Refractive Index Engineering of Polymer Nanocomposites Prepared by End-grafted Polymer Chains onto Inorganic Nanoparticles

2011 ◽  
Vol 1359 ◽  
Author(s):  
Peng Tao ◽  
Anand Viswanath ◽  
Yu Li ◽  
Atri Rungta ◽  
Brian C. Benicewicz ◽  
...  
Keyword(s):  
Refractive Index ◽  
Polymer Nanocomposites ◽  
Polymer Brushes ◽  
Raft Polymerization ◽  
Weight Percent ◽  
High Refractive Index ◽  
Inorganic Nanoparticles ◽  
Polymer Chains ◽  
Hybrid Particles ◽  
Grafted Polymer

ABSTRACTTransparent polymer nanocomposites with high refractive index were prepared by grafting polymer chains onto TiO2 nanoparticles. Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to prepare poly(methyl methacrylate) (PMMA) polymer brushes grafted from TiO2 nanoparticles. The refractive index of the hybrid material increased from 1.49 for neat PMMA to 1.6 by increasing the loading of TiO2 to 40 weight percent. UV-vis spectra showed that grafted particles had a transparency of more than 90% in the visible light range. The hybrid particles can be processed into transparent, high refractive index coatings and self-standing films. The grafted TiO2 nanoparticles can also be easily dispersed into a polymer matrix forming thick, robust transparent polymer nanocomposites.

scholarly journals Effect of Structure of Polymers Grafted from Graphene Oxide on the Compatibility of Particles with a Silicone-Based Environment and the Stimuli-Responsive Capabilities of Their Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 591 ◽  
Author(s):  
Monika Zygo ◽  
Miroslav Mrlik ◽  
Marketa Ilcikova ◽  
Martina Hrabalikova ◽  
Josef Osicka ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Graphene Oxide ◽  
Radical Polymerization ◽  
Polymer Brushes ◽  
Silicone Oil ◽  
Polymer Chains ◽  
Butyl Methacrylate ◽  
Raman Shift ◽  
Stimuli Responsive ◽  
Grafted Polymer

This study reports the utilization of controlled radical polymerization as a tool for controlling the stimuli-responsive capabilities of graphene oxide (GO) based hybrid systems. Various polymer brushes with controlled molecular weight and narrow molecular weight distribution were grafted from the GO surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The modification of GO with poly(n-butyl methacrylate) (PBMA), poly(glycidyl methacrylate) (PGMA), poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) and poly(methyl methacrylate) (PMMA) was confirmed by thermogravimetric analysis (TGA) coupled with online Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Various grafting densities of GO-based materials were investigated, and conductivity was elucidated using a four-point probe method. Raman shift and XPS were used to confirm the reduction of surface properties of the GO particles during SI-ATRP. The contact angle measurements indicated the changes in the compatibility of GOs with silicone oil, depending on the structure of the grafted polymer chains. The compatibility of the GOs with poly(dimethylsiloxane) was also investigated using steady shear rheology. The tunability of the electrorheological, as well as the photo-actuation capability, was investigated. It was shown that in addition to the modification of conductivity, the dipole moment of the pendant groups of the grafted polymer chains also plays an important role in the electrorheological (ER) performance. The compatibility of the particles with the polymer matrix, and thus proper particles dispersibility, is the most important factor for the photo-actuation efficiency. The plasticizing effect of the GO-polymer hybrid filler also has a crucial impact on the matrix stiffness and thus the ability to reversibly respond to the external light stimulation.

scholarly journals Precise growth of polymer brushes on silica-based nanocomposites via visible-light-regulated controlled radical polymerization

2019 ◽  
Vol 7 (11) ◽  
pp. 6173-6179 ◽  
Author(s):  
Xue Li ◽  
Sunjie Ye ◽  
Ya Huang ◽  
Jia Le Li ◽  
Tao Cai
Keyword(s):  
Physicochemical Properties ◽  
Visible Light ◽  
Radical Polymerization ◽  
Polymer Nanocomposites ◽  
Polymer Brushes ◽  
Controlled Radical Polymerization ◽  
Crucial Importance ◽  
Grafted Polymer ◽  
Precise Control

Precise control over molecular variables of grafted polymer brushes is of crucial importance for obtaining polymer nanocomposites with desirable architectures and physicochemical properties, yet it remains a significant synthetic challenge.

scholarly journals Highly Scattering Hierarchical Porous Polymer Microspheres with a High-Refractive Index Inorganic Surface for a Soft-Focus Effect

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2418
Author(s):  
Joonsik Yoon ◽  
Ji Hyun Lee ◽  
Jun Bae Lee ◽  
Jun Hyup Lee
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Tio2 Nanoparticles ◽  
High Refractive Index ◽  
Inorganic Materials ◽  
Porous Polymer ◽  
Hybrid Particles ◽  
Inorganic Hybrid ◽  
Hierarchical Porous ◽  
Focus Effect

