The development of infrared (IR) plastic optics for infrared thermal imaging, particularly, in the long-wave IR (LWIR) spectrum (7-14 mu m) is an area of growing technological interest due to the potential advantages associated with plastic optics (e.g., moldability and low cost). The development of a new class of optical polymers, chalcogenide-based inorganic/organic hybrid polymers (CHIPs) derived from the inverse vulcanization of elemental sulfur, has enabled significant improvements in IR transparency due to reduction of IR absorbing organic comonomer units. The vast majority of effort has focused on new chalcogenide hybrid polymer synthesis and optical property improvements (e.g., refractive index, Abbe number, and LWIR transmission); however, fabrication and IR imaging methodology to prepare optical components has not been demonstrated, which remains critical to develop viable IR plastic optics. A new methodology is reported to fabricate optical components and evaluate LWIR imaging performance of this emerging class of optical polymers. New diffractive flat optics with a Fresnel lens design for these materials have been developed, along with a basic LWIR imaging system to evaluate CHIPs for LWIR imaging. This system-based approach enables correspondence of copolymer structure-property correlations with LWIR imaging performance, along with demonstration of room temperature LWIR imaging. The fabrication of Fresnel lenses with chalcogenide hybrid inorganic/organic polymers made by the inverse vulcanization of elemental sulfur is demonstrated along with the development of a basic long-wave infrared (LWIR) imaging system to enable structure-property-imaging studies of new LWIR transmissive polymeric materials. Successful LWIR imaging with both supported thin film and free-form plastic optics has been demonstrated as well as LWIR imaging under ambient conditions.image
In this study, the first fabrication of phase-shifted Bragg gratings utilizing chalcogenide hybrid inorganic/organic polymers (CHIPs) is presented based on poly(sulfur-random-(1,3-isopropenylbenzene) to measure the thermo-optic coefficient (TOC) of this new class of optical polymers. The unique properties of CHIPs, such as high index contrast and low optical losses, are leveraged to fabricate Bragg gratings that enable precise determination of the TOC and glass transition temperature (Tg) of these polymers. The optical measurement introduces a novel technique to measure the TOC and Tg of optical polymers which can be difficult to determine using traditional methods such as differential scanning calorimetry (DSC) after fabrication into photonic device constructs. The findings demonstrate that CHIPs exhibit low thermo-optic (TO) effects, making them exceptionally well-suited for the development of thermally stable photonic integrated circuits. The work reports the first fabrication of polymeric phase-shifted Bragg gratings with a new class of high refractive optical polymers, chalcogenide hybrid inorganic/organic polymers possessing very high sulfur content. This photonic construct enables the first measurement of the thermo-optic coefficient of these new optical polymers. image
Multiple relaxation times are used to capture the numerous stress relaxation modes found in bulk polymer melts. Herein, inverse vulcanization is used to synthesize high sulfur content (≥50 wt%) polymers that only need a single relaxation time to describe their stress relaxation. The S-S bonds in these organopolysulfides undergo dissociative bond exchange when exposed to elevated temperatures, making the bond exchange dominate the stress relaxation. Through the introduction of a dimeric norbornadiene crosslinker that improves thermomechanical properties, we show that it is possible for the Maxwell model of viscoelasticity to describe both dissociative covalent adaptable networks and living polymers, which is one of the few experimental realizations of a Maxwellian material. Rheological master curves utilizing time-temperature superposition were constructed using relaxation times as nonarbitrary horizontal shift factors. Despite advances in inverse vulcanization, this is the first complete characterization of the rheological properties of this class of unique polymeric material.
A polymerization methodology is reported using sulfur monochloride (S2Cl2) as an alternative feedstock for polymeric materials. S2Cl2 is an inexpensive petrochemical derived from elemental sulfur (S8) but has numerous advantages as a reactive monomer for polymerization vs S8. This new process, termed sulfenyl chloride inverse vulcanization, exploits the high reactivity and miscibility of S2Cl2 with a broad range of allylic monomers to prepare soluble, high molar-mass linear polymers, segmented block copolymers, and crosslinked thermosets with greater synthetic precision than achieved using classical inverse vulcanization. This step-growth addition polymerization also allows for preparation of a new class of thiol-free, inexpensive, highly optically transparent thermosets (α = 0.045 cm-1 at 1310 nm), which exhibit among the best optical transparency and low birefringence relative to commodity optical polymers, while possessing a higher refractive index (n > 1.6) in the visible and near-infrared spectra. The fabrication of large-sized optical components is also demonstrated.
