Liquid Crystal Laboratory

Liquid Crystal Laboratory
Liquid Crystalline Physics and Applications
Members    Facilities        Projects         Publications  Graduated Researchers
Liquid crystals (LCs) are important materials for fundamental researches as well they can be used in technological and commercial applications. Since liquid crystalline state (mesophase) exhibits a specific phase between isotropic liquids and 3-d solid crystals, the investigation of physical properties of LCs is rather complex and therefore requires the using of various devices and techniques. LCs play an important role in scientific researches in many different fields such as solid state physics, soft matter physics, organic chemistry etc. In solid state physics and soft matter physics; under any physical fields, variation of physical properties of LCs is investigated by doping nano-dimensional organic and inorganic several materials. In addition to this, LCs are standard material in organic chemistry in order to investigating relation between chemical structure and physical properties. Besides, information about some phenomenon of biological systems can be obtained by using LCs. Since their fundamental application field is displays, some principle properties of LCs should be acquired in order to understand details about display technology.
LCs play an important role in modern life. In daily life, LCs are significantly used in watches, displays of computers and televisions, cell phones, hand calculators, cameras and so on technological applications. Moreover, LCs are also used in temperature sensors, spatial light modulators, lasers, slide projectors etc., and play a part in improving of them. The main reason for having an important role in related applications is that LCs change their form (state) by being used very low energies under external fields such as thermal, electric, mechanical stress. Furthermore, liquid crystals constitute a very important point of view for biological applications.
In Liquid Crystals Research Laboratory which is founded at Department of Physics, investigations of the physical and physical-chemical properties of LCs and also researches on applications of  these materials are carried out. Relevant studies are summarized as follows:
  • Phase Transition analogy between Smectic A-Nematic and Metal-Superconductor
  • Electrical and optical properties of Bend-Core molecular shaped liquid crystals
  • Gas Sensors based on Cholesteric and Blue Phase liquid crystals
  • PDLC (Polymer Dispersed Liquid Crystals) liquid crystals which are used in smart window technology
  • Liquid crystal fibers which are used in wearable products and light modulators
  • Thermo-optical, electro-optical and magneto-optical properties of thermotropic liquid crystals
  • Phase states of Lyotropic liquid crystals; binary, triadic and quadruple phase diagrams of them
  • Mesomorphical, morphological, thermotropical, orientational and optical properties of Lyotropic liquid crystal mesophases
  • Thermodynamic, thermo-optical, magneto-optical, magneto-morphological and electro­physical peculiarities of Lyotropic liquid crystals
 
Members
Prof. Dr. Arif Nesrullajev (Nesrullazade)
https://scholar.google.com.tr/citations?hl=tr&user=ZeAJOfkAAAAJ
narifn.2018@gmail.com

 
Assoc. Prof. Dr. Nejmettin AVCI    
navci@mu.edu.tr
(252)211-15-90
http://www.mu.edu.tr/tr/personel/navci
https://scholar.google.com.tr/citations?user=ftU_iEIAAAAJ&hl=en
           
 
Dr. Pınar ÖZDEN 
pozden@mu.edu.tr
(252)211-16-04
https://www.researchgate.net/profile/Pinar_Ozden
http://www.mu.edu.tr/tr/personel/pozden
           
Dr. Atilla Eren MAMUK
aemamuk@mu.edu.tr
(252)211-5107
http://www.mu.edu.tr/tr/personel/aemamuk
http://akademik.mu.edu.tr/aemamuk
https://scholar.google.com.tr/citations?user=ruU56qsAAAAJ&hl=tr
https://www.researchgate.net/profile/Atilla_Mamuk


 
Facilities
Polarized Optical Microscopy (POM) Setup
Polarized Optical Microscopy (POM) Setup is used for investigation of crystallographical, mesomorphical, optical and orientational properties of LCs.  POM system is composed of “Olympus” trinocular polarized microscope, “Olympus” and “Canon 6D” microphotographic systems connected to microscope, “Olympus” Berek compensator and two different λ-planes (λ1=0.137μm and λ2=0.530μm). A thermostat heater, “Good Will GPS 3003” 36V DC power supplier, “Leybold” digital temperature controller, “Keithley 2000 and 2010” multimeters and Cu-Co differential thermo-couples are used for temperature dependent measurements. POM Setup is utilized as a prevalent method so as to identify liquid crystalline mesophases and investigate various structural properties. This method is based on composing of textures depended on molecular order and position in liquid crystalline mesophases (Demus ve Richter, 1978; Sonin, 1983; De Gennes ve Prost, 1993; Dierking, 2003). System components are given as follows:
  • Olympus BX-51P Trinocular Optical Polarized Microscope
  • Canon EOS 6D Digital  Photographic Apparatus
  • Olympus SC-35 Micro-Photographic Apparatus
  • Olympus U-CTB Berek Compensator
  • Olympus U-TP137 and U-TP530 wave planes
  • Olympus U-TAD Object-micrometer


