Polymeric Optical Materials Research Articles

Thermal and optical properties, and aggregated structure of poly(substituted methylene)s produced by radical polymerization of fumarates containing fluorine-substituted alkyl ester groups

Fluoropolymers have excellent heat, oxidation, and chemical resistances as well as low dielectric constant and dielectric loss, and are often used as highly functional optical polymer materials. In this study, we conducted the radical polymerization and copolymerization of asymmetric dialkyl fumarates, in which a bulky alkyl group is introduced into one ester group and a trifluoroethyl or hexafluoroisopropyl group is into another ester group. We successfully synthesized high-molecular-weight poly(dialkyl fumarate)s (PDRF) with a poly(substituted methylene) structure containing fluorine atoms in the side chain, and evaluated their structure and physical properties. First, the effect of fluorine substitution on the radical polymerization and copolymerization reactivity was examined. We also evaluated the thermal and optical properties of the fluorine-containing PDRFs and clarified the role of the fluorine substitution for increasing the β transition temperatures and reducing the refractive indices. Furthermore, the higher-order structure of the PDRFs in the solid state was analyzed by wide-angle X-ray scattering (WAXS) measurement in order to discuss the aggregation of the rigid PDRF chains and a possibility for the formation of a phase-separated microstructure by the fluorine-containing side chains.

Infrared microlens formation on chalcogenide polymer surface via femtosecond laser pulse ablation

In this study, we introduced micro-optical surface formation via femtosecond (fs) laser pulse scanning to chalcogenide polymer (ChP), a promising material for cost-effective infrared applications. Employing this method, we successfully fabricated a large-area poly(sulfur-random-(1,3-diisopropenylbenzene)) (S-r-DIB) microlens array (MLA) component. Each micro-concave spherical surface was crafted with a single fs laser pulse, serving as a micro-concave lens surface. We achieved a quasi-periodic MLA sample with over 2 × 105 micro-lenslets within a 10 mm × 10 mm footprint. Additionally, precise locating of laser pulse irradiation enabled us to create a hexagonal MLA with a filling factor over 37 %. Morphological investigations and imaging tests confirmed the adequate surface quality of the fabricated components, with its uniformity revealed by the virtual foci grid in near infrared region. To elucidate the forming conditions and mechanisms, we studied the evolution of surface morphology under various laser irradiation conditions. Laser induced damage thresholds of S70-r-DIB30 were experimentally determined for both 800 nm and 400 nm wavelengths under single- and multi-pulse irradiation scenarios. We identified the optimal fabrication fluence window as 115–205 mJ/cm2 with 800 nm single-pulse irradiation. The bandgap of the S70-r-DIB30 was estimated as 2.06 eV, and energy band analysis confirmed distinctions in ablation morphology. Furthermore, we investigated sub-surface morphology evolution using orthogonal ultrafast pump–probe imaging, revealing diversity compared to traditional inorganic and polymeric optical materials due to differing absorption and etching mechanisms. The elastic wave velocity of 3.2 km/s in this ChP and etching velocity of 0.7 μm/pulse were experimentally determined. These findings deepen our understanding of ChP material interaction with fs lasers, offering insights for potential applications such as surface engineering, substrate cutting, and micro-structure formation.

Deposition and Localization of Polishing Powder Wear Nanoparticles on the Processed Surface of Polymeric Optical Materials

Deposition and Localization of Polishing Powder Wear Nanoparticles on the Processed Surface of Polymeric Optical Materials

Characterization of the optical and electronic properties of chalcogenide hybrid inorganic/organic polymer thin films

Chalcogenide hybrid inorganic/organic polymers (CHIPs) are a new class of optical polymeric materials for imaging and photonic applications due to their high refractive indices and high optical transmission at visible and infrared wavelengths. In this study, we characterize these polymers to study the refractive index and delve into the electronic properties by way of measurements of their dielectric constants. Ellipsometry is used to determine the refractive indices for wavelengths from 500 nm to 12 µm, while we use capacitance measurements on thin film capacitors with a range of areas to find the dielectric constant. The results are in line with expectations based on the sulfur composition of the polymers-indices range from 1.7 to 1.85, and dielectric constants range from 2.6 to 3. With these measurements, these sulfur polymer materials are established to be good candidates for optical and photonic applications, particularly with respect to telecommunications. The dielectric constants suggest that applications such as electro-optic devices and capacitors may also be viable.

