Engineering topics

Cui, Shuang

Publications and source records attributed to Cui, Shuang.

6 records

DOE OSTI2024

Thermal diode and thermal switch for bi-directional heat transfer in building envelopes

The present disclosure relates to a directional heat transfer using thermal control devices, including a dual phase change thermal diode and an active contact-based thermal switch. The thermal diode includes a positive temperature coefficient switching material and a negative temperature coefficient switching material arranged in series. The thermal switch includes two thermally conducting surfaces which may be moved to contact (i.e., having a distance between them of substantially zero) creating minimal thermal contact resistance. Both thermal control devices may be used to control heat flow into and/or out of a building.

Kishore, Ravi Anant↗

DOE OSTI2023

Super-adsorbing porous thermo-responsive desiccants

Thermo-responsive hydrogel composite (TRHC) desiccants having high adsorption capacities, fast adsorption/desorption rates, and low regeneration temperatures (Treg) compared to traditional desiccants. TRHC desiccants may be synthesized by freeze drying. The porous structures resulting from freeze drying copolymers of thermo-responsive polymers and/or hygroscopic agents may be combined with hygroscopic inorganic salts, resulting in TRHC desiccants having superior performance properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2023

Engineered Polymer Architectures for Thermo–Responsive Desiccants in Dehumidification Applications

Humidity control is relevant to many processes in buildings and manufacturing and is responsible for over 600 million tons of CO 2 annually. As such, desiccants that can efficiently remove moisture from air can greatly reduce emissions. A new class of desiccant materials, thermo–responsive desiccants, has been of increased interest in the literature. These materials are generally based on thermo–responsive polymers and exhibit a temperature–dependent isotherm, an attribute that is small in traditional desiccants. In this work, seven key parameters needed to create an effective thermo–responsive polymer desiccant are identified using a combination of modeling and experimental data. Further, it is found that more thermo–responsiveness is not necessarily better for energy efficiency, and that an optimal, “medium” value is desired. Additionally, polymer composition and architecture play key roles in adjusting the seven key parameters. Finally, based on findings from both modeling and experimental work, guidelines on synthesizing future thermo–responsive polymer desiccants are presented.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2023

Switchable photovoltaic devices

The present disclosure relates to a composition that includes a scaffold having an internal space and a mixture positioned within the space, where the mixture includes a first phase having a metal halide perovskite and a second phase including at least one of a perovskite precursor and/or a switching molecule, the composition is capable of reversibly switching between a first state having at least one of a first transparency and/or a first color and a second state having at least one of a second transparency and/or a second color.

Wheeler, Lance Michael↗

DOE OSTI2023

Carbon Additive Manufacturing with a Near-Replica “Green-to-Brown” Transformation

Nanocomposites containing nanoscale materials offer exciting opportunities to encode nanoscale features into macroscale dimensions, which produces unprecedented impact in material design and application. However, conventional methods cannot process nanocomposites with a high particle loading, as well as nanocomposites with the ability to be tailored at multiple scales. A composite architected mesoscale process strategy that brings particle loading nanoscale materials combined with multiscale features including nanoscale manipulation, mesoscale architecture, and macroscale formation to create spatially programmed nanocomposites with high particle loading and multiscale tailorability is reported. The process features a low-shrinking (<10%) “green-to-brown” transformation, making a near-geometric replica of the 3D design to produce a “brown” part with full nanomaterials to allow further matrix infill. Here, this demonstration includes additively manufactured carbon nanocomposites containing carbon nanotubes (CNTs) and thermoset epoxy, leading to multiscale CNTs tailorability, performance improvement, and 3D complex geometry feasibility. The process can produce nanomaterial-assembled architectures with 3D geometry and multiscale features and can incorporate a wide range of matrix materials, such as polymers, metals, and ceramics, to fabricate nanocomposites for new device structures and applications.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Salt hydrate-based phase change thermal energy storage and encapsulation thereof

Among other things, the present disclosure relates to phase change material (PCM) composites composed of an PCM mixed with a nucleating agent contained within the pores of a graphite matrix and/or a hydrogel. The process to create these PCM composites includes coating the surface of graphite with a surfactant, compressing the graphite to form a matrix, then filling the graphite matrix with the PCM.

Odukomaiya, Adewale↗