Colloid science has classically concerned itself with the investigation of properties of dispersed phases in a bulk medium. This has led to the development of a rich amount of chemistry, physics, and engineering that have facilitated the evolution and maturation of this field. One of the many developments made over the last 30 years is the introduction of colloidal particles that are heterogenous in both chemistry and shape. These heterogeneities can introduce behaviors that are not achievable in homogeneous systems and that are specific to the type and class of nonuniformity. This has led to the development of numerous technologies, two of which are Janus micromotors and solid surfactants. In this dissertation, we will develop new methods to synthesize and characterize these two heterogeneous polymer particle systems. In Chapter 1, we give an overview of the field of heterogeneous particles and techniques one can use to synthesize them. We then discuss the current state of the field for both solid surfactants and Janus micromotors. In Chapter 2 we develop dynamic light scattering as a characterization method to study the bulk three-dimensional active motion of Janus micromotors. From this work we find that dynamic light scattering can successfully characterize the non-steady state bulk active motion of Janus micromotor systems. This work positions dynamic light scattering to become an advanced characterization technique for Janus micromotor systems. In Chapter 3, we study the assembly mechanism of Janus particle solid surfactants at immiscible interfaces using dynamic pendant drop tensiometry. We find that by tuning the properties of the Janus particle that one can simultaneously both the binding energy but also the kinetics of assembly. In Chapter 4, we develop a new dimensionless number termed the active Bond number which can be used to analyze the deformation of immiscible interfaces by active matter and self-propelled colloids. We find that the active bond number is highly successful at predicting deformations for multiple experimental systems and can be broadly useful. We then conclude the dissertation with a summary of work and a future perspective on the fields of heterogeneous particles.