Polishing of precision parts from polymer optical materials

The conducted research concerns the study of the laws influence of the physicochemical properties the processed material and the polishing dispersion system on the productivity of removing the processed material and the roughness the processed surfaces during the polishing of polymeric optical materials. The research was carried out according to a special methodology, the parameters of the roughness of the polished surfaces were determined using elements of computer modeling. As a result of the study, it was determined that during the polishing precision parts made of polystyrene and polymethyl methacrylate with the help of a dispersed system of micro- and nanoparticles non-abrasive organic materials, the removal performance of the processed material and the parameters the roughness of the treated surfaces are achieved, which meet the requirements extending to the optical surfaces.

Interaction of Sludge Particles and Wear Particles of Polishing Powder in the Process of Polishing of Polymeric Optical Materials

Interaction of Sludge Particles and Wear Particles of Polishing Powder in the Process of Polishing of Polymeric Optical Materials

Solar Thermal Textiles for On-Body Radiative Energy Collection Inspired by Polar Animals.

Humans use textiles to maintain thermal homeostasis amidst environmental extremes but known textiles have limited thermal windows. There is evidence that polar-dwelling animals have evolved a different mechanism of thermoregulation by using optical polymer materials to achieve an on-body "greenhouse" effect. Here, we design a bilayer textile to mimic these adaptations. Two ultralightweight fabrics with complementary optical functions, a polypropylene visible-transparent insulator and a nylon visible-absorber-infrared-reflector coated with a conjugated polymer, perform the same putative function as polar bear hair and skin, respectively. While retaining familiar textile qualities, these layers suppress dissipation of body heat and maximize radiative absorption of visible light. Under moderate illumination of 130 W/m2, the textile achieves a heating effect of +10 °C relative to a typical cotton T-shirt which is 30% heavier. Current approaches to personal radiative heating are limited to absorber/reflector layer optimization alone and fail to reproduce the thermoregulation afforded by the absorber-transmitter structure of polar animal pelts. With increasing pressures to adapt to a rapidly changing climate, our work leverages optical polymers to bridge this gap and evolve the basic function of textiles.

Roughness of Polished Surfaces of Optoelectronic Components Made of Polymeric Optical Materials

Roughness of Polished Surfaces of Optoelectronic Components Made of Polymeric Optical Materials

Synthesis and characterization of a polystyrene-type polymer bearing a cyclic perfluoroalkylene group

Perfluoroalkyl-containing aromatic compounds are predicted to have fascinating material properties. In this work, a styrene derivative bearing a cyclic perfluoroalkylene group, –(CF2)4–, was synthesized and polymerized to afford the corresponding polymer. The styrene derivative was obtained via the Ullmann coupling of I–(CF2)4–I with 3′-bromo-4′-iodoacetophenone, NaBH4 reduction of the ketone moiety, and dehydration using P4O10. Free-radical polymerization (FRP) of the styrene derivative afforded polymer with number-average molecular weight (Mn) and dispersity index (DI) of 1.1 × 104 and 3.1, respectively. The thermal stability of the synthesized polymer (Td10% 359 °C, Tg 149 °C) was greater than the previously reported n-C4F9-substituted polystyrene (Td10% 296 °C, Tg 19 °C). The increased thermal stability of the newly synthesized polymer is hypothesized to arise from the lack of terminal CF3 moieties. The cyclic perfluoroalkylene-substituted polystyrene exhibited hydro- and oleo-phobicities comparable to those of the n-C4F9-substituted polystyrene, suggesting that the introduction of cyclic perfluoroalkylene groups instead of the commonly used Rf groups may have the potential to develop thermo-resistant polymers with hydro- and lipo-phobicity. Thew newly synthesized polymer is suitable for a variety of applications requiring high-Tg optical polymeric materials.

Thermal Paper and Time Temperature Integrators Made From a Structural Colored Polymer Crosslinked With Hydrogen Bonded Cyclohexanoic Acid Derivatives

AbstractHydrogen‐bonded cyclohexanoic derivatives are applied in a structural colored cholesteric liquid crystal (CLC) helical polymer that demonstrates an extraordinary dual thermal response. Integration of the dynamic hydrogen‐bonded cyclohexanoic acid derivatives in the CLC polymer as supramolecular crosslinks yields an immediate and irreversible loss of the green structural color upon exposure to temperatures above the cholesteric‐to‐isotropic transition temperature (TNI) caused by the helical order loss. Exposure to temperatures below the TNI yields a gradual irreversible red color shift of the reflected wavelength over broad temperature and time ranges. Most likely due to polymerization confinement in combination with the dynamics of the carboxylic acid hydrogen bonds, helical unwinding takes place over time causing the red shift of the reflected wavelength. The temperature response can be programmed by altering the chemical composition of the liquid crystal mixture. Furthermore, the green, structural color of the polymer can also be easily changed making it possible to print different colored indicators combined with different respective temperature responses on a single substrate. The printed optical sensors can be easily delaminated by dissolving the non‐covalent crosslinked polymer. Such optical polymer materials are attractive for easy processable time–temperature integrators and thermal paper.