Optical polymer‐based integrated photonic devices are gaining interest for applications in optical packaging, biosensing, and augmented/virtual reality (AR/VR). The low refractive index of conventional organic polymers has been a barrier to realizing dense, low footprint photonic devices. The fabrication and characterization of integrated photonic devices using a new class of high refractive index polymers, chalcogenide hybrid inorganic/organic polymers (CHIPs), which possess high refractive indices and lower optical losses compared to traditional hydrocarbon‐based polymers, are reported. These optical polymers are derived from elemental sulfur via the inverse vulcanization process, which allows for inexpensive monomers to be used for these materials. A facile fabrication strategy using CHIPs via lithography is described for single‐mode optical waveguides, Y junction splitters, multimode interferometers (MMIs), and high Q factor ring resonators, along with device characterization. Furthermore, propagation losses of 0.4 dB cm −1 near 1550 nm wavelength, which is the lowest measured loss in non‐fluorinated optical polymer waveguides, coupled with the benefits of low cost materials and manufacturing are reported. Ring resonators with Q factor on the order of 6 × 10 4 and cavity finesse of 45, which are some of the highest values reported for optical polymer‐based ring resonators, are also reported.
The production of elemental sulfur from petroleum refining has created a technological opportunity to increase the valorization of elemental sulfur by the synthesis of high-performance sulfur-based plastics with improved optical, electrochemical, and mechanical properties aimed at applications in thermal imaging, energy storage, self-healable materials, and separation science. In this Perspective, we discuss efforts in the past decade that have revived this area of organosulfur and polymer chemistry to afford a new class of high-sulfur-content polymers prepared from the polymerization of liquid sulfur with unsaturated monomers, termed inverse vulcanization.
The production of elemental sulfur from petroleum refining has created a technological opportunity to increase the valorization of elemental sulfur by the creation of high-performance sulfur based plastics with improved thermomechanical properties, elasticity and flame retardancy. We report on a synthetic polymerization methodology to prepare the first example of sulfur based segmented multi-block polyurethanes (SPUs) and thermoplastic elastomers that incorporate an appreciable amount of sulfur into the final target material. This approach applied both the inverse vulcanization of S 8 with olefinic alcohols and dynamic covalent polymerizations with dienes to prepare sulfur polyols and terpolyols that were used in polymerizations with aromatic diisocyanates and short chain diols. Using these methods, a new class of high molecular weight, soluble block copolymer polyurethanes were prepared as confirmed by Size Exclusion Chromatography, NMR spectroscopy, thermal analysis, and microscopic imaging. These sulfur-based polyurethanes were readily solution processed into large area free standing films where both the tensile strength and elasticity of these materials were controlled by variation of the sulfur polyol composition. SPUs with both high tensile strength (13–24 MPa) and ductility (348 % strain at break) were prepared, along with SPU thermoplastic elastomers (578 % strain at break) which are comparable values to classical thermoplastic polyurethanes (TPUs). The incorporation of sulfur into these polyurethanes enhanced flame retardancy in comparison to classical TPUs, which points to the opportunity to impart new properties to polymeric materials as a consequence of using elemental sulfur.
The critical role of nanoparticle dispersion on Faraday rotator activity was studied, revealing new routes for fabricating “plastic garnets” as low cost alternatives to existing inorganic materials for optical isolation and magnetic sensing.
SWCNTs were individually dispersed in ethylne glycol (EG)viamild bath-type sonication using quaternized poly(furfuryl methacrylate)-co-(2-(dimethylamino)ethyl methacrylate) p(FMA-co-QDMAEMA) as a dispersing agent. QDMAEMA, which has alkyl groups, was more favorable to the dispersion ability of single walled carbon nanotubes (SWCNTs). The dispersion mechanism of SWCNTs in EGviahelical wrapping of polymer chains along their sidewalls was suggested based on transmission electron microscopic observation.
AbstractOptical technologies in the long‐wave infrared (LWIR) spectrum (7–14 μm) offer important advantages for high‐resolution thermal imaging in near or complete darkness. The use of polymeric transmissive materials for IR imaging offers numerous cost and processing advantages but suffers from inferior optical properties in the LWIR spectrum. A major challenge in the design of LWIR‐transparent organic materials is that nearly all organic molecules absorb in this spectral window which lies within the so‐called IR‐fingerprint region. We report on a new molecular‐design approach to prepare high refractive index polymers with enhanced LWIR transparency. Computational methods were used to accelerate the design of novel molecules and polymers. Using this approach, we have prepared chalcogenide hybrid inorganic/organic polymers (CHIPs) with enhanced LWIR transparency and thermomechanical properties via inverse vulcanization of elemental sulfur with new organic co‐monomers.
