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Search Publications by: Yun Liu (Fed)

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Displaying 26 - 50 of 94

Alignment of Worm-like Micelles at Intermediate and High Shear Rates

February 1, 2020
Author(s)
Brisa Arenas-Gomez, Cristina Garza, Yun Liu, Rolando Castillo
Hypothesis. Rheology combined with Small Angle Neutron Scattering (Rheo-SANS) can determine the local structural order in Worm-like Micelle (WLM) solutions, when the shear rate increases beyond the ending of the gradient shear banding, where the micellar

Dynamic Equivalence between Soft Star Polymers and Hard Spheres

November 19, 2019
Author(s)
Zhe Wang, Antonio Faraone, Panchao Yin, Lionel Porcar, Yun Liu, Changwoo Do, Kunlun Hong, Wei-Ren Chen
We measure a series of star polymer dispersions to study the dynamics of soft colloidal liquids. We find that as the concentration increases, the slowing of the long-time self-diffusivity of the star polymer, normalized by the short-time self-diffusivity

Orientational Distribution Function of Aligned Elongated Molecules and Particulates Determined from Their Scattering Signature

October 15, 2019
Author(s)
Guan-Rong Huang, Yangyang Wang, Changwoo Do, Yuya Shinohara, Takeshi Egami, Lionel Porcar, Yun Liu, Wei-Ren Chen
We present a strategy for quantitatively evaluating the field-induced alignment of non-spherical particles using small angle scattering techniques. The orientational distribution function (ODF) is determined from the anisotropic scattering intensity via

Quantification of a PbCl x Shell on the Surface of PbS Nanocrystals

August 5, 2019
Author(s)
Samuel W. Winslow, Yun Liu, James W. Swan, William A. Tisdale
Differences between the properties of PbS nanocrystals prepared using a large excess of PbCl 2 and those prepared using other Pb sources have led to speculation that a thin PbCl x shell may be present on the surface of PbCl 2-derived PbS nanocrystals

Characterization of Colloidal Nanocrystal Surface Structure using Small Angle Neutron Scattering and Efficient Bayesian Parameter Estimation

June 28, 2019
Author(s)
Samuel W. Winslow, Wenbi Shcherbakov-Wu, Yun Liu, William A. Tisdale, James W. Swan
Complete structural characterization of colloidal nanocrystals is challenging due to rapid variation in the electronic, vibrational, and elemental properties across the nanocrystal surface. while electron microscopy and X-ray scattering techniques can

In Situ Characterization of the Microstructural Evolution of Biopharmaceutical Solid-State Formulations with Implications for Protein Stability

January 7, 2019
Author(s)
Stijn H.S. Koshari, Purnendu K. Nayak, Shalini Burra, Isidro E. Zarraga, Karthikan Rajagopal, Yun Liu, Norman J. Wagner, Abraham M. Lenhoff
Lyophilized and spray-dried biopharmaceutical formulations are used to provide long-term stability for storage and transport, but questions remain about the molecular structure in these solid formulations and how this structure may be responsible for

Neutron Scattering in the Biological Sciences: Progress and Prospects

December 1, 2018
Author(s)
Rana Ashkar, Hassina Z. Bilheux, Heliosa Bordallo, Robert Briber, David J. E. Callaway, Xiaolin Cheng, Xiang-Qiang Chu, Joseph E. Curtis, Mark Dadmun, Paul Fenimore, David Fushman, Frank Gabel, Kushol Gupta, Frederick Herberle, Frank Heinrich, Liang Hong, John Katsaras, Zvi Kelman, Eugenia Kharlampieva, Gerald R. Kneller, Andrey Kovalevsky, Susan T. Krueger, Paul Langan, Raquel Lieberman, Yun Liu, Mathias Losche, Edward Lyman, Yimin NMN Mao, John Marino, Carla Mattos, Flora Meilleur, Peter Moody, Jonathan D. Nickels, William B. O'Dell, Hugh O'Neill, Ursula Perez-Salas, Judith Peters, Loukas Petridis, Alexei P. Sokolov, Robert Sutherland, Norman Wagner, Michael NMN Weinrich, Kevin Weiss, Troy Wymore, Yang Zhang, Jeremy C. Smith
The scattering of neutrons can be used to provide information on the structure and dynamics of biological systems on multiple scales of length and time. Pursuant to an NSF-funded workshop in February 2018, we review recent developments in this field as

Analysis of Small Angle Neutron Scattering Spectra from Deformed Polymers with Spherical Harmonic Expansion Method and a Network Model

