Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: Graphical illustrations and a practical application of the SU8 polymer before and after conjugation with m -phenylenediamine ( m -PD). The upper left panel represents the dimeric form of the SU8 polymer prior to the conjugation process with m -PD. The lower left panel shows the resulting structure post-conjugation, depicting the modifications imparted to the SU8 polymer by m -PD. The right panel showcases a possible optoelectronic application: a glass slide with the polymer deposited onto its surface, and a waveguide fabricated within the polymer using a laser.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques: Polymer, Conjugation Assay

Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: Optical properties of SU8 polymers with varying viscosities (SU8-2000.5, SU-8-3005, and SU8-3050) conjugated with m -PD molecules and the influence of different amounts of hydrochloric acid being added to the reaction medium. The first column represents SU-8-2000.5, the second – SU8-3005, and the third – SU8-3050. (a–c) Absorbance spectra at 330 nm to 700 nm illustrate the impact of polymer viscosity. (d–f) PLE spectra (normalized) of the 530 nm emission peak, measured between 330 nm and 500 nm, highlighting the excitation-dependent behavior of the conjugates with varying viscosities. (g–i) Normalized emission spectra of conjugated SU-8 polymers at 450 and 650 nm range with excitation at 420 nm.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques: Polymer, Viscosity

Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: (a) Full-range ATR Fourier-transform infrared (FTIR) spectra of the conjugation process between meta -phenylenediamine ( m -PD) and SU8, indicating the characteristic peaks corresponding to the functional groups involved. This spectrum provides an overview of the complex interactions that transpire during the conjugation process. (b) Detailed FTIR spectra in the 2800–3100 cm −1 region, highlighting the specific vibrations attributed to various functional groups. (c) FTIR spectra in the 1150–1800 cm −1 region, further delineating the presence of different functional group vibrations, including the potential formation of secondary amine and amide bonds. (d) FTIR spectra in the 1150–550 cm −1 region, emphasizing the broad range of potential functional group interactions. The distinct peaks in this region are instrumental in deducing the nature of the interactions. (e) Several structures among the proposed configurations, while other options are analyzed further and hypothesized as less probable, and (except for model 2) the others are in the first stage toward tertiary amination.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques: Fourier Transform Infrared Spectroscopy, Conjugation Assay, Functional Assay

Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: 1 H-NMR analysis of the SU8- m PD conjugate. (a) Provides a full view of the entire spectrum. Region-specific magnifications further elucidate the interactions: (b) emphasizing the 6.5–8 ppm range, which is dominated by aromatic proton resonances, indicative of the SU8 and m -PD aromatic structures. (c) The 2.25–4.5 ppm region, highlighting potential transitional groups and intermediates; and (d) focusing on the 0–2.25 ppm range, predominantly showcasing aliphatic proton environments.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques:

Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: (a–d) Probable molecular structures of the m -PD-SU8 composite. The structures visualize the possible conformations resulting from the interaction between m -PD molecules and SU8 polymers. Each structure is presented as (a), (b), (c) and (d), demonstrating different plausible formations with band gap energies suitable for green emission. These structures were visualized and rendered using the VESTA software. Alongside each molecular structure, the calculated band gaps are provided, accompanied by the respective highest occupied molecular orbital (HOMO, shown at the bottom) and the lowest unoccupied molecular orbital (LUMO, shown at the top) charge distributions.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques: Software

Journal: Nanoscale

Article Title: Thin-film conformal fluorescent SU8-phenylenediamine †

doi: 10.1039/d3nr02744a

Figure Lengend Snippet: Characterization of the SU8- m -PD conjugated thin films. (a) HRSEM image of the m -PD conjugated film in normal mode, showcasing the adherence and consistency of the film with an inset displaying an enlarged view of a marked area at higher magnification. (b) HRSEM image of a cross-section of the m -PD conjugated film on a substrate, captured in backscatter mode, illustrating the film's thickness and uniformity, with an inset providing a magnified perspective of a designated region. (c) High-resolution AFM image of a 5 × 5 μm area of the m -PD-SU8 film, demonstrating minimal surface roughness and high uniformity. (d) Confocal images in XY, XZ, and YZ planes of the m -PD film deposited on a glass substrate under 488 nm excitation, presenting the film's fluorescence profiles and spatial distribution.

Article Snippet: Photoresists SU8-2000.5, -3005, and -3050, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and the SU8 developer were purchased from Bachem (UK) Ltd, meta -phenylenediamine ( m -PD), ortho -phenylenediamine ( o -PD), para -phenylenediamine ( p -PD), and hydrochloric acid (HCl) were purchased from Merck Ltd and 18 MΩ water.

Techniques: Fluorescence