Site: Niopik Organic Intermediates and
Dyes Institute
Sadovaya, 1-4,
Moscow 103787
Russia

Date Visited: October 29, 1993

Report Author: P.E. Cladis

ATTENDEES

WTEC:

P.E. Cladis
J.W. Doane

HOSTS:

Dr. Ruben Geivandov

Professor V.G. Chigrinov

SUMMARY

The major strength of the Organic Intermediates and Dyes Institute is its expertise in the research, development, and large-scale production of organic materials for the electronics industries. Indeed, it is probably the only commercial source for these materials in Russia. Niopik has the capability to synthesize large volumes of liquid crystal materials and characterize their electro-optic response to satisfy particular customer demands. It also supplies materials for alignment layers, polarizers, retardation filters, and color filters, and has a no-rubbing LC technology using photosensitive polymers on a glass/ITO substrate. While Niopik has a legal office for Russian patents, foreign patents require interactions with outside companies, primarily for funding.

BACKGROUND

Niopik is a state enterprise that has been recently opened to foreigners. The WTEC team's hosts mentioned that the team was about the third non-FSU visitor following Martin Schadt (Hoffman- LaRoche, Switzerland) and Georges Durand (University of Paris- South, France). While Dainippon Ink has licensed some of its technology, there have so far been no visitors from Japan. Niopik is state supported at about 30% of its previous level. In the chemical sector, there are four such enterprises in Russia.

The main business of the Niopik Organic Intermediate and Dyes Institute is the development and production of organic materials for the electronics industry (e.g., liquid crystals and photoresists) as well as for academic research. Dr. Ruben Geivandov told the visiting WTEC team that Niopik's three main directions are: (1) the technology of organic dyes; (2) technology of semiproducts (intermediates) for the textile industry; and (3) materials for new technologies. Some of the materials the institute was producing and characterizing were low molecular weight liquid crystal materials; wet and dry photoresists for microelectronics; materials for laser technology and chemical dosimetry (sensors); electrochromic materials (reversible chemical reactions) for a window application (slow); and fast photochromic materials (light-induced shift in absorption wavelength).

Niopik now has ten patents with Hoffman-LaRoche as well as a cooperation with Merck, Darmstadt, and Dainippon Ink. Niopik has a legal group so that patents are filed in Russia as well as outside Russia. The cost for patents outside the FSU (e.g., for some pyridine derivatives described as having good solubility and dielectric constants) were financed by the non-Russian companies (e.g., Hoffman-LaRoche in Europe and Dainippon Ink in Japan). The institute has about 50 liquid crystal mixtures for industry (100 kg or more at about $1.50-2.00/g) and 200 materials on a laboratory scale for research.

Research collaborations are either in place or are being developed with academic colleagues in both Russia (e.g., Professors Pikin and Blinov at the Crystallographic Institute) and Europe (e.g., Professors L. Kramer, Bayreuth, and A. Strigazzi, Torino). In September 1993, the European community announced the availability of funding for collaboration between FSU scientists and scientists from at least two European countries. Also, the team was told that there is a Russian Liquid Crystal Society whose current Chairman is Dr. Viktor Titov. Dr. Titov, formerly of the Organic and Intermediates and Dyes Institute, is now Director of the Polygraphic Institute.

RESEARCH AND DEVELOPMENT ACTIVITIES

Dr. Sergey V. Belyaev showed the team a few of the many techniques employed to characterize nematic liquid crystal materials in both the TN (twisted nematic, 10 micron thick cell) and "pi"-cell (6-7 micron thick) geometry. The catalogue presented to the team shows that the institute also has the capability of characterizing the electro-optics of ferroelectric liquid crystal materials, PDLC films, and electrochromic materials, as well as the optical characteristics of linear polarizers and retardation films that Niopik also produces. Indeed, the institute has found that its polarizers are as good as those of Nitto Denko. Niopik's current polarizer production is 1,000 square meters/year, which will increase to 10,000 square meters next year. The institute has a cooperation with both Platan and Saratov for polarizers and both uniaxial and biaxial retardation films. Niopik's cooperation with Ukraine and Belarus is now difficult because they are now different countries with different currencies.

Dr. Belyaev also demonstrated cholesteric mirrors: cholesteric material with pitch between 470-700 nm (i.e., colorful) between relatively thick glass substrates, with the director parallel to one of the substrates and perpendicular to the other. When viewed from one side (the side where the director is in the substrate) a reflected image is clearly seen more or less in the plane of the substrate. Focusing behind the substrate, the view through the substrate could also be clearly seen. While there were red, green, yellow, and blue mirrors, the green one seemed to make the separation between the two images most distinctly with the largest viewing angle. The materials used here were cholesteric from -10þC to 100þC. The mirrors were about 3- 4" on a side. The scientists said that they also have a white mirror that involves four layers of liquid crystals reflecting in a range from 400-700 nm. This activity is a joint venture with Hoffmann-LaRoche.