UV-VIS Optical Measurement Setup
Optical transmission, reflection and absorption properties of liquid crystal cells are investigated in the range of 300-1100 nm wave lengths by means of this setup. Also, thickness of the cells that liquid crystals are injected is precisely determined with utilizing system. By this way, selective reflection peaks are specified in spectrum range from UV region to IR region. System components are given as follows:
  • Ocean Optics DH-2000-BAL Tungsten Source
  • Ocean Optics FLAME-S-XR1 Light Detector
  • UVGL-58 UV Light Source


Electrical Measurements Setup
Splay, bend and twist Frank elastic constants of liquid crystals have and important role on characterization of liquid crystal displays, especially in terms of imaging speed and power distribution. Elastic constants of liquid crystal are obtained by measuring threshold voltage during Fredericsz transition. In addition to this, a specific method based on Fredericsz transition is utilizing in order to determining of viscosity constant. Hence, electrical measurements setup which is founded in our laboratory is used for finding elastic constants out and specifying viscosity constant. System components are given as follows:
  • Tektronix AF3021C Signal Generator
  • FLC F20A Voltage Amplifier
  • Tektronix TBS 1102B EDU Digital Oscilloscope


Abbe Refractometry Setup
Temperature dependent refractive indices and birefringence values of LCs are measured by using Abbe Refractometry Setup. This system makes it possible to obtain refractive index values of LCs with an accuracy of ±10-4. Besides, this system has an “Atago” digital temperature controller and a “Selecta” silicone bath chiller. Thus, measurement temperature of material which is measured can be varied with an accuracy of ±0.1K. Both polychromatic and monochromatic light sources can be used for refractive index measurement. System components are given as follows:
  • Atago Abbe Refractometry
  • Atago Digital Temperature Controller
  • Selecta Silicone Bath Chiller

Polythermic Electrical Conductivity Setup
Temperature and Concentration dependence of electrical conductivity of lyotropic LCs is examined by utilizing this system. Temperature of sample which is settled into a tube is changed by a heater which is within a water bath. Also, conductivity of the sample is determined by a pin. System components are given as follows:
  • WiseCircu Fuzzu Circulating Water Thermostat
  • YSI3200 Electroconductivity Instrument

Other Setups and Utility Devices
  • Selecta Ultrasonic Bath
  • Velp Scientifica Vortex Stirrer
  • Keithley Multimeters
  • Shimadzu Assay Balance
  • Pasco Variable Gap Magnet
  • Leybold Digital Temperature Controller
  • Brymen Practical Digital Multimeters
  • Selecta Thermostat-Drying Chamber
  • Insek Laboratory DC Power Suppliers
  • Uniphase 155SL and Industrial Fiber Optics Hard Seal Lasers
  • Sypris F.W.Bell Gauss/Teslameter
 
Projects
  • Using of cholesteric liquid crystals with selective transmittance as glass coating and investigating of effect of thermal - electrical energy saving on Mugla province. Advisor: Nejmettin Avcı. Researchers: Pınar Özden, Şadan Özden, Atilla Eren Mamuk. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2017 - Continued.
  • Investigation of optical and thermo-optical properties of smectogen and nematogen thermotropic liquid crystals. Advisor: Arif Nesrullazade. Researchers: Atilla Eren Mamuk. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2016-2019.
  • Investigation of thermotropic, optical refractivity and optical birefringence peculiarities of liquid crystalline materials in wide temperature range. Advisor: Nejmettin Avcı. Researchers: Pınar Özden, Arif Nesrullazade, Atilla Eren Mamuk. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2015 - 2017.
  • Investigation of thermo-morphological, thermotropic, thermo-optic and dielectric properties of finite dimensinol micelized lyotropic liquid crystalline mesophases. Advisor: Arif Nesrullazade. Researchers: Pınar Özden. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2015-2017.
  • Studying of morphological, structural, thermotropic and optical properties of defective textures and defective formations in liquid crystals. Advisor: Arif Nesrullazade. Researchers: Pınar Özden, Atilla Eren Mamuk. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2015 - 2018.
  • Studying of thermo-morphological, thermotropic, thermo-optical and thermodynamical properties of multi-phase transition liquid crystals. Advisor: Arif Nesrullazade. Researchers: Belkıs Eran Bilgin, Ferit Salehli, Pınar Özden, Nejmettin Avcı. Supporter: Muğla Sıtkı Koçman University Scientific Research Project Office. 2009 - 2011.
Publications
Articles Published in Journals Indexed in SCI or SCI Expanded, SSCI, AHCI
2019
Özden Pınar, Mamuk Atilla Eren, Avcı Nejmettin, 2019. Investigation of the Viscoelastic Properties of 4-propoxy-biphenyl-4-carbonitrile. Lıquıd Crystals
(https://www.researchgate.net/publication/333076913_Investigation_of_the_viscoelastic_properties_of_4-propoxy-biphenyl-4-carbonitrile)
 
