Thermo Scientific™ Polyethyleneimine (PEI), M.W. 1,800 (branched, ≥99% purity), is a highly functional polyamine polymer used in a wide range of chemical, biological, environmental, and materials science applications. With its unique branched architecture containing primary, secondary, and tertiary amine groups, this PEI grade offers strong cationic charge density, high reactivity, excellent solubility, and exceptional versatility.

Its moderate molecular weight (~1,800) provides an excellent balance between low viscosity, ease of handling, and sufficient chain length for surface modification, chelation, and polymer functionalisation. Supplied as a colourless to pale yellow liquid with an amine-like odour, this PEI is stable at ambient temperature and suitable for both research and industrial use.

Key Features & Benefits

High-Purity (≥99%) Branched PEI

• Ensures consistent performance across chemical, material, and environmental applications
• High amine density allows strong electrostatic interactions and chelation

Moderate Molecular Weight (M.W. 1,800)

• Lower viscosity than high-MW PEI grades, making it easier to pipette and mix
• Stronger binding and crosslinking capability than very low-MW versions (e.g., 1,200 MW)
• Ideal for coating, complexation, modification, and reaction optimisation

Highly Reactive Cationic Polymer

Useful for:

• Nanoparticle surface coating (gold, silica, magnetite, polymer beads)
• Metal ion chelation & heavy metal removal
• DNA/RNA binding (research-only transfection)
• Crosslinking and functionalising resins & membranes
• Preparing cationic hydrogels & biomaterials
• Adhesion promotion in coatings & composites

Excellent Solubility & Handling Properties

• Completely miscible with water and many polar solvents
• Stable at ambient storage temperature, making storage and shipping convenient

Chemical & Regulatory Information

Physical & Chemical Properties

Applications

1. Nanotechnology

• Surface functionalisation of nanoparticles
• Stabilisation of colloids & nanocomposites
• Layer-by-layer assembly coatings

2. Chemical & Polymer Synthesis

• Crosslinking agent for epoxy, acrylic, and polyurethane systems
• Catalyst and ligand modification
• Polymer modification and branching

3. Biotechnology

• DNA/RNA binding polymer (for research transfection systems)
• Immobilisation of biomolecules
• Component of hydrogels and biomaterials

4. Environmental & Industrial Applications

• Heavy metal chelation
• Water and wastewater treatment
• Coagulation/flocculation
• Resin and membrane surface modification

Ordering Information

Thermo Scientific™ Polyethyleneimine (PEI), M.W. 1,800 ≥99%, branched, is a highly versatile, reactive, and high-purity cationic polymer suitable for nanomaterials development, polymer modification, biotechnology, catalysis, and water treatment. Its moderate molecular weight provides excellent workability while delivering strong binding, chelation, and crosslinking performance—making it ideal for research laboratories and industrial applications alike.