Page 955, The third author’s name should be corrected as follows: Minho Kwon1, Taeheon Lee1, Young Sil Lee2, Jong Hun Han*,3, Hyun-jong Paik*,1
A polyring capable of reversible growth and dissociation is synthesized from a tricyclic polystyrene (PS) prepared by combining atom transfer radical polymerization of a 4-arm star-shaped PS and azide-alkyne click reactions. In the preparation of the tricyclic PS, a coupling agent containing a disulfide linkage is used in the click cyclization reaction. The reduction of the disulfide linkage in the tricyclic PS results in an 8-shaped PS with thiol groups which on oxidation leads to a high molecular weight polyring. The topology transformation between the polymers occurs via reversible redox reaction of disulfide/thiol. The high molecular weight of the polyring is realized due to the formation of flexible S-S linkage between the 8-shaped PSs. Their structures are confirmed by FT-IR, H-1 NMR, SEC, and MALDI-TOF MS analyses. In addition, molecular weight control of the polyring according to polymer concentration has been confirmed through SEC analysis.
We report covalent bioconjugation of N-hydroxysuccinimidyl-end-functionalized polystyrene (NHS-PSt) with primary amino groups of lysine residues in protein to form in situ core-shell polymer-protein hybrid spherical nanostructures. For this, we synthesized NHS-PSt by atom transfer radical polymerization (ATRP) using N-hydroxysuccinimidyl-2-bromo-2-methylpropionate initiator. The polymer was characterized by gel permeation chromatography and H-1 NMR. For bioconjugation, NHS-PSt dissolved in DMF was added slowly to deionized water containing protein at pH 8 at room temperature in a glass vial. Self-assembled protein-polymer hybrid core-shell spherical nanostructures were characterized using DLS, TEM and confocal microscope studies. The stability of hybrid nanostructures was also studied over time.
We describe a polymer-templated protein nanoball (PTPNB) system as an in-situ platform for the preparation of polymer-protein core-shell capsules containing hydrophobic cargos. These structures boast high protein activity through soft immobilization and maintain a consistent protein orientation through a specific interaction between the protein and polymer. We demonstrate the potential of this PTPNB system through bio-conjugation, encapsulation, and size-control of nanoballs in a one-pot process, and furthermore characterize the effects of nanoball size on endocytosis.
The generation of virus-mimetic nanoparticles has received much attention in developing a new vaccine for overcoming the limitations of current vaccines. Thus, a method, encompassing most viral features for their size, hydrophobic domain and antigen display, would represent a meaningful direction for the vaccine development. In the present study, a polymer-templated protein nanoball with direction oriented hemagglutinin1 on its surface (H1-NB) was prepared as a new influenza vaccine, exhibiting most of the viral features. Moreover, the concentrations of antigen on the particle surface were controlled, and its effect on immunogenicity was estimated by in vivo studies. Finally, H1-NB efficiently promoted H1-specific immune activation and cross-protective activities, which consequently prevented H1N1 infections in mice.
Living and dead chains of a polystyrene synthesized by atom transfer radical polymerization were separated and characterized by high performance liquid chromatography (HPLC), size exclusion chromatography (SEC), NMR, and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The bromine end group in the living chain was quantitatively converted to a hydroxyl end group via first azidation and subsequent copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction with propargyl alcohol. The living chains bearing a polar end group are fully resolved from the unmodified dead chains by HPLC separation using a bare silica stationary phase. Molecular weight distributions (MWD) of the living and dead chain are characterized by SEC and MALDI-MS. The MWD of the living chains is close to a Poisson distribution. Interestingly, the elution peak of the living chains in the HPLC separation split into two. The peak split is attributed to the diastereomeric structure of the chain end by NMR and MALDI-MS analyses.
This paper presents a fabrication method of hollow polymeric nanocapsules (HPNCs). The HPNCs were examined to reduce light trapping in an organic light emitting diodes (OLED) device by increasing the refractive index contrast. They were continuously fabricated by the sequential process of self-assembly and photo-crosslinking of an amphiphilic block copolymer of SBR-b-PEGMA, poly(styrene-r-butadiene)-b-poly(poly(ethylene glycol) methyl ether methacrylate) in a flow-focusing microfluidic device. After the photo-crosslinking process, the produced HPNCs have a higher resistance to water and organic solvents, which is applicable to the fabrication process of optical devices. The morphology and hollow structure of the produced nanocapsules were determined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Also, their size control was examined by varying the ratio of inlet flow rates and the morphological difference was studied by changing the polymer concentration. The size was measured by dynamic light scattering (DLS). The refractive index of the layer with and without the HPNCs was measured, and a lower refractive index was obtained in the HPNCs-dispersed layer. In future work, the light extraction efficiency of the HPNCs-dispersed OLED will be examined.
Highly flexible, durable, and transparent conducting films are fabricated from the de-bundled SWCNTs in aqueous solutions of SPES with high conductivity (125 Ω sq−1) and good transmittance (87%) without adopting any binder or post treatment techniques.