2018
Lin Huayang, Avcı Nejmettin, Hwang Shug June, 2018. High Diffraction Efficiency Fresnel Lens Based on Annealed Blue Phase Liquid Crystal-Polymer Composite. Lıquıd Crystals
(https://www.tandfonline.com/doi/full/10.1080/02678292.2018.1562114)
2017
Avcı Nejmettin, 2017. The influence of diluter system on polymer-stabilised blue-phase liquid crystals. Liquid Crystals
(https://www.tandfonline.com/doi/full/10.1080/02678292.2017.1346825)
Mamuk Atilla Eren, Nesrullazade Arif, Mukherjee Prabır K, 2017. Refractive and birefringent properties of4-alkyl-4'-oxycyanobiphenyls at direct and reverse phasetransitions. Molecular Crystals And Lıquıd Crystals
(https://www.researchgate.net/publication/308902311_Refractive_and_Birefringent_Properties_of_4-Alkyl-4'-Oxycyanobiphenyls_at_Direct_and_Reverse_Phase_Transitions)
Avcı Nejmettin, Hwang Shug June, 2017. Electrically tunable polarisation-independent blue-phase liquid crystal binary phase grating via phase-separated composite films. Liquid Crystals
(https://www.tandfonline.com/doi/full/10.1080/02678292.2017.1303094)
2016
Nesrullazade Arif, Özden Pınar, 2016. Investigation of Phase States Thermo Morphologic Magneto Morphologic and Refractive Properties of Mesophases in Dodecyltrimethyl Ammonium Bromide Water Lyotropic Liquid Crystalline System. Tenside Surfactants Detergents
Mamuk Atilla Eren, Nesrullazade Arif, 2016. Refractive and birefringent properties and orderparameter of nematic liquid crystal at the direct andreverse nematic isotropic liquid phase transition. Journal Of Optoelectronics And Advanced Materials
(https://www.researchgate.net/publication/311486518_Refractive_and_birefringent_properties_and_order_parameter_of_nematic_liquid_crystal_at_the_direct_and_reverse_nematic_isotropic_liquid_phase_transition)
Avci.,N., Han .,Y., June, 2016. Switchable polarisation-independent blue phase liquid crystal Fresnel lens based on phase-separated composite films. Liquid Crystals
(https://www.tandfonline.com/doi/full/10.1080/02678292.2016.1262070)
2015
Özden Pınar, Nesrullazade Arif, 2015. Comparative investigations of the thermotropic and optical refractive properties in micellar isotropic phase and nematic calamitic mesophase of hexadecyltrimethyl ammonium bromide water and hexadecyltrimethyl ammonium bromide water 1 decanol lyotropic liquid crystalline systems. Colloid and Polymer Science
2013
Avcı N. , Borshch V.,  Sarkar D. D., Deb R., Venkatesh G.,  Turiv T.,  Shiyanovskii S. V., Rao N. V. S. ve Lavrentovich O. D. Viscoelasticity, dielectric anisotropy, and birefringence in the nematic phase of three four-ring bent-core liquid crystals with an L-shaped molecular frame, Soft Matter, 9: 1066-1075, 2013.
2012
A.Nesrullajev, Ç.Yörür-Göreci, B.Bilgin-Eran, “Thermotropic, Thermo-morphologic and Thermo-optical Properties of New Smectogenic Calamitic Compounds Containing Imine Linking Groups”, “International Journal of Thermophysics”, v.33, pp.58-68, 2012.
Avci.,N., Borshch.,V., Sarkar.,D., Deb.,R., Venkatesh.,G., Turiv.,T., Shiyanovskii.,V., Rao.,S., Lavrentovich.,D., 2012. Viscoelasticity, dielectric anisotropy, and birefringence in the nematic phase of three four-ring bent-core liquid crystals with an L-shaped molecular frame. Soft Matter
2011
N.Yılmaz-Canli, B.Bilgin-Eran, A.Nesrullajev, “Synthesis, Mesomorphic and Physical Properties of Two New Analogs of Schiff’s Base with an Alkenic Terminal Chains” – “Journal of Molecular Structure”, v.990, pp.79-85, 2011.
A.Nesrullajev, N.Avcı, “Oriented and Non-Oriented Textures of Nematic Liquid