Functional light scattering materials have received considerable attention in various fields including cosmetics and optics. However, a conventional approach based on optically active inorganic materials requires considerable synthetic effort and complicated dispersion processes for special refractive materials. Here, we report a simple and effective fabrication strategy for highly scattering hierarchical porous polymer microspheres with a high-refractive index inorganic surface that mitigates the disadvantages of inorganic materials, producing organic-inorganic hybrid particles with an excellent soft-focus effect. Hierarchical organic-inorganic hybrid particles were synthesized using the simple physical mixing of porous poly (methyl methacrylate) (PMMA) microparticles with different pore sizes and regularities as the organic core and titanium dioxide (TiO2) nanoparticles with different particle sizes as the inorganic shell. The polar noncovalent interactions between polar PMMA microspheres and the polar surface of TiO2 nanoparticles could induce the hierarchical core-shell structure of hybrid particles. The synthesized hybrid particles had increased diffuse reflectance properties of up to 160% compared with single inorganic particles. In addition, the light scattering efficiency and soft-focus effect could be increased further, depending on the size of the TiO2 nanoparticles and the pore characteristics of the PMMA microspheres. The proposed study can provide a facile and versatile way to improve the light scattering performance for potential cosmetics.

scholarly journals Swelling and durability performance of surface-grafted polymer brushes and brush gels

2021 ◽  
Vol 14 (1) ◽  
pp. 73-80
Author(s):  
Serkan Demirci ◽  
Selin Kinali-Demirci
Keyword(s):  
Polymer Brushes ◽  
Raft Polymerization ◽  
Water Contact ◽  
Swelling Properties ◽  
Grafted Polymer ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Cross Linker ◽  
The Stability ◽  
Durability Performance

Polymer brushes and brush gels were prepared by RAFT polymerization. Prepared surfaces were characterized by XPS, AFM, ellipsometry, and water contact angle measurements. The swelling properties and stability of surfaces were compared. It was determined that the swelling ratio decreased with increasing grafting density and cross-linker ratio for polymer brushes and brush gels, respectively. As a result, it was observed that cross-linked polymer brushes were more stable than polymer brushes, and the stability and swelling properties of polymer brushes could be controlled by cross-linking.

New Core/Shell Ta2O5-PMMA Nanocomposites for Applications as Polymer Waveguides

2007 ◽  
Vol 1056 ◽  
Author(s):  
Dorothée Vinga Szabó ◽  
Rolf Ochs ◽  
Sabine Schlabach ◽  
Eberhard Ritzhaupt-Kleissl ◽  
Thomas Hanemann
Keyword(s):  
Refractive Index ◽  
Polymer Nanocomposites ◽  
Near Infrared ◽  
Microwave Plasma ◽  
High Refractive Index ◽  
Organic Coating ◽  
Hybrid Nanoparticles ◽  
Core Shell ◽  
Polymer Waveguides ◽  
Shell Particles

ABSTRACTTo realize ceramic/polymer nanocomposites for polymer waveguides, PMMA-coated Ta2O5 nanoparticles are synthesized as core/shell particles. Therefor a gas-phase process is used: the Karlsruhe Microwave Plasma Process. The organic coating is supposed to reduce the agglomeration of the ceramic cores and should facilitate the incorporation into the polymer resin. TEM investigations of the nanoparticles exhibit crystalline and amorphous Ta2O5 with sizes around 3 to 6 nm, confirmed by electron diffraction. Although the polymer coating is not visible in TEM imaging, electron energy loss spectroscopy (EELS) exhibits a significant C-edge, proofing the organic coating. The Ta2O5/PMMA nanoparticles are incorporated with different weight fractions to a maximum of 1 wt% by a dissolver stirrer into PMMA resin. The optical properties (refractive index, transmission) are determined as a function of the nanoparticle content. Compared to the pure polymer, the refractive index of the modified composite, measured at 633 nm, is increased by 0.001 and 0.004 at 0.1 wt% and 0.7 wt%, respectively. A similar tendency is observed at 1550 nm. The transmission in the near infrared (NIR) is similar to that of PMMA up to a content of 0.3 wt%. At higher nanoparticle contents transmission is reduced. The reduction in transmission is due to the presence of agglomerates larger then 1/10 of the applied wavelength, confirmed by TEM. The concept of incorporating inorganic/organic hybrid nanoparticles with intrinsic high refractive index in polymer matrices is very promising. A suitable effect in refractive index for application of ceramic nanoparticle/polymer nanocomposites as polymer waveguides could be observed even with low particle concentration.

scholarly journals Preparation of High Refractive Index Composite Films Based on Titanium Oxide Nanoparticles Hybridized Hydrophilic Polymers

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 514 ◽  
Author(s):  
Makoto Takafuji ◽  
Maino Kajiwara ◽  
Nanami Hano ◽  
Yutaka Kuwahara ◽  
Hirotaka Ihara
Keyword(s):  
Refractive Index ◽  
Titanium Oxide ◽  
Polymer Matrix ◽  
High Refractive Index ◽  
Inorganic Nanoparticles ◽  
Water Soluble ◽  
Hydrophilic Polymers ◽  
Oxide Nanoparticles ◽  
Titanium Oxide Nanoparticles ◽  
Hydrogen Bond Formation

