We also compare our experimental findings with the results of molecular dynamics simulations to interpret the main trends in our measurements. The osmotic compressibility of the bottlebrush solution determined from macroscopic osmotic pressure measurements is compared with that estimated from SANS. Then, the results of osmotic pressure measurements are presented to quantify binary and ternary interpolymer interaction strengths, where the osmotic data are analyzed in terms of the Flory–Huggins theory. DLS is used to quantify the effects of the polymer concentration and ionic environment on the dynamic response of bottlebrush polymer solutions. A comparison is made between the effects of mono- and divalent salts (sodium chloride and calcium chloride) on the SANS profiles. The influences of the polymer concentration and ion concentration are studied. We present SANS results for bottlebrush solutions. The experimental results were complemented by molecular dynamics simulations of a coarse-grained bead–spring model that includes an explicit solvent. Both the polymer and ion concentrations were varied over a broad concentration range. We report systematic measurements using complementary experimental techniques, small angle neutron scattering (SANS), dynamic light scattering (DLS), and osmotic pressure measurements to characterize the structure of these solutions at the nanoscale and larger dimensions. We aim to determine the effects of the ionic environment on the solution structure of bottlebrush sodium polyacrylates in which the length of both the main chain (polymer backbone) and the side chain was varied. Elucidating these basic physical properties is of fundamental importance to fully understand the importance of the bottlebrush architecture for designing advanced materials and understanding basic molecular physics underlying certain biological functions. The effect of ions is particularly important in the biological milieu where both mono- and divalent counter-ions are present. 11 For example, the effect of charges on the conformation of bottlebrush molecules is poorly understood. 9,10ĭespite the tremendous potential of bottlebrush polymers in both materials science and biology, the effects of the charged bottlebrush topology on the physicochemical behavior of their solutions have not yet been fully elucidated. Furthermore, the bottlebrush architecture has excellent lubrication properties, protecting the articulating bone surfaces against frictional damage. The aggrecan/hyaluronic acid complexes are enmeshed in an interpenetrating collagen matrix, and these molecules govern the load bearing properties of the cartilage. 7,8 In the presence of hyaluronic acid and link protein, a secondary bottlebrush architecture is formed in which aggrecan molecules are condensed on a hyaluronic acid chain. In the cartilage extracellular matrix (ECM), the major proteoglycan component is the bottlebrush-shaped aggrecan molecule. Typical examples are cartilage and viscoelastic mucin layers forming protective coatings in the lungs, orifices, and digestive tracts of animals. 2–6 In addition to applications, bottlebrush architectures are essential components of living systems. Bottlebrush polymers are used as drug delivery agents, surface coatings, modifiers of rheological properties, etc. Recently, this class of materials has attracted a great deal of attention for both fundamental studies and applications. For example, entanglement interactions have been found to be greatly diminished in neutral bottlebrush polymers, 1 enabling the fabrication of materials for many applications, where soft materials of high mechanical stability are required, e.g., soft contact lenses. These polymers differ strongly from their linear polymer counterparts not only in their architecture but also in their physical properties that are primarily controlled by the length of the main and side chains, the grafting density, and the steric repulsion of the side chains. Bottlebrush polymers are comprised of densely grafted chains tethered to a polymer backbone.