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[…] only improved paint performance but also optimizing aspects such as pigment efficiency (e.g., reduction of TiO2) and effective gloss management, while maintaining key characteristics such as abrasion performance and overall coating properties. At the same time, continued emphasis has been placed on reducing the environmental footprint through lower volatile organic content (VOC) in paint systems. In addition, increasing efforts have been directed to eventually replace typical petroleum-derived building blocks in coatings formulations with more sustainable, potentially renewable material alternatives. However, the transition to performance-advantaged renewable building blocks, which are accessible at an enabling cost position and are also based on fungible, readily available raw materials produced in a sustainable and scalable industrial process, remains challenging across material industries. This article discusses one specific example of renewable based additive technology to meet the stated industry performance needs and objectives. Engineered Polysaccharide Fundamental Material Properties Structurally, polysaccharides are highly diverse biopolymers composed of repeating glucose units linked via glycoside bonds. The range of polysaccharide structural characteristics, such as linkage isomers, the degree of polymerization, chain branching, and aggregation through strong intermolecular hydrogen bonding, allows these materials to be found in nature as structure-forming, essentially insoluble, highly aggregated materials (e.g., cellulose) or as water-soluble thickening materials with often various biological functions (e.g., starches, various gums). The interaction of individual polysaccharide polymer chains through hydrogen bonding to form associated supramolecular structures allows for deliberate material engineering from the nano to micron scale. For example, extensive works on various process options to access and control submicron-scale cellulose-based materials (i.e., micro-/nano-fibrillated cellulose, micro-/nano-cellulose) are reported.1,2 Enzymatic polymerization allows for a novel, controlled path towards engineering of nano- to micron-scale primary structures within aggregated, typically micron-sized polysaccharide materials. Efficient and scalable methods to apply a monomer-based (e.g., sucrose), controlled polymerization protocol using an enzyme catalyst to engineer polysaccharide materials is emerging for first commercial, large-scale applications. The specific family of biocatalysts is selected from the general class of glucosyltransferase (GTF) enzymes, and the polymers can be produced by reacting a solution of sucrose with this GTF enzyme. For the work described here, the alpha-1,3-glucan utilized has a typical degree of polymerization of 800 glucose repeat units with a polydispersity in the range of 1.7–2.0, as controlled by the polymerization process conditions (Figure 1). The alpha-1,3-glucan polymer generated in the enzymatic polymerization process is isolated as a water-insoluble, semicrystalline, highly structured material. Significant association through hydrogen bonding generates primary particles with a narrow particle size range (~10–30 nm), which further aggregate and agglomerate to form spherical particles in the range of approximately 500–5000 nanometers (Figure 2). The polysaccharide isolated from this biopolymerization process is a free-flowing white powder that is water insoluble but water dispersible. It is hydrophilic with an open microstructure that is colloidally stable and can be redispersed under shear to form a colloidal dispersion in water, which shows high viscosity and is shear thinning. Polysaccharides in general are hydrophilic materials and will show a significant extent of associated water at equilibrium; however, the solubility in water will depend on the linkage, the molecular weight, and the degree of intramolecular chain association through hydrogen bonding. For example, linear dextrose (alpha-1,6-glucan), a typically water-soluble starch (blend of alpha 1,4 and 1,6 glucans), usually swells and expands in water, while typically cellulose (beta-1,4 glucan) though hydrophilic, remains undissolved in water and requires strong aprotic or coordinating solvent systems to generate true solutions. The alpha-1,3-glucan utilized in this work is also water-insoluble, similar to cellulose. Figure 3 shows the shear viscosity of a 7 wt% colloidal dispersion of alpha-1,3-glucan in water. Black dots in the figure show the typical shear-thinning behavior of the material, while the shear stress of the sample is shown with red dots. At low shear rate, the shear stress shows a plateau, indicative of the yield stress required for the sample to flow. Figure 4 shows the viscosity of the colloidal dispersion increasing with solids loading. For concentrations > 10 wt% the system transitions from a flowing system to a soft solid. The transition […]