Finally, Dr. Belyaev showed a PDLC (50/50 LC/polymer) dried down to a 60 micron- thick film between glass substrates. The dielectric anisotropy was about 15, and at 15-20 V, the PDLC became transparent, revealing a colorful picture behind the glass that was completely hidden by the strongly scattering off-state. The viewing angle was good in the transparent state. In the appendix, the Belyaev group reported that the shutter response times were now down to 1 ms, and cell sizes were 30 cm x 30 cm and larger. Transmission was 1% in the off-state and up to 80% in the on-state. The Belyaev scientists also have made these shutters (based on copolymers of polyvinyl alcohol and related materials) on polymer substrates, and reported that they are UV and IR stable with 10,000 working hours without damage.

Dr. Vladimir I. Gavrilov demonstrated organic electrochromic light attenuators and shutters. He said that these materials could attenuate light by as much as 10⁴ to 10⁶. At 1.5 V, the attenuation is about 103 and the response time is 1.8 s, while at 10⁶, it is about 5-6 s. The electrochromic layer is about 150 microns with 2.5 ohms/sq. resistance. These layers could be used for automotive applications (e.g., car mirrors). They can also be used as smart windows. The attenuators had a lifetime of about a million applications of the electric field.

Dr. V.P. Vorflusev showed the team a ferroelectric liquid crystal material aligned with photoinduced alignment layer technology (no rubbing). In this technique, an azo dye is spin-coated onto a glass substrate, then irradiated with linearly polarized UV light. The unusual feature of this geometry (DHF mode) was that the helix of the ferroelectric liquid crystal was very short (0.1 microns) compared to sample thickness, yet its electro-optic response was bistable, contrary to expectations. While bistability disappeared in about 60 ms in rubbed cells and the book-shelf structure was only monostable, samples made with the photo-induced orientation layer were bistable in DHF cells. The contrast between the two electro-optic states looked good in the microscope. Dr. Vorflusev reported that ferroelectrics in the DHF mode made fast light shutters (at 10 V/micron in 1.5 micron thick cells, the response time was about 10 microseconds). Platan is developing a 64 mm x 48 mm DHF light shutter.

Dr. V.M. Kozenkov showed the team his work on photosensitive organic films. Again, UV light is used to induce anisotropy in polymer materials, photoresist materials, polymers doped with dyes and pure dye films as thin as 200 angstroms. Dr. Kozenkov used a (large) Hg lamp (250 W) and 350 nm unpolarized light. Light went through a linear polarizer then onto the organic film to induce anisotropy. He also showed a phase picture with gray scale, made by shining polarized light through a negative film that rotated the plane of polarization by an amount that depended on its transmission through the film. When viewed between crossed polarizers, the original picture was reconstructed. Combined with a template, this technique can be used to make optical gratings when viewed between crossed polarizers.

Dr. P.P. Kisilitsa demonstrated some spectacular colors in organic photochromic/thermochromic materials. After radiation with UV light, the photoinduced color persists from several seconds up to dozens of hours. This technology is applicable to photosensitive glasses. Thermochrome materials show a reversible change of colors when heated within the range of 30-150 degrees centigrade. The change of colors lasts from a fraction of a second to several seconds. The number of thermochrome cycles exceeds 5,000. Applications include temperature sensors.

Finally, Professor Chigrinov gave a brief demonstration of software being developed in collaboration with a group at Saratov. This window package (at a cost between $2-10,000), running on an 80386 microprocessor with DOS operating system, gives results comparable to Becker's (Karlsruhe). The software enables optimization of the output characteristics of LCDs, such as black-and-white and color contrast, viewing angles, response times, and multiplexing capability for various LC physical parameters, display configurations, and driving modes. A wide range of electro-optical effects in LCs are involved, including ECB, twist, supertwist, and quest-host.

REFERENCES

Belayev, S.V., M. Schadt, M.I. Barnik, J. Funfschilling, N.V. Malimoneko, and K. Schmitt. 1990. Jpn. J. Appl. Phys. 29:L634.

Chigrinov, V.G., and G.E. Neskaya. 1991. Mol. Cryst. Liq. Cryst. 209:9.

Schadt, M.K., Schmitt, V. Kozinkov, and V. Chigrinov. 1992. Jpn. J. Appl. Phys. 31:2155.

Tsoy, V.I., G.V. Simonenko, and V.G. Chigrinov. 1993. Liq. Crystals. 13:227.

Vaksman, V.M., and Yu. Panarin. 1992. Mols. Mats. 1:147.

Vorflusev, V.P., V.G. Chigrinov, and Yu. P. Panarin. 1993. Mol. Mat. 2:275.

Yakovlev, D.A., G.V. Simonenko, V.M. Kozinkov, V.G. Chigrinov, and M. Schadt. "New Concept to Achieve In-Situ Color Filters in STN-LCDs with Linearly Photopolymerized (LPP) Substrates." Prepublication.