Prediction of birefringence for polymer optical products based on a novel molecular chain orientation model

Optical polymer materials are widely used in aerospace, electronics, and other engineering fields, which have strict requirements on optical properties such as the birefringence of products. The present birefringence calculation method is based on the stress-birefringence law and is still difficult in accurate prediction, owing to extremely difficulty in predict residual stress. Actually, the birefringence of polymer optical products is essentially caused by the molecular chain orientation. Thus, a quantitative mathematical model between molecular orientation and birefringence is proposed in this study. The coupling simulation of the macroscopic flow field and microscopic orientation is realized through internal stress. The accuracy of the proposed model is verified by the polarized Raman and birefringence distribution experimental results. Compared with the stress-birefringence method, the proposed model and numerical method can more accurately simulate molecular orientation and birefringence. Meanwhile, the simulated average orientation degree in the thickness direction under different melt and mold temperatures are compared with the measured results, which verifies the effectiveness of the proposed model and simulation method at different process conditions.

Synthesis and copolymerization of new methacrylic monomers for the creation of nonlinear optical polymer materials

Synthesis and copolymerization of new methacrylic monomers for the creation of nonlinear optical polymer materials

Planar light-wave circuit-based switchable LP11a-LP11b mode rotator.

A simple planar light-wave circuit-based switchable LP11a-LP11b mode rotator for reconfigurable mode division multiplexing is proposed, which consists of a polymer waveguide and an electrode heater located on the waveguide. Because of the asymmetric refractive index distribution in the horizontal and vertical directions, induced by the thermo-optic effect, mode rotation between the LP11a and LP11b modes can be achieved when the heater is ON but there can be no mode rotation when the heater is OFF. Numerical simulations show that our well-designed mode rotator with optical polymer materials, which has a length of 2750 µm, can achieve a mode conversion efficiency (MCE) larger than 84% over the entire C+L band (1530-1610 nm) and a maximum MCE of 96% at 1550 nm. The switching electric power is 161.5 mW. The calculated temperature within the waveguide core is from 186°C (close to the heater) to 86°C (away from the heater).

Study of Control for Mechanical and Optical Properties of Polymeric Optical Materials Considering Molecular Orientation and Dynamics

Study of Control for Mechanical and Optical Properties of Polymeric Optical Materials Considering Molecular Orientation and Dynamics

Application features of optical polymers in optical systems design

Subject of Research.The paper considers analysis of mechanical and optical properties of modern optical polymer materials. We present the result of design and quality characteristics of small magnification telescopic glasses, made of modern optical polymers and intended for application in medicine, production of microelectronic circuits, and jewelry. Method. Calculation of telescopic glasses is carried out according to Galilei scheme on the basis of the automated method of aberration correction. The requirements are fulfilled concerning the necessity exception of additional accommodation of eyes at transition from observation with and without glasses, due to the object and image location in one plane. Main Results. The obtained optical system has diffraction image quality, and the mass of fully polymer glasses is two times lower than that of analogues made of glass. Practical Relevance. Modern optical polymers have advanced mechanical and optical properties, and create the perspective of glass component replacement with polymer ones and fabrication of fully polymeric optical systems with high quality characteristics. At the same time, manufacturing technologies of components made of optical polymers provides to obtain surfaces of complex shape (kinoforms, aspherics, and “freeforms”). Technical problems can be solved associated with the scaling of production, reducing of the assembly labor intensity, updating of the design, reducing of the mass and dimensional properties, and the cost of products.

The influence of different factors on exploitation properties of nonlinear optical polymeric materials based on an epoxy matrix doped with flavonoids

The paper is devoted to investigations of exploitation properties of nonlinear-optical (NLO) polymer film materials based on an epoxy matrix doped with flavonoids. Adhesion of the polymer films to a glass substrate is investigated. Also, the influence of photoinduced destruction on functional properties of these polymer composites by UV–Vis spectroscopy method is studied. Effect of various microorganisms such as mold fungi of Aspergillus niger (A. niger) and Pinicillum chrysogenum (P. chrysogenum) species on the polymer NLO materials are analyzed by evaluation of the fungistatic effect and fungicidal resistance and using the FTIR spectroscopy. As a result it is established that the NLO polymer film materials based an epoxy matrix doped with flavonoids have a very good adhesion to the glass substrate, and they are stable to the photoinduced destruction. These materials do not have the fungistatic effect but they demonstrate some fungicidal resistance. This phenomenon is explained by the presence of flavonoids, which are natural antiseptics.