November 13, 2018
Author(s)
Zhi-Yuan Wang, Dejia Kong, Lincan Yang, Hongwei Ma, Fengmei Su, Kanae N. Ito, Yun Liu, Xuewu Wang, Zhe Wang
In this paper, we combine the recently proposed spherical harmonic expansion (SHE) method [Phys. Rev. X 2017, 7, 031003] with a modified network model to analyze the small-angle neutron scattering (SANS) spectra from deformed entangled polymers. Focusing

Structure, Rheology, and Microrheology of Wormlike Micelles made of PB-PEO Diblock Copolymers

September 21, 2018
Author(s)
Antonio Tavera-Vazquez, Brisa Arenas-Gomez, Cristina Garza, Yun Liu, Rolando Castillo
A diblock copolymer made of poly(but-2-ene-1,4-diyl)-block-poly(oxyethylene), with a degree of polymerization of the polybutadiene and polyethylene blocks of 37 and 57, respectively, self-assembles in water as worm-like micelles determined with small angle

Scaling Behavior of Anisotropy Relaxation in Deformed Polymers

September 11, 2018
Author(s)
Christopher N. Lam, Wen-Sheng Xu, Wei-Ren Chen, Zhe Wang, Christopher B. Stanley, Jan-Michael Y. Carrillo, David Uhrig, Weiyu Wang, Kunlun Hong, Yun Liu, Lionel Porcar, Changwoo Do, Gregory S. Smith, Bobby G. Sumpter, Yangyang Wang
Drawing an analogy to the paradigm of quasi-elastic neutron scattering, we present a general approach for quantitatively investigating the spatiotemporal dependence of structural anisotropy relaxation in deformed polymers by using small-angle neutron

What Causes the Anomalous Aggregation in Pluronic Aqueous Solutions?

May 28, 2018
Author(s)
Kuo-Chih Shih, Zhiqiang Shen, Ying Li, Martin Kroger, Shing-Yun Chang, Yun Liu, Mu-Ping Nieh, Hsi-Mei Lai
Pluronic (PL) block copolymers has been widely used as delivery carriers, molecular templates for porous media, process additive of affecting rheological behavior. Unlike most surfactant systems, where unimer transforms into micelle with increased

Adsorption of Polysorbate 20 and Proteins on Hydrophobic Polystyrene Surfaces Studied by Neutron Reflectometry

April 21, 2018
Author(s)
Zhenhuan NMN Zhang, Sara V. Orski, Ann Marie Woys, Guangcui Yuan, Isidro E. Zarraga, Norman J. Wagner, Yun Liu
Understanding adsorption of protein and surfactant to hydrophobic surfaces is key for storage stability and delivery of pharmaceutical liquid formulations, because many commonly-used devices, such as drug containers and syringes, have product-containing

Simultaneous Neutron and X-Ray Imaging of 3D Structure of Organic Matter and Fracture in Shales

April 1, 2018
Author(s)
Wei-Shan NMN Chiang, Jacob M LaManna, Daniel S. Hussey, David L. Jacobson, Yun Liu, Jilin Zhang, Daniel T. Georgi, Jordan R. Kone, Jin-hong Chen
Hydrocarbon production from shales using horizontal drilling and hydraulic fracturing has been the key development in the US energy industry in the past decade and has now become more important globally. Nevertheless, many fundamental problems related to

A Non-Invasive Method to Directly Quantify Surface Heterogeneity of Porous Materials

February 22, 2018
Author(s)
Wei-Shan NMN Chiang, Daniel Georgi, Taner Yildirim, Jin-hong Chen, Yun Liu
Many porous materials have widely differing pore surface properties because the matrix materials forming the pores are heterogeneous at microscopic levels resulting in different adsorption/desorption behaviors and storage capacity of guest molecules in

Quasi-Two-dimensional Phase Transition of Methane Adsorbed in Cylindrical Silica Mesopores

November 29, 2017
Author(s)
Daniel W. Siderius, William P. Krekelberg, Wei-Shan NMN Chiang, Vincent K. Shen, Yun Liu
Using Monte Carlo and molecular dynamics simulations, we examine the adsorption of methane in cylindrical silica mesopores in an effort to understand a possible phase transition of adsorbed methane in MCM-41 and SBA-15 silica that was previously identified

Unraveling the Single-Nanometer Thickness of Shells of Vesicle-Templated Polymer Nanocapsules

August 3, 2017
Author(s)
Andrew G.. Richter, Sergey A. Dergunov, Mariya D. Kim, Sergey N. Shmakov, Sai Venkatesh Pingali, Volker S. Urban, Yun Liu, Eugene Pinkhassik
The recent emergence of vesicle-templated nanocapsules as a viable platform for diverse applications has heightened the need for detailed structural characterization of nanocapsule shells and for better understanding of surfactant-mediated directed