A5091072354- Combustion and flame dynamics
- Cyclone Separators and Fluid Dynamics
- Hydrogels: synthesis, properties, applications
- Rocket and propulsion systems research
- Computational Fluid Dynamics and Aerodynamics
- biodegradable polymer synthesis and properties
- Polymer composites and self-healing
- Electrospun Nanofibers in Biomedical Applications
- Aerodynamics and Acoustics in Jet Flows
- Polymer Surface Interaction Studies
- Advanced Combustion Engine Technologies
- Particle Dynamics in Fluid Flows
- Wind and Air Flow Studies
- Advanced Sensor and Energy Harvesting Materials
- Plant Surface Properties and Treatments
- Carbon dioxide utilization in catalysis
- Refrigeration and Air Conditioning Technologies
- Advanced Materials and Mechanics
- 3D Printing in Biomedical Research
- Advanced Sensor Technologies Research
- Heat Transfer and Boiling Studies
- Engineering Applied Research
- Radiative Heat Transfer Studies
- Energy and Environmental Systems
- Heat transfer and supercritical fluids
University of North Carolina at Chapel Hill
2020-2025
Jeonbuk National University
2014-2021
Injectable hydrogels are desired in many biomedical applications due to their minimally invasive deployment the body and ability introduce drugs. However, current injectables suffer from mechanical mismatch with tissue, fragility, water expulsion, high viscosity. To address these issues, we design brush-like macromolecules that concurrently provide softness, firmness, strength, fluidity, swellability. The synthesized linear-bottlebrush-linear (LBL) copolymers facilitate improved...
Upcycling plastic waste into reprocessable materials with performance-advantaged properties would contribute to the development of a circular plastics economy. Here, we modify branched polyolefins and postconsumer polyethylene through versatile C–H functionalization approach using thiosulfonates as privileged radical group transfer functionality. Cross-linking functionalized polytopic amines provided dynamically cross-linked polyolefin networks enabled by associative bond exchange...
Abstract Current materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage brush-like polymer architecture to design administer minimally injectable elastomers cure vivo leachable-free implants with matching surrounding tissue. This strategy allows tuning curing time from minutes hours, which...
Brush-like thermoplastic elastomers combine softness, firmness, strength, and damping on par with soft tissues, which is vital for biomedical device adhesive applications.
Mechanically diverse polymer gels are commonly integrated into biomedical devices, soft robots, and tissue engineering scaffolds to perform distinct yet coordinated functions in wet environments. Such multigel systems prone volume fluctuations shape distortions due differential swelling driven by osmotic solvent redistribution. Living evade these issues varying proximal stiffness at nearly equal water concentration. However, this feature is challenging replicate with synthetic gels: any...
Architecturally hindered crystallization of bottlebrush graft copolymers offers a reaction- and solvent-free pathway for creating injectable elastomers with tissue-mimetic softness. Currently, materials involve solvents chemical reactions, leading to uncontrolled swelling, leaching unreacted moieties, side reactions tissue. To address this issue, poly(ethylene glycol) (PEG) amorphous block crystallizable poly(lactic acid) (PLA) grafted chains (A-g-B) were synthesized, controlled length...
Building brain foundation models to capture the underpinning neural dynamics of human behavior requires large functional datasets for training, which current implantable Brain-Computer Interfaces (iBCIs) cannot achieve due instability rigid materials in brain. How can we realize high-density recordings with wide region access at single-neuron resolution, while maintaining long-term stability required? In this study, present a novel approach overcome these trade-offs, by introducting Fleuron,...
An investigation on characteristics of spray generated by a pressure-swirl atomizer with adjustable swirl chamber length was performed. Spray were studied within the range (0.12 < length/diameter 0.5) using water as working fluid. Droplet Sauter mean diameter and velocity components measured phase-Doppler particle analyzer device. The cone angle from image processing images captured set Nd-YAG lasers high-speed camera. It found that ratio significantly affects such droplet size distribution...