Optical materials with high refractive index (n) have been rapidly improved because of urgent demands imposed by the development of advanced photonic and electronic devices such as solar cells, light emitting diodes (LED and Organic LED), optical lenses and filters, anti-reflection films, and optical adhesives. One successful method to obtain high refractive index materials is the blending of metal oxide nanoparticles such as TiO2 and ZrO2 with high n values of 2.1–2.7 into conventional polymers. However, these nanoparticles have a tendency to agglomerate by themselves in a conventional polymer matrix, due to the strong attractive forces between them. Therefore, there is a limitation in the blending amount of inorganic nanoparticles. In this paper, various hydrophilic polymers such as poly(N-hydroxyl acrylamide) (pHEAAm), poly(vinyl alcohol), poly(ethylene glycol), and poly(acrylic acid) were examined for preparation of high refractive index film based on titanium oxide nanoparticle (TiNP) dispersed polymer composite. The hydrogen bonding sites in these hydrophilic polymers would improve the dispersibility of inorganic nanoparticles in the polymer matrix. As a result, pHEAAm exhibited higher compatibility with titanium oxide nanoparticles (TiNPs) than other water-soluble polymers. Transparent hybrid films were prepared by mixing pHEAAm with TiNPs and drop casting the mixture onto a glass plate. The refractive indices of the films were in good agreement with calculated values. The compatibility of TiNPs with pHEAAm was dependent on the surface characteristics of TiNPs. TiNPs with the highest observed compatibility could be hybridized with pHEAAm at concentrations of up to 90 wt%, and the refractive index of the corresponding film reached 1.90. The high compatibility of TiNPs with pHEAAm may be related to the hydrophilicity and amide and hydroxyl moieties of pHEAAm, which cause hydrogen bond formation on the TiO2 surface. The obtained thin film was slightly yellow due to the color of the original TiNP dispersion; however, the transmittance of the film was higher than 80% in the wavelength range from 480 to 900 nm.

scholarly journals High refractive index films of polymer nanocomposites

1993 ◽  
Vol 8 (7) ◽  
pp. 1742-1748 ◽  
Author(s):  
Lorenz Zimmennann ◽  
Martin Weibel ◽  
Walter Caseri ◽  
Ulrich W. Suter
Keyword(s):  
Refractive Index ◽  
Polymer Nanocomposites ◽  
Spin Coating ◽  
Volume Fraction ◽  
Polymeric Composite ◽  
High Refractive Index ◽  
Nanocomposite Films ◽  
Refractive Indices ◽  
Coating Process ◽  
Spin Coating Process

Solutions of PbS particles and gelatin were used for the preparation of nanocomposites by a spin-coating process. This allows for the preparation of nanocomposite films with controlled thickness, e.g., between 40 nm and 2 μm for a film containing 45 wt.% PbS. Surface roughness and film thickness were investigated by surface profilometry and scanning electron microscopy (SEM). The refractive index at 632.8 nm can be expressed by a linear function of the volume fraction of PbS in the range of 0 to 55 vol. % PbS. In this range, the refractive index increases from 1.5 to 2.5 with increasing PbS ratio and belongs, therefore, to the highest refractive indices known for polymeric composite materials.

Accelerated Discovery of High-Refractive-Index Polyimides via First-Principles Molecular Modeling, Virtual High-Throughput Screening, and Data Mining

2019 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Mojtaba Haghighatlari ◽  
Sai Prasad Ganesh ◽  
Chong Cheng ◽  
Johannes Hachmann
Keyword(s):  
Data Mining ◽  
Refractive Index ◽  
High Throughput ◽  
First Principles ◽  
High Throughput Screening ◽  
Large Scale ◽  
Computational Study ◽  
High Refractive Index ◽  
Structural Features ◽  
Learning Program

<div>We present a high-throughput computational study to identify novel polyimides (PIs) with exceptional refractive index (RI) values for use as optic or optoelectronic materials. Our study utilizes an RI prediction protocol based on a combination of first-principles and data modeling developed in previous work, which we employ on a large-scale PI candidate library generated with the ChemLG code. We deploy the virtual screening software ChemHTPS to automate the assessment of this extensive pool of PI structures in order to determine the performance potential of each candidate. This rapid and efficient approach yields a number of highly promising leads compounds. Using the data mining and machine learning program package ChemML, we analyze the top candidates with respect to prevalent structural features and feature combinations that distinguish them from less promising ones. In particular, we explore the utility of various strategies that introduce highly polarizable moieties into the PI backbone to increase its RI yield. The derived insights provide a foundation for rational and targeted design that goes beyond traditional trial-and-error searches.</div>

Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

2013 ◽  
Vol 28 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Yu-Qing ZHANG ◽  
Li-Li ZHAO ◽  
Shi-Long XU ◽  
Chao ZHANG ◽  
Xiao-Ying CHEN ◽  
...  
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Polyvinylidene Fluoride ◽  
Wide Band ◽  
High Refractive Index ◽  
Wide Band Gap ◽  
Optical Film
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