A method is presented for the synthesis of self-assembling nanoparticle surfactants in nonpolar organic solvents. The method relies on the control of long-range steric repulsion imparted by grafted polystyrene and short-range attraction from short-chain thiol molecules with an alcohol or carboxylic functionality. Similar to water-based nanoparticle surfactants, these oil-dispersed materials are found to cluster in dispersion and also to stabilize oil-water interfaces to form water-in-oil emulsions. The clustering process is characterized with dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), UV-vis spectroscopy, and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) is used to quantify the surface concentration of grafted polymer, which is found to be a parameter of critical importance for the formation of stable clusters. The clustering kinetics and dispersion stability are both affected by the polymer molecular weight, surface concentration, and chemical structure of the thiol molecules that induce particle attraction. Nanometer-sized water-in-oil emulsions are formed by sonication in the presence of nanoparticle surfactants. A large broadening of the optical absorption spectrum in the NIR region is observed because of changes in the collective surface plasmon resonance of the gold particle shell.
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http://dx.doi.org/10.1021/la504520p | DOI Listing |
J Phys Chem C Nanomater Interfaces
January 2025
Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Ave., San Francisco, California 94132, United States.
Water electrolysis is a green method of storing electrical energy in the chemical bonds of high-energy hydrogen gas (H). However, the anodic oxygen evolution reaction (OER) requires a significant kinetic overpotential, limiting the electrolysis rate. Recently, plasmonic gold nanoparticles (Au NPs) have been introduced to improve charge transfer at the interface between the OER electrocatalysts and the electrolyte under light illumination.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
A novel PLGA-inspired NP polymerization technique is presented, which allows the formation of NPs via the cross-linking of precisely sequenced short oligolactoglycolic acid dimethacrylates (OLGADMAs). Following the synthesis of a range of OLGADMAs, a library of NPs via this rapid and surfactant-free nanopolymerization method is successfully generated, which permits the simultaneous NP formation and encapsulation of drugs such as dexamethasone. The results indicate that NPs produced through this nanopolymerization technique with precisely controlled sequences exhibit heightened stability compared to conventionally sequenced and non-sequence controlled PLGA, as evidenced by minimal pH changes over five weeks.
View Article and Find Full Text PDFJ Nanobiotechnology
January 2025
Department of Orthopedics, Huashan Hospital, Fudan University, No. 12, Middle Wulumuqi Road, Jing'an District, Shanghai, 200040, China.
Background: Spinal cord injury (SCI) treatment remains a formidable challenge, as current therapeutic approaches provide only marginal relief and fail to reverse the underlying tissue damage. This study aims to develop a novel composite material combining enzymatic nanoparticles and nerve growth factor (NGF) to modulate the immune microenvironment and enhance SCI repair.
Methods: CeMn nanoparticles (NP) and CeMn NP-polyethylene glycol (PEG) nanozymes were synthesized via sol-gel reaction and DSPE-mPEG modification.
Sci Rep
January 2025
Department of Mechanical and Manufacturing Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India.
Vegetable oil-based lubricants, modified through transesterification and epoxidation, present a sustainable alternative to mineral lubricants for transport and industrial use. This study evaluates epoxidized jatropha oil (EJA) enhanced with multi-walled carbon nanotubes (MWCNT) as a bio-lubricant for compression ignition engines. MWCNT, dispersed in EJA using an ultrasonic probe sonicator with Triton X-100 as a surfactant, was tested at nanoparticle concentrations from 0.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Lab of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University 800 Dongchuan Road, Shanghai, P. R. China.
Reactive oxygen species with evoked immunotherapy holds tremendous promise for cancer treatment but has limitations due to its dependence on exogenous excitation and/or endogenous HO and O. Here we report a versatile oxidizing pentavalent bismuth(V) nanoplatform (NaBiO-PEG) can generate reactive oxygen species in an excitation-free and HO- and O-independent manner. Upon exposure to the tumor microenvironment, NaBiO-PEG undergoes continuous H-accelerated hydrolysis with •OH and O generation through electron transfer-mediated Bi-to-Bi conversion and lattice oxygen transformation.
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