The inability to re-process thermosets hinders their utility and sustainability. An ideal material should combine closed-loop recycling upcycling capabilities. This trait is realized in polydimethylsiloxane bottlebrush networks using thermoreversible Diels-Alder cycloadditions enable both reversible disassembly into a polymer melt on-demand reconfiguration an elastomer of either lower or higher stiffness. crosslink density was tuned by loading the functionalized with controlled fraction...
Abstract A two-phase flow parametric study on an air induction nozzle with water and as the working fluids is presented. Liquid was supplied at pre-orifice various inlet pressures ranging from 3 to 6 bar. The interaction between molecular level orifice exit leads formation of a strong shear layer that intensified increase in pressure. Thus, it vital regulate ratio intake liquid so generated micro bubbles fit design criteria. CFD analysis conducted using commercial software STAR CCM+ Siemens...
Abstract Hydrogels are explored for applications in agriculture, water purification, and biomedicine, leveraging softness, elasticity, high uptake. However, hydrogels notoriously brittle, especially at content. This shortcoming puts the improvement of hydrogel mechanics forefront current research. Yet modern strategies enhancing gel resilience come expense softness swelling. problem is addressed using bottlebrush networks with disentangled strands hidden length reservoirs, which...
This paper reports the particle image velocimetry (PIV) measurement of swirling flow in a confined rectangular-shaped model combustion chamber. Water is used as working fluid, and average profiles axial, radial, magnitudes velocity are given. Flow behavior investigated rebound angle term defined to investigate direct effects noncircular chamber shape. near walls discussed detail, other important features such appearance corner central toroidal recirculation zones. Additionally, experimental...
An experimental study is conducted to understand the mean and instantaneous behavior of swirling flow issued from a triple swirler influenced by single critical geometrical parameter, termed as passage length. The investigated parameter defines interaction point inner axial swirlers with outer radial swirler, which consequently primary air–fuel mixture characteristics resultant combustion state. Experiments were performed under cold conditions, planar particle image velocimetry was employed...
Polymer networks with brush-like (comb or bottlebrush) strands can have mechanical properties similar to biological tissues and swell larger volumes than their linear chain counterparts. We use a combination of the Flory–Rehner approach, scaling analysis, molecular dynamics simulations, experimental data for poly(n-butyl acrylate) (PBA) swollen in toluene elucidate effect brush strand architecture on equilibrium swelling ratio, Qeq, modulus gel, Ggel(Qeq), its relationship nonlinear dry...
The design of axial or radial swirlers typically governs a number geometrical parameters that are determined by the desired flow field. In meantime, unknown increases with concentrically mounted swirlers. available literature is nonetheless limited, and designers obligated to increase initial assumptions. this article, three kinds triple employed simulations performed determine effect each parameter on swirler performance. Based correlation provided, over-lengthening vane length could result...
Twin annular premixed swirler known as TAPS by GE has provided an effective solution to generate low NOx combustion implementing both diffusion and flames. The fuel injector is less susceptible instabilities owing its central flame eco-friendly due radial swirler. To this extent, 2D PIV experiment was conducted on three newly designed triple swirlers measure their corresponding velocity fields. were in a way that the inner intermediate are axial type, counter-rotating remained unchanged with...
In this paper, the temporal and time-averaged behaviors of internal external flow fields pressure swirl nozzle are investigated through a three-dimensional, two-phase flow, large-eddy simulation. The volume-of-fluid method is used to simulate air liquid regions using commercial package STAR-CCM+. constructed polyhedral grids refined locally, their quality assessed M-criterion slope fast-Fourier-transformed time-resolved probes. For detailed analysis, defined, data points extracted. MATLAB...
The effect of fuel temperature on the spray characteristics Jet A-1 aviation at various injection pressures discharged from a pressure swirl atomizer was studied. A two-dimensional phase Doppler anemometry system employed to measure droplet size, and laser sheet imaging used for taking high-quality images. properties fuel, especially viscosity, showed large variation according temperature. optical measurement results that atomization vary significantly depending temperature, particularly in...