Synthesis and Characterization of a Novel Erbium Doped Poly(vinyl alcohol) Films for Multifunctional Optical Materials

Polymer films based on poly vinyl alcohol (PVA) doped with different contents (0, 4, 8, 16, 20 and 28) wt% of Erbium(III) ions were synthesized by the simple solution casting technique. The structural characteristics of the films were studied by X-ray diffraction pattern (XRD), Fourier transform infrared (FT-IR) spectroscopy and atomic force microscopy measurements (AFM) measurement whereas the optical behavior of these films have been investigated using UV–Vis-NIR spectroscopy and photoluminescence measurements. The structural parameters of the interplanar (d) spacing, crystallite length (L) and the average interchain separation determined from the XRD and the absorption bands of the active IR groups recorded in FT-IR spectra indicate bonding of positively charged Er3+ ions with negatively charged OH groups of the PVA chains. The average cluster size (D) of the samples estimated from AFM data shows larger values than that obtained from XRD measurements. The optical gaps obtained from absorption spectra fitting and Tauch relations are approximately equal and slightly decreased by Er3+ ions incorporation in the PVA matrix whereas the high frequency refractive indices estimated according to Moss and Dimitrov formulae showing small increase. Three intense peaks of 607 nm, 733 nm and 783 nm wavelengths due to energy levels transitions of erbium were recorded in the photoluminescence spectra PVA–Er3+. The collected data support consideration of PVA–Er3+ films as a promising optical polymer material in microptics, planar polymer waveguides, polymer optical fiber and polymer light emitting diodes applications.

High-refractive index acrylate polymers for applications in nanoimprint lithography

The development of polymeric optical materials with a higher refractive index, transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses, image sensors, and organic light-emitting diodes. Most acrylates have a low refractive index (around 1.50) which does not meet the high performance requirements of advanced optical materials. In this research, three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers. All of the polymers reveal good optical properties including high transparency (≥90%) in the visible spectrum region and high refractive index values (1.6363) at 550 nm. Moreover, nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography. These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.

Cascaded-Microrings Biosensors Fabricated on a Polymer Platform.

Polymer-based single-microring biosensors usually have a small free spectral range (FSR) that hampers the tracing of the spectrum shifting in the measurement. A cascade of two microring resonators based on the Vernier effect, is applied in this article in order to make up for this defect. A small FSR difference between the reference microring and the sensing microring is designed, in order to superpose the periodic envelope signal onto the constituent peaks, which makes it possible to continuously track the spectrum of the sensor. The optical polymer material, Ormocore, which has a large transparent window, is used in the fabrication. The biosensor is fabricated by using an UV-based soft imprint technique, which is considered to be cost-effective and suitable for mass production. By optimizing the volume ratio of Ormocore and the maT thinner, the device can be fabricated almost without a residual layer. The device works at a wavelength of 840 nm, where water absorption loss is much lower than at the infrared wavelengths. A two-step fitting method, including single-peak fitting and whole-envelope fitting, is applied in order to trace the spectral shift accurately. Finally, the two-cascaded-microrings biosensor is characterized, and the obtained FSR is 4.6 nm, which is 16 times larger than the FSR of the single microring biosensor demonstrated in our previous work. Moreover, the sensitivity can also be amplified by 16-fold, thanks to the Vernier effect.

Вплив внутрішніх напружень на хвильові процеси та поглинання ультразвуку при зварюванні

Using the bilinear approximation of the total strain tensor for an elastic wave process in the pre-sence of internal static stresses and deformations in welded optical polymeric materials, their influence on the process characteristics and ultrasound absorption has been theoretically investigated. For the case of a plane elastic wave and axially symmetric static stresses, a two-dimensional system of wave equations for the longitudinal and transverse wave components is obtained. It has been established that only inhomogeneous internal stresses and deformations lead to the appearance of a weak coupling between the components of the wave and a change in their amplitudes, as well as to the weakening of the longitudinal (acoustic) component of the elastic wave. For a simple example of a point force action on the surface, calculations are made of the decrements of ultrasound attenuation by amplitude in the meridian planes. It is shown that for sufficiently large gradients of static deformations near the pressing region of the welded parts, a region of maximum (resonance) absorption of ultrasound may be formed, whose dimensions are comparable to the effective length, which depends on the square root of the ratio of the applied pressing force to the modulus of elasticity of the material. This contributes to the localization of the ultrasound absorption region.