A hypothesis about (transient) colloidal stability as a controlling mechanism for particle formation in SBA-15 is presented. The hypothesis is based on results from both in situ and ex situ investigations, including cryogenic transmission electron microscopy (cryo-TEM), UV-vis spectroscopy, and dynamic light scattering (DLS). Cryo-TEM images show that particles grow via the formation of silica-Pluronic-water "flocs", which coalesce in a seemingly arbitrary manner. Despite this, the final material consists of well-defined particles with a small size distribution. We argue that the interface between the flocs and surrounding media is covered by Pluronic molecules, which provide steric stabilization. As the flocs grow, the coverage of polymers at the interface is increased until a stable size is reached, and that regulates the particle size. By targeting the characteristics of the Pluronic molecules, during the on-going synthesis, the hypothesis is tested. The results are consistent with the concept of (transient) colloidal stability.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3836357 | PMC |
| http://dx.doi.org/10.1021/la3013969 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Weakening Coulomb interactions in ionic liquid via hydrogen bonds enables ultrafast supercapacitors.
J Colloid Interface Sci
January 2025
Shanxi Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001 China; Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049 China. Electronic address:
The application of ionic liquid electrolytes in ultrafast supercapacitors to achieve wide electrochemical operating windows and high electrochemical stability is highly applauded. However, the strong Coulomb interaction between ions leads to the overscreening effect and slow establishment process of the electrical double layer (EDL), which deteriorates the rate performance of supercapacitors. Herein, inspired by Coulomb's law and EDL transient dynamics, we introduce competitive hydrogen bond interactions into typical ionic-liquid electrolytes to weaken the Coulomb interaction between ions.
View Article and Find Full Text PDFDynamical arrest for globular proteins with patchy attractions.
Soft Matter
January 2025
Division of Physical Chemistry, Department of Chemistry, Lund University, PO Box 124, SE-221 00 Lund, Sweden.
Attempts to use colloid science concepts to better understand the dynamic properties of concentrated or crowded protein solutions are challenging due to the fact that globular proteins generally have heterogeneous surfaces that result in anisotropic or patchy contributions to their interaction potential. This is particularly difficult when targeting non-equilibrium transitions such as glass and gel formation in concentrated protein solutions. Here we report a systematic study of the reduced zero shear viscosity of the globular protein -crystallin, an eye lens protein that plays a vital role in vision-related phenomena such as cataract formation or presbyopia, and compare the results to the existing structural and dynamic data.
View Article and Find Full Text PDFRegulable crack patterns for the fabrication of high-performance transparent EMI shielding windows.
iScience
January 2025
State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences (CAS), Xi'an, Shaanxi 710119, China.
Crack pattern-based metal grid film is an ideal candidate material for transparent electromagnetic interference shielding optical windows. However, achieving crack patterns with narrow grid spacing, small wire width, and high connectivity remains challenging. Herein, an aqueous acrylic colloidal dispersion was developed as a crack precursor for preparing crack patterns.
View Article and Find Full Text PDFLinking structural and rheological memory in disordered soft materials.
Soft Matter
January 2025
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA.
Linking the macroscopic flow properties and nanoscopic structure is a fundamental challenge to understanding, predicting, and designing disordered soft materials. Under small stresses, these materials are soft solids, while larger loads can lead to yielding and the acquisition of plastic strain, which adds complexity to the task. In this work, we connect the transient structure and rheological memory of a colloidal gel under cyclic shearing across a range of amplitudes a generalized memory function using rheo-X-ray photon correlation spectroscopy (rheo-XPCS).
View Article and Find Full Text PDFMicroscale Electrical Resistivity Measurements to Investigate Particle Distribution.
Langmuir
January 2025
Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
The functional performance of a particulate thin film depends greatly on the particle distribution that forms during drying. In situ methods for monitoring the impact of different processing parameters on the distribution of particles currently require expensive and specialized equipment. This work addresses this gap by miniaturizing a geophysical prospecting method to thin-film applications.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!