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Astier S, Johnson EC, Norvilaite O, Varlas S, Brotherton EE, Sanderson G, Leggett GJ, Armes SP. Controlling Adsorption of Diblock Copolymer Nanoparticles onto an Aldehyde-Functionalized Hydrophilic Polymer Brush via pH Modulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 38320303 PMCID: PMC10883040 DOI: 10.1021/acs.langmuir.3c03392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Sterically stabilized diblock copolymer nanoparticles with a well-defined spherical morphology and tunable diameter were prepared by RAFT aqueous emulsion polymerization of benzyl methacrylate at 70 °C. The steric stabilizer precursor used for these syntheses contained pendent cis-diol groups, which means that such nanoparticles can react with a suitable aldehyde-functional surface via acetal bond formation. This principle is examined herein by growing an aldehyde-functionalized polymer brush from a planar silicon wafer and studying the extent of nanoparticle adsorption onto this model substrate from aqueous solution at 25 °C using a quartz crystal microbalance (QCM). The adsorbed amount, Γ, depends on both the nanoparticle diameter and the solution pH, with minimal adsorption observed at pH 7 or 10 and substantial adsorption achieved at pH 4. Variable-temperature QCM studies provide strong evidence for chemical adsorption, while scanning electron microscopy images recorded for the nanoparticle-coated brush surface after drying indicate mean surface coverages of up to 62%. This fundamental study extends our understanding of the chemical adsorption of nanoparticles on soft substrates.
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Affiliation(s)
- Samuel Astier
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Edwin C Johnson
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Oleta Norvilaite
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Spyridon Varlas
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Emma E Brotherton
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - George Sanderson
- GEO Specialty Chemicals, Hythe, Southampton, Hampshire SO45 3ZG, U.K
| | - Graham J Leggett
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Steven P Armes
- Department of Chemistry, The University of Sheffield, Dainton Building, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
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2
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Chan DH, Wills JL, Tandy JD, Burchell MJ, Wozniakiewicz PJ, Alesbrook LS, Armes SP. Synthesis of Autofluorescent Phenanthrene Microparticles via Emulsification: A Useful Synthetic Mimic for Polycyclic Aromatic Hydrocarbon-Based Cosmic Dust. ACS APPLIED MATERIALS & INTERFACES 2023; 15:54039-54049. [PMID: 37944021 PMCID: PMC10685351 DOI: 10.1021/acsami.3c08585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023]
Abstract
Phenanthrene is the simplest example of a polycyclic aromatic hydrocarbon (PAH). Herein, we exploit its relatively low melting point (101 °C) to prepare microparticles from molten phenanthrene droplets by conducting high-shear homogenization in a 3:1 water/ethylene glycol mixture at 105 °C using poly(N-vinylpyrrolidone) as a non-ionic polymeric emulsifier. Scanning electron microscopy studies confirm that this protocol produces polydisperse phenanthrene microparticles with a spherical morphology: laser diffraction studies indicate a volume-average diameter of 25 ± 21 μm. Such projectiles are fired into an aluminum foil target at 1.87 km s-1 using a two-stage light gas gun. Interestingly, the autofluorescence exhibited by phenanthrene aids analysis of the resulting impact craters. More specifically, it enables assessment of the spatial distribution of any surviving phenanthrene in the vicinity of each crater. Furthermore, these phenanthrene microparticles can be coated with an ultrathin overlayer of polypyrrole, which reduces their autofluorescence. In principle, such core-shell microparticles should be useful for assessing the extent of thermal ablation that is likely to occur when they are fired into aerogel targets. Accordingly, polypyrrole-coated microparticles were fired into an aerogel target at 2.07 km s-1. Intact microparticles were identified at the end of carrot tracks and their relatively weak autofluorescence suggests that thermal ablation during aerogel capture did not completely remove the polypyrrole overlayer. Thus, these new core-shell microparticles appear to be useful model projectiles for assessing the extent of thermal processing that can occur in such experiments, which have implications for the capture of intact PAH-based dust grains originating from cometary tails or from plumes emanating from icy satellites (e.g., Enceladus) in future space missions.
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Affiliation(s)
- Derek
H. H. Chan
- Dainton
Building, Department of Chemistry, University
of Sheffield, Brook Hill, Sheffield, South
Yorkshire S3 7HF, U.K.
| | - Jessica L. Wills
- School
of Physics and Astronomy, University of
Kent, Canterbury, Kent CT2 7NH, U.K.
| | - Jon D. Tandy
- School
of Chemistry and Forensic Science, University
of Kent, Canterbury, Kent CT2 7NZ, U.K.
| | - Mark J. Burchell
- School
of Physics and Astronomy, University of
Kent, Canterbury, Kent CT2 7NH, U.K.
| | | | - Luke S. Alesbrook
- School
of Physics and Astronomy, University of
Kent, Canterbury, Kent CT2 7NH, U.K.
| | - Steven P. Armes
- Dainton
Building, Department of Chemistry, University
of Sheffield, Brook Hill, Sheffield, South
Yorkshire S3 7HF, U.K.
