About

Jian Qin is an Associate Professor in the Department of Chemical Engineering at Stanford University. His research focuses on developing a microscopic understanding of the structural and physical properties of soft matters through a combination of analytical theory, scaling argument, numerical computation, and molecular simulation. His work covers areas such as the self-assembly of multi-component polymeric systems, the molecular origin of entanglement and polymer melt rheology, coacervation of polyelectrolytes, Coulomb interactions in dielectrically heterogeneous electrolytes, and surface charge polarizations in particulate aggregates in the presence or absence of flow. He worked as a postdoctoral scholar with Juan de Pablo at the Institute for Molecular Engineering at the University of Chicago and with Scott Milner in the Department of Chemical Engineering at Pennsylvania State University. Jian Qin received his Ph.D. in Chemical Engineering and Materials Science from the University of Minnesota under the supervision of David Morse and Frank Bates.

Research topics

• Thermodynamics
• Organic chemistry
• Inorganic chemistry
• Physical chemistry
• Chemistry
• Chemical engineering
• Materials science
• Metallurgy

Selected publications

• Research on the Optimization of Digital Six Lane Traffic Protection Full Section Layout for Expressway Reconstruction and Expansion

  SAE technical papers on CD-ROM/SAE technical paper series · 2025-10-17

  article1st authorCorresponding

  <div class="section abstract"><div class="htmlview paragraph">To explore the comparison and optimization of cross sections for six lane traffic organization in the digital design conditions of expressway reconstruction and expansion, a systematic analysis was conducted on the selection and different combinations of cross section layout parameters for bidirectional six lane traffic protection schemes during the construction period based on the Guangzhou Shenzhen Expressway reconstruction and expansion project. A simulation model based on real traffic flow was constructed, and a recommended cross section layout scheme for six lane traffic protection schemes during expressway reconstruction and expansion construction based on traffic safety and traffic efficiency was proposed. The comprehensive ranking of cross section parameter importance was given. The results showed that in terms of comprehensive importance priority, the right lateral clearance width>right lane width>left lateral clearance width>middle lane width>left lane width can provide reference for the optimization of cross section layout for six lane traffic protection schemes in expressway reconstruction and expansion projects.</div></div>

  PublisherDOI

• Enhancing Volumetric Energy Density in Lithium–Sulfur Batteries through Highly Dense, Low Tortuosity Sulfur Electrodes

  Advanced Energy Materials · 2025-04-15 · 4 citations

  article

  Abstract Recent advancements in Lithium–sulfur (Li─S) batteries have significantly improved cell‐specific energy, while challenges persist in improving volumetric energy and cell cycle life. In this study, a design principle is elucidated to enhance sulfur utilization in high‐density and high‐sulfur‐content electrodes using a liquid‐templated shear‐rolling method. The findings indicate that a vascular‐like hierarchical electrode structure and compatible liquid electrolytes are critical for improving electrolyte permeability in dense electrodes, achieving high sulfur utilization (>1200 mAh g −1 ) under practical conditions (47% cathode porosity, S loading 4.5 mg cm −2 , S content 70%, E/S 4 mL g −1 ). Li─S pouch cells are demonstrated with an exceptionally high volumetric energy density (668 Wh L −1 ) and extended cycle life by integrating the optimized electrode structures and electrolytes. This study advances understanding and design of high volumetric energy Li─S cells. Additionally, the proposed templated shear‐rolling technique shows potential for application in the fabrication of other high‐energy electrodes.

  PublisherDOI

• A High-Efficiency Dual-Band Power Amplifier Based on Tri-Band Impedance Matching Circuit with Adjustable Transmission Zeros

  2025-05-19

  articleSenior author

  This paper proposes a high-efficiency dual-band power amplifier (PA) design for wireless communication systems. A dual-band(DB) third-harmonic control structure is employed to enhance efficiency, while a tri-band(TB) impedance matching network is utilized to achieve dual-band operation by intentionally mismatching the intermediate frequency as a stopband, thereby improving inter-band isolation. Adjustable transmission zero(TZ) are integrated to further extend bandwidth and enhance out-of-band suppression. Experimental results for the operating frequency bands of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.6-1.84 \text{GHz}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.45-2.64 \text{GHz}$</tex> demonstrate an average saturated output power of over 41 dBm and 39 dBm, with gains exceeding 11 dB and 9 dB in the two bands, respectively. The drain efficiency (DE) ranges from 62 to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$70.8 \%$</tex> and 62.6 to 78.5%. The stopband (2.05-2.2 GHz) exhibits a DE of less than 1% and a gain below -15 dB.

