| 1. |
- Engström, Jonas, 1974, et al.
(författare)
-
Functional beads of polyvinylpyrrolidone: promising support materials for solid-phase synthesis
- 2006
-
Ingår i: Macromolecular Chemistry and Physics. ; 207:6, s. 605-614
-
Tidskriftsartikel (refereegranskat)abstract
- 3-But-3-enyl-1-vinylpyrrolidin-2-one, 3,3-dibut-3-enyl-1-vinylpyrrolidin-2-one, 3-undec-10-enyl-1-vinylpyrrolidin-2-one, and 3,3-diundec-10-enyl-1-vinylpyrrolidin-2-one were prepd. and suspension polymd. to prep. hydrophilic polymer beads. Undec-10-en-1-ol was used as a comonomer for the introduction of functional groups. The lightly crosslinked beads contained hydroxyl groups at functional loading 0.28 mmol/g and swelled extensively in a broad range of solvents. [on SciFinder (R)]
|
|
| 2. |
- Engström, Jonas, 1974, et al.
(författare)
-
Novel densely alkylated hydroxyl-functional polyvinylpyrrolidone showing phase-selective solubility
- 2006
-
Ingår i: Macromolecular Chemistry and Physics. ; 207:12, s. 1062-1069
-
Tidskriftsartikel (refereegranskat)abstract
- Polyvinylpyrrolidone (PVP) is a commonly used polymer with many different applications in the pharmaceutical, cosmetic and food industries. However, the lack of reactive groups and the difficulty in copolymg. the monomer, N-vinylpyrrolidin-2-one (NVP) with most other monomers, limits the possibility of modifying the phys. and chem. properties of the polymer. Monomers that are derivs. of NVP itself are expected to show small differences in radical reactivity as compared to the parent monomer and provide a way of adjusting the polymer properties without extensive compositional drift during copolymn. Here we present the synthesis of two new functionalized NVP-based monomers and their copolymn. with alkylated NVP-monomers for the prepn. of two functionalized PVPs with phase-selective soly. in heptane. Both copolymers showed 99.99% selective soly. in heptane over DMF (thermomorphic system) and 99.99% in heptane over 90% EtOH-H2O (latent biphasic system). These results suggest that the polymers could be used as sol. supports to facilitate recovery and recycling of catalysts or reagents from liq./liq. systems after homogeneous reactions. [on SciFinder (R)]
|
|
| 3. |
- Engström, Jonas, 1974, et al.
(författare)
-
Synthesis of novel monomers and copolymers from 1-vinylpyrrolidin-2-one: attractive materials for drug delivery systems?
- 2006
-
Ingår i: Macromolecular Chemistry and Physics. ; 207:5, s. 536-544
-
Tidskriftsartikel (refereegranskat)abstract
- Polyvinylpyrrolidone (PVP) is a synthetic, non-toxic, water-sol. polymer commonly used in a wide range of applications including several pharmaceutical applications. One example of an important application is the controlled release and delivery of therapeutic agents into sites of inflammation or tumors. However, PVP lacks reactive groups, which limits the possibility of adding new functions to the polymer in order to modify its phys. and chem. properties. Furthermore, large differences in radical reactivity between 1-vinylpyrrolidin-2-one (NVP) and most other monomers lead to compositional drift during copolymn. This complicates the introduction of reactive groups into the polymer using this method. Monomers that are derivs. of NVP itself are expected to show smaller differences in radical reactivity and therefore provide a way of prepg. PVP with adjustable properties. Here we present the synthesis of five NVP-based monomers and their use in the prepn. of functional PVP with adjustable properties in terms of soly., loading of functional groups, and molar mass. The results show the possibility of tailoring PVP for different biomedical applications e.g. drug delivery systems. [on SciFinder (R)]
|
|
| 4. |
- Helgee, Bertil, 1947, et al.