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3
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Farmer MAH, Musa OM, Armes SP. Efficient Synthesis of Hydrolytically Degradable Block Copolymer Nanoparticles via Reverse Sequence Polymerization-Induced Self-Assembly in Aqueous Media. Angew Chem Int Ed Engl 2023; 62:e202309526. [PMID: 37522648 PMCID: PMC10952355 DOI: 10.1002/anie.202309526] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/21/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Hydrolytically degradable block copolymer nanoparticles are prepared via reverse sequence polymerization-induced self-assembly (PISA) in aqueous media. This efficient protocol involves the reversible addition-fragmentation chain transfer (RAFT) polymerization of N,N'-dimethylacrylamide (DMAC) using a monofunctional or bifunctional trithiocarbonate-capped poly(ϵ-caprolactone) (PCL) precursor. DMAC monomer is employed as a co-solvent to solubilize the hydrophobic PCL chains. At an intermediate DMAC conversion of 20-60 %, the reaction mixture is diluted with water to 10-25 % w/w solids. The growing amphiphilic block copolymer chains undergo nucleation to form sterically-stabilized PCL-core nanoparticles with PDMAC coronas. 1 H NMR studies confirm more than 99 % DMAC conversion while gel permeation chromatography (GPC) studies indicate well-controlled RAFT polymerizations (Mw /Mn ≤1.30). Transmission electron microscopy (TEM) and dynamic light scattering (DLS) indicate spheres of 20-120 nm diameter. As expected, hydrolytic degradation occurs within days at 37 °C in either acidic or alkaline solution. Degradation is also observed in phosphate-buffered saline (PBS) (pH 7.4) at 37 °C. However, no degradation is detected over a three-month period when these nanoparticles are stored at 20 °C in deionized water (pH 6.7). Finally, PDMAC30 -PCL16 -PDMAC30 nanoparticles are briefly evaluated as a dispersant for an agrochemical formulation based on a broad-spectrum fungicide (azoxystrobin).
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Affiliation(s)
- Matthew A. H. Farmer
- Department of ChemistryThe University of SheffieldBrook HillS3 7HFSheffieldSouth YorkshireUK
| | - Osama M. Musa
- Ashland Specialty Ingredients1005 US 202/20608807BridgewaterNJUSA
| | - Steven P. Armes
- Department of ChemistryThe University of SheffieldBrook HillS3 7HFSheffieldSouth YorkshireUK
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4
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Neal TJ, Penfold NJW, Armes SP. Reverse Sequence Polymerization‐Induced Self‐Assembly in Aqueous Media. Angew Chem Int Ed Engl 2022; 61:e202207376. [PMID: 35678548 PMCID: PMC9541501 DOI: 10.1002/anie.202207376] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 11/06/2022]
Abstract
We report a new aqueous polymerization‐induced self‐assembly (PISA) formulation that enables the hydrophobic block to be prepared first when targeting diblock copolymer nano‐objects. This counter‐intuitive reverse sequence approach uses an ionic reversible addition–fragmentation chain transfer (RAFT) agent for the RAFT aqueous dispersion polymerization of 2‐hydroxypropyl methacrylate (HPMA) to produce charge‐stabilized latex particles. Chain extension using a water‐soluble methacrylic, acrylic or acrylamide comonomer then produces sterically stabilized diblock copolymer nanoparticles in an aqueous one‐pot formulation. In each case, the monomer diffuses into the PHPMA particles, which act as the locus for the polymerization. A remarkable change in morphology occurs as the ≈600 nm latex is converted into much smaller sterically stabilized diblock copolymer nanoparticles, which exhibit thermoresponsive behavior. Such reverse sequence PISA formulations enable the efficient synthesis of new functional diblock copolymer nanoparticles.
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Affiliation(s)
- Thomas J. Neal
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
| | - Nicholas J. W. Penfold
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
| | - Steven P. Armes
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
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Chi Y, Ye Z, Su X, Li Z, Ren X. Fabrication and applications of a microencapsulated prothioconazole based on β-cyclodextrin. APPLIED NANOSCIENCE 2022. [DOI: 10.1007/s13204-022-02577-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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6
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Neal TJ, Penfold NJW, Armes SP. Reverse Sequence Polymerization‐Induced Self‐Assembly in Aqueous Media. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Thomas J. Neal
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
| | - Nicholas J. W. Penfold
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
| | - Steven P. Armes
- Department or Chemistry The University of Sheffield Brook Hill, Sheffield, South Yorkshire S3 7HF UK
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Ohtake T, Ito H, Toyoda N. Amphiphilic Polymers for Color Dispersion: Toward Stable and Low-Viscosity Inkjet Ink. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7618-7627. [PMID: 35679371 DOI: 10.1021/acs.langmuir.2c01010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Amphiphilic random and block copolymers were synthesized as potential inkjet inks. This study evaluated the potential of these polymers for color dispersion by examining the following factors: surface tension, zeta potential, viscosity, and particle size. Acrylic acid and (ethoxyethoxy)ethyl acrylate were used as the hydrophilic molecular units. Styrene, butyl acrylate, and phenoxyethyl acrylate were used as hydrophobic units. Color dispersions were prepared by using organic dye and these amphiphilic polymers. The color dispersions containing random copolymers exhibited low viscosity, which is preferable for jetting, but the dye particles tended to sediment after the thermal aging test. In contrast, those containing block copolymers showed high viscosity, which was unsuitable for jetting. However, they retained their initial dispersion state after the aging test. The advantages and disadvantages of each monomer arrangement (random or block) were demonstrated, providing a future outlook on the molecular design of polymer dispersants for color dispersions.
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Affiliation(s)
- Toshihiro Ohtake
- Environment and Materials Development Department, Corporate Research and Development Division, Seiko Epson Corporation, 80 Harashinden, Hirooka, Shiojiri, Nagano 399-0785, Japan
| | - Hiroshi Ito
- Environment and Materials Development Department, Corporate Research and Development Division, Seiko Epson Corporation, 80 Harashinden, Hirooka, Shiojiri, Nagano 399-0785, Japan
| | - Naoyuki Toyoda
- Environment and Materials Development Department, Corporate Research and Development Division, Seiko Epson Corporation, 80 Harashinden, Hirooka, Shiojiri, Nagano 399-0785, Japan
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