Tailoring Pigment Dispersants with Polyisobutylene Twin-Tail Structures for Electrowetting Display Application

Abstract

We have designed a class of highly hydrophobic dispersants for finely dispersing carbon black and organic pigment nanoparticles in apolar mediums. The synthesis involved the use of polyisobutylene-g-succinic anhydride (PIB-SA) and judiciously selected amines by amidation and imidation. The structures were characterized by infrared spectroscopy for anhydride functionalities in the starting materials and amide/imide linkages in the products. These polymeric forms of dispersants were structurally varied with respects to their PIB molecular weight, twin-tails, and linkages. Their relative performance for dispersing six different pigments in decane was evaluated against solution homogeneity, viscosity, stability, and particle size. The fine dispersion was achieved at particle sizes of ca. 100 nm, with the viscosity as low as 2-3 cP. The measurement of zeta potentials, which varied from -39.8 to -5.1 mV with pigment addition, revealed a strong surface-charge interaction between pigment and PIB dispersant molecules. Examination by TEM (transmission electronic microscope) showed the homogeneous dispersion of the primary structures of pigment particles at ca. 20 nm in diameter. The polymeric dispersants with different PIB tails and imide functionalities could be tailored for pigment stability in the oil phase, which is potentially suitable for the electrowetting devices.

Synthesis of reactive self‐adhesive branched polyurethane dispersant for textile pigment printing

“…Polymer dispersant has attracted extensive attention over the past few decades for its prominent dispersing property and stability, which helps to balance pigment aggregation forces, including electrostatic attraction, van der Waals forces, hydrogen bonding, and hydrophobic interaction 10,11 . It equips with numerous anchoring groups that enhance the adsorption between particles and dispersant to form durable adsorption layers on the pigment particles 12 . Furthermore, long hydrophilic chains in the dispersant structure are wrapped around the surface of the pigment particles to provide effective steric hindrance 13,14 .…”

Synthesis and a Photo-Stability Study of Organic Dyes for Electro-Fluidic Display

“…High optical density, good solubility in non-polar solvent, and good light stability are the main characteristics for the designation of soluble organic dyes. A series of efforts to develop efficient dyes for electro-fluidic display have been conducted in previous research, such as the designation of anthraquinone dyes [9,10], azo dyes [11][12][13][14][15], dipyrrole methane metal dyes [16], and pigment dispersion [17,18]. However, for many of the dyes that were disclosed in patents, few were subjected to detailed research on their synthesis and specific application properties, especially their photo-stability properties.…”

Micellization and Adsorption to Carbon Black of Polyisobutylene‐Based Ionic Liquids

“…Polyisobutylene (PIB) has found widespread use as an additive in lubricating oils for internal combustion engines, specifically as a dispersant, due to its advantageous properties including a low glass transition temperature ( T g ), chemical, oxidative, and thermal stability, and ease of chemical modification . PIB succinimide (PIBSI) is a commercially produced PIB‐based dispersant commonly used in lubricating oils to maintain solubility of polyaromatic hydrocarbons (PAHs) (i.e., soot), which are produced from incomplete combustion of fuel and are carried into the lubricating oil when exhaust gases pass the piston rings .…”