Optical technologies in the long-wave infrared (LWIR) spectrum (7-14 mm) 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 windoww hichl ies within the so-called IR-fingerprint region. We report on an ew molecular-design approacht o prepare high refractive index polymers with enhanced LWIR transparency.Computational methods were used to accelerate the design of novel molecules and polymers.U sing this approach,w eh ave 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.

The first example of a sulfur copolymer with amine groups poly(sulfur-random-vinylaniline) was synthesized and successfully post-functionalized to improve the thermomechanical properties of these materials.

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.

The Faraday effect is a magneto-optical (MO) phenomenon by which the polarization direction of linearly polarized light is rotated when passing through a transparent material with the application of a magnetic field along the direction of light propagation. The magnitude of the angle by which light is rotated at specific wavelengths, temperatures, and applied magnetic fields is directly proportional to the Verdet constant, which is an intrinsic bulk property of an optically transparent material. A high Verdet constant is desired for MO applications such as optical isolators, sensors, or modulators to reduce the path length required to obtain large optical rotation with modest magnetic fields to enable device miniaturization and overall cost reduction. MO material development has been ongoing for nearly the past two centuries, from which a wide range of materials have emerged. Herein, we review the development of high Verdet constant MO materials across many material classes, with an emphasis on recent developments of higher Verdet constant polymeric and polymer-nanocomposite materials. Inorganic materials have primarily been used for Faraday rotation systems which initially focused on the use of amorphous glasses and has since expanded into MO active crystals, ceramics, ferrofluids, organic small molecules, synthetic polymers, and polymer–nanoparticle nanocomposites. Although the most widely used materials for MO applications, hard matter based on inorganic materials typically possess Verdet constants on the order of 103–104 °/T·m at room temperature when measured in the visible and NIR ranges. More recent work has focused on using soft matter alternatives composed of organic small molecules, polymers, and polymer–nanoparticle nanocomposites which afford higher Verdet constants ranging from 104 to 106 °/T·m at room temperature. The current Review aims to discuss inorganic, organic, and hybrid high Verdet constant materials, which has been previously complicated by nonuniformity in the units and sampling conditions used for these MO measurements.

We present here high sensitivity attenuated total reflectance (ATR) spectroelectrochemical studies of electron injection (reduction) into surface-tethered, submonolayer to monolayer coverages of CdSe quantum dots (QDs) linked to indium–tin oxide (ITO) electrodes using a strong X-type bifunctional phosphonic acid (PA) surface linker, octanediphosphonic acid (ODiPA). Estimates of conduction band energies (E CB) were obtained from the onset of absorbance bleaching as a function of QD diameter (3.2–6.4 nm) and as a function of the supporting electrolyte (LiClO4) concentration. For CdSe QDs created from combinations of moderately strong stearic acid, hexadecylamine, trioctylphosphine oxide, and trioctylphosphine ligands, surface-tethering was accompanied by decreases in QD diameter and loss of up to 25% volume for the largest QDs. For QDs prepared with PA ligands, followed by aggressive (3×) pyridine exchange to produce QDs with weak capping ligands, no size reduction was observed as a result of adsorption to the ODiPA/ITO surface. For both types of tethered CdSe QDs, significant stabilization of the reduction product of the surface-tethered QD was observed with ca. 700 meV lowering of E CB relative to estimates of E CB obtained from our recent in vacuuo UV-photoemission studies of bare CdSe QDs tethered to Au surfaces. A sizeable fraction of that stabilization is proposed to arise from the tethering of these asymmetric QDs to a complex, high dielectric constant interface region. At least 200 meV of the stabilization arises from concentration-dependent charge screening by the solution counter ion (Li+), with no evidence for the incorporation of Li+ as a result of the electron injection process. The overall stabilization in the reduced form of these tethered QDs is larger than seen for previous spectroelectrochemical studies of QD reduction, in solution, tethered at higher coverages to transparent electrodes, or as electrophoretically deposited multilayer QD thin films. This waveguide ATR spectroelectrochemical approach to estimating energetics for QDs tethered to semiconductor or oxide substrates at low surface coverages is likely to be relevant for a wide array of energy conversion and energy storage processes using nanomaterials and may be especially useful for studying the effects of surface coverage, type of surface linker, contacting solvent/electrolytes, and adsorbed molecular reactants.

The Faraday effect and Faraday rotation are important magneto-optical phenomena, where the polarization direction of linearly polarized light can be controlled by the application of a magnetic field along the direction of light propagation. Transmissive, magneto-optical materials of sufficient thickness can achieve large Faraday rotation angles, where the intrinsic magneto-optical activity of a substance is described by the Verdet constant of the material. High Verdet constant materials are critical for a wide range of magneto-optical devices, such as optical isolators, optical circulators, and modulators. State of the art in Faraday rotation devices such as optical isolators most widely employs inorganic garnet materials, which possess excellent optical transparency and robust thermomechanical properties. However, these materials possess fairly low Verdet constants (∼10 3−4 °/T• m). In this report, we demonstrate the use of polymer-coated magnetic cobalt nanoparticles (CoNPs) to afford ultrahigh Verdet constant materials (−2.2 × 10 5 to −2.5 × 10 6 °/T•m at 1310 nm) with 2−3 orders of magnitude greater Verdet constants than classical inorganic garnets and earlier polymer-magnetic NP materials. Furthermore, the polymer coating on magnetic NPs affords excellent colloidal dispersion that enables solution or melt processing of these materials into multilayered thin films or free-standing films. The ability to prepare CoNPs of varying sizes further enabled structure−property correlations of magnetic NP size with both bulk magnetic and magnetic-optical properties, which previously has not been conducted.

New amine functional sulfur prepolymers were synthesized from inexpensive poly(sulfur‐random‐styrene) and 1,3‐meta‐phenylenediamine (PDA) via a proposed electrophilic aromatic substitution (SEAr) reaction. These chalcogenide hybrid inorganic/organic polymer resins show improved solubility in organic solvents. The aromatic amine functional groups were utilized to react with epoxides on polyhedral oligomeric silsesquioxanes through post‐polymerization modification which resulted in crosslinked sulfur polymers.

Cholesteric liquid crystals (CLC) are molecules that can self-assemble into helicoidal superstructures exhibiting circularly polarized reflection. The facile self-assembly and resulting optical properties makes CLCs a promising technology for an array of industrial applications, including reflective displays, tunable mirror-less lasers, optical storage, tunable color filters, and smart windows. The helicoidal structure of CLC can be stabilized via in situ photopolymerization of liquid crystal monomers in a CLC mixture, resulting in polymer-stabilized CLCs (PSCLCs). PSCLCs exhibit a dynamic optical response that can be induced by external stimuli, including electric fields, heat, and light. In this review, we discuss the electro-optic response and potential mechanism of PSCLCs reported over the past decade. Multiple electro-optic responses in PSCLCs with negative or positive dielectric anisotropy have been identified, including bandwidth broadening, red and blue tuning, and switching the reflection notch when an electric field is applied. The reconfigurable optical response of PSCLCs with positive dielectric anisotropy is also discussed. That is, red tuning (or broadening) by applying a DC field and switching by applying an AC field were both observed for the first time in a PSCLC sample. Finally, we discuss the potential mechanism for the dynamic response in PSCLCs.