daniel E. Lynch, Uwe Geissler and Karl A. Byriel, “An investigation into the electrical conduction properties of poly(oligo(1-methylpyrrol-2-yl)squaraine)s”, Synth. Met., 2001, 124, 385-391 for x-ray powder diffraction and electrical insulation data.