Significance: Liquid crystal (LC) research is rapidly expanding to include studies of curved and topologically nontrivial structures. Here, we explore the role of the bulk LC elasticity and interfacial free energy under weak thermal stimuli to achieve structural transformations in LC emulsions using two different surfactants. Our method is universal and could be used for any LC material or phase. A theoretical model for transforming LC emulsions into uniform fibers and vice versa is presented. We also show the self-shaping of smectic vesicle structures and monodispersed droplet formation at the nematic–smectic transition, utilizing the LC bulk elasticity. This work shows the potential to obtain the controllable shape of complex curved structures for a constant volume of different LCs and other soft materials.

Blends of polymers of different topologies, such as ring and supercoiled, naturally occur in biology and often exhibit emergent viscoelastic properties coveted in industry. However, due to their complexity, along with the difficulty of producing polymers of different topologies, the dynamics of topological polymer blends remains poorly understood. We address this void by using both passive and active microrheology to characterize the linear and nonlinear rheological properties of blends of relaxed circular and supercoiled DNA. We characterize the dynamics as we vary the concentration from below the overlap concentration c* to above (0.5c* to 2c*). Surprisingly, despite working at the dilute–semidilute crossover, entanglement dynamics, such as elastic plateaus and multiple relaxation modes, emerge. Finally, blends exhibit an unexpected sustained elastic response to nonlinear strains not previously observed even in well-entangled linear polymer solutions.

Entangled ring polymers, along with blends of ring and linear polymers, continue to be a topic of great interest and debate due to the conflicting experimental results in the literature as well as the difficulty of producing entangled synthetic rings devoid of linear contaminants. Here, we create blended solutions of entangled ring and linear DNA with varying mass fractions of linear DNA ${\varphi }_{\mathrm{L}}$. We use optical tweezers microrheology to measure the linear and nonlinear viscoelastic response of these blends. Our measurements reveal a strong nonmonotonic dependence of linear viscoelastic properties on ${\varphi }_{\mathrm{L}}$, with a pronounced maximum when the mass fraction of rings and linear chains are comparable, suggestive of pervasive threading of rings by linear chains. We observe a similar nonmonotonicity in the nonlinear regime. However, a comparatively higher fraction of linear chains (${\varphi }_{\mathrm{L}}\approx 0.5–0.7$) is required for a substantial increase in resisitive force and slowing of relaxation dynamics to emerge. This nonlinear response also appears to be rate dependent, which we argue arises from force-induced dethreading of rings at high strain rates. Our results fill a long-standing gap in knowledge regarding the microrheology and nonlinear response of ring-linear polymer blends. Moreover, the uniquely strong mechanical response that ring-linear blends exhibit, along with the ability to finely tune these blends by varying the blend composition, provides intriguing materials design principles.