  PublisherDOI

• Parameterizing Conjugated Polymers as Ribbon-like Chains

  Macromolecules · 2025-10-29 · 1 citations

  articleSenior author
  PublisherDOI

• Sodium storage properties of Fe, Ni-bimetallic doped carbon-modified NaTi2(PO4)3

  International Journal of Minerals Metallurgy and Materials · 2025-09-01 · 2 citations

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  PublisherDOI

• Electrostatic correlation free energy for finite polymer chains

  Soft Matter · 2025-01-01 · 1 citations

  articleSenior author

  . Closed-form expressions for the free energy are provided for polyelectrolytes exhibiting either coil- or rod-like statistics, in the absence or presence of small ions. The consequence of the end effect is demonstrated by evaluating the phase diagram, surface tension, and molecular weight-driven partitioning.

  PublisherDOI

• Molecular Weight-Driven Partitioning of Polyelectrolytes During Complexation

  Macromolecules · 2025-06-05 · 2 citations

  articleSenior authorCorresponding

  Relatively little is known of how disperse polyions are partitioned between coacervate and supernatant phases. We investigate MW-driven partitioning by mixing like-charged polyions with distinct molecular weights (MWs) and a single oppositely charged polyion. Using multiple dye-labeled polyions, we show that high-MW polyions are enriched in the coacervate and depleted from the supernatant. The partition coefficients mainly depend on the polyion stoichiometry and MW ratio, and only weakly depend on the salinity. These observations are semiquantitatively modeled by considering competition between the translational entropy of polyions and electrostatic correlation free energy. As a dramatic demonstration of the consequences of MW-driven partitioning, we show that adding high-MW polyions depletes shorter polyions from preformed coacervate droplets. The resulting chain-exchange dynamics are visualized using confocal microscopy, enabling quantitative study of the coacervate droplet size distribution, exchange time scales, and diffusion coefficients.

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• Asymmetric ether solvents for high-rate lithium metal batteries

  Nature Energy · 2025-02-14 · 101 citations

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• Elucidating the Effects of LiF on Lithium Metal Anodes

  Nano Letters · 2025-09-29 · 20 citations

  articleCorresponding

  O. These findings shed light on the effects of LiF on Li metal anodes and the arrangement characteristic of LiF within the SEI. By integrating key discoveries regarding LiF, a projected working mechanism for LiF is illustrated. Overall, our study on LiF provides valuable insights that advance the understanding of the SEI and interphase nanostructures, contributing to the development of more reliable and practical Li metal batteries.

  PublisherDOI

• Novel Polymer Gel Lubricant Functionalized with a Phosphate Anion for Friction Reduction and Film Thickness Enhancement in Multiple Lubrication Conditions

  ACS Applied Materials & Interfaces · 2025-02-08 · 8 citations

  article

  In this study, a supramolecular polymer gelator functionalized with a phosphate anion, PMUS-P, has been successfully synthesized through radical polymerization, and its physicochemical, rheological properties and tribological performance were carefully evaluated as a gel lubricant formed through non-covalent self-assembly in 500SN base oil. The results showed that the gel has a dense network structure, providing excellent stability and mechanical strength. Additionally, the PMUS-P gel exhibits good shear-thinning behavior and excellent creep recovery, effectively avoiding the volatility of lubricants. Under a steel-steel contact, the PMUS-P gel showed excellent tribological performance in long-term wear tests and a high-load, high-frequency, or high-temperature condition. For instance, in long wear tests, the 15 wt % PMUS-P gel showed a 44.90% reduction in average coefficient of friction (COF) compared to 500SN base oil, along with an 88.05% decrease in wear. The lubrication mechanism study revealed that the chemical reactive film formed by friction played a key role in reducing friction and wear, preventing the friction pairs from direct contact. In terms of film-forming properties, the PMUS-P gel demonstrates superior lubrication performance in comparison to 500SN base oil, achieving higher film thickness. Given these advantages, the PMUS-P gel has significant potential for prolonging machinery service life and reducing operational energy consumption, promising to become a new high-performance lubricant.

  PublisherDOI

Recent grants

• CAREER: Dielectric Screening in Structured Polymer Electrolytes

  NSF · $500k · 2019–2023

Frequent coauthors

• Juan Pablo

  Argonne National Laboratory

  60 shared

• Mamoun Muhammed

  KTH Royal Institute of Technology

  44 shared

• Yi Cui

  Stanford University

  37 shared

• Zhenan Bao

  33 shared

• Xifei Li

  22 shared

• Andrea Fornara

  Swedish Institute

  21 shared

• Zhiao Yu

  20 shared

• Xian Kong

  South China University of Technology

  20 shared

Education

• Ph.D., Chemical Engineering

  Stanford University

  2005

• M.S., Chemical Engineering

  University of California, Berkeley

  2000

• B.S., Chemical Engineering

  University of Science and Technology of China

  1997