(författare)
-
A liquid crystal device and a method for manufacturing thereof
- 2005
-
Patent (övrigt vetenskapligt/konstnärligt)abstract
- The invention relates to a liq. crystal device comprising a liq. crystal bulk layer and a dynamic surface-director alignment layer, wherein the liq. crystal bulk layer comprises a liq. cryst. material possessing a phase sequence consisting of isotropic phase, nematic phase and optionally cryst. phase (s), and the surface-director alignment layer comprises a chiral smectic liq. cryst. polysiloxane. The invention also relates to a method for its manufg. [on SciFinder (R)]74 FIELD Section Title:Radiation Chemistry, Photochemistry, and Photographic and Other Reprographic ProcessesField url:Ae, ag, al, am, at, au, az, ba, bb, bg, br, bw, by, bz, ca, ch, cn, co, cr, cu, cz, de, dk, dm, dz, ec, ee, eg, es, fi, gb, gd, ge, gh, gm, hr, hu, id, il, in, is, jp, ke, kg, km, kp, kr, kz, lc, lk, lr, ls, lt, lu, lv, ma, md, mg, mk, mn, mw, mx, mz, na, ng, ni, no, nz, om, pg, ph, pl, pt, ro, ru, sc, sd, se, sg, sk, sl, sm, sy, tj, tm, tn, tr, tt, tz, ua, ug, us, uz, vc, vn, yu, za, zm, zw.At, be, ch, cy, de, dk, es, fi, fr, gb, gr, ie, is, it, lu, mc, nl, pt, se, tr, bf, bj, cf, cg, ci, cm, ga, ml, mr, ne, sn, td, tg.G02f001-1347.G02f001-1337; g02f001-141; c09k019-40.Application: WO20050608.2005-ep6145Ep2004-1359220040609 FIELD Citations:Demus, D; WO 0003288 A 2000|Galli, G; MOLECULAR CRYSTALS AND LIQUID CRYSTALS 2001, 360, 147|Komitov, L; WO 03081326 A 2003|Komitov, L; JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY SOC, 11, 437|Merck Patent Gmbh; WO 8909203 A 1989
|
|
| 5. |
- Komitov, Lachezar, 1944, et al.
(författare)
-
Controllable alignment of nematics by nanostructured polymeric layers
- 2009
-
Ingår i: Liquid Crystals. - 1366-5855 .- 0267-8292. ; 36:6 & 7, s. 747-753
-
Tidskriftsartikel (refereegranskat)abstract
- A method for a continuous control of the pretilt angle of the easy axis in the range 0-90° degrees and of the anchoring strength by using nanostructured polymers as alignment layers is described. The nanostructured polymers are blends of two different side-chain polymers each of them promoting planar and homeotropic alignment, respectively. A model to interpret the alignment of a nematic liquid crystal induced by such polymer layers is proposed. We show that in this case the anisotropic part of the surface tension can be approximated by a simple extension of the Rapini-Papoular expression. The predicted trend of the pretilt of the easy axis versus the concentration of the side-chain polymer promoting the planar alignment, for instance, is in good agreement with the experimental data. We also show that the effective anchoring strength of the system depends on the concentration of the side-chain polymer promoting planar alignment, and exhibits a minimum for a well-defined value of this quantity. The results obtained in this work seems to be of importance for liquid crystal displays technology since the control of the pretilt and the anchoring strength strongly affect the performance of liquid crystal displays.
|
|
| 6. |
- Komitov, Lachezar, 1944, et al.
(författare)
-
Electrically commanded surfaces for nematic liquid crystal displays
- 2005
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 86
-
Tidskriftsartikel (refereegranskat)abstract
- Electrically commanded surfaces (ECS) is a liquid crystal display concept whereby the switching of the alignment layer, which is driven by an electric field applied across the layer, is further transferred to the bulk liquid crystal material via elastic forces. This work presents the electro-optic response of a sandwich cell with alignment layer made of siloxane-based ferroelectric liquid crystal polymer, representing the ECS. The bulk liquid crystal material of choice was an in-house nematic mixture comprising fluorinated liquid crystalline compounds with negative dielectric anisotropy (Delta-epsilon < 0). We report a distinct linear electro-optic response, arising from the field-induced in-plane switching of the nematic which in turn is mediated by the ECS. © 2005 American Institute of Physics. [DOI: 10.1063/1.1849844]
|
|
| 7. |
- Komitov, Lachezar, 1944, et al.
(författare)
-
Liquid crystal device and method its fabrication
- 2004
-
Patent (övrigt vetenskapligt/konstnärligt)abstract
- The invention relates to a liq. crystal device comprising a liq. crystal bulk layer and a surface-director alignment layer comprising side-chains arranged to interact with the bulk layer, wherein the orientation of the bulk layer mols. and the orientation of said side-chains each is directly controllable by an elec. field via dielec. coupling, thus resulting in a decreased total time period (rise and decay times) needed to switch and relax the liq. crystal bulk mols. in response to an applied external field. The invention also relates to a method for manufg. a liq. crystal device and a method of controlling a liq. crystal bulk layer.
|
|
| 8. |
- Komitov, Lachezar, et al.
(författare)
-
Liquid crystal device and method its fabrication
- 2004
-
Patent (övrigt vetenskapligt/konstnärligt)abstract
- The invention relates to a liq. crystal device comprising a liq. crystal bulk layer and a surface-director alignment layer comprising side-chains arranged to interact with the bulk layer, wherein the orientation of the bulk layer mols. and the orientation of said side-chains each is directly controllable by an elec. field via dielec. coupling, thus resulting in a decreased total time period (rise and decay times) needed to switch and relax the liq. crystal bulk mols. in response to an applied external field. The invention also relates to a method for manufg. a liq. crystal device and a method of controlling a liq. crystal bulk layer. [on SciFinder (R)]Notes:Can 142:8251974-13 FIELD Section Title:Radiation Chemistry, Photochemistry, and Photographic and Other Reprographic ProcessesField url:Ae, ag, al, am, at, au, az, ba, bb, bg, br, bw, by, bz, ca, ch, cn, co, cr, cu, cz, de, dk, dm, dz, ec, ee, eg, es, fi, gb, gd, ge, gh, gm, hr, hu, id, il, in, is, jp, ke, kg, kp, kr, kz, lc, lk, lr, ls, lt, lu, lv, ma, md, mg, mk, mn, mw, mx, mz, na, ni, no, nz, om, pg, ph, pl, pt, ro, ru, sc, sd, se, sg, sk, sl, sy, tj, tm, tn, tr, tt, tz, ua, ug, us, uz, vc, vn, yu, za, zm, zw.At, be, ch, cy, de, dk, es, fi, fr, gb, gr, ie, it, lu, mc, nl, pt, se, tr, bf, bj, cf, cg, ci, cm, ga, ml, mr, ne, sn, td, tg.G02f001-1337.C09k019-02.Application: WO20040607.2004-se880Se2003-181020030623 FIELD Citations:Mazaki, H; US 5578243 A 1996|Sharp Kk; GB 2326245 A 1998|Sharp Laboratories Of Europe Ltd; WO 0123953 A1 2001|Merck Patent Gmbh; EP 1310541 A2 2003Secondary title:PCT Int. Appl.
|
|
| 9. |
- Komitov, Lachezar, 1944, et al.
(författare)
-
Nano-Structured Polymers for Alignment Layers in LCDs
- 2008
-
Ingår i: SID Symposium Digest of Technical Papers. - : Wiley. - 0097-966X. ; 39:1, s. 598-599
-
Tidskriftsartikel (refereegranskat)abstract
- By employing a nano-engineering approach, nano-structered polymers were designed, synthesised and used as materials for alignment layers in LCDs. Such materials make possible to control the molecular tilt angle in a broad range, from 0° to 90°, and they seems to enable the control of the anchoring strength as well.
|
|
| 10. |
- Komitov, Lachezar, 1944, et al.
(författare)
-
Necessary conditions for display and fast switching of high contrast images by antiferroelectric liquid crystal displays
- 2006
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 89
-
Tidskriftsartikel (refereegranskat)abstract
- Antiferroelectric liquid crystals (AFLC) with 45° molecular tilt were stated to be the solution of the dark state problem in AFLC displays (AFLCDs). However, AFLCs that are available at present actually possess antiferroelectric (AF) to ferroelectric (F) transition of first order characterized by slow switching times which in turn deteriorates the dark state in AFLCDs. Here, we report on the switching behavior of a siloxane AFLC dimer with molecular tilt close to 45°. This material exhibits AF to F transition of second order at lower temperatures, something that enables display and fast switching of high contrast images in AFLCDs. ©2006 American Institute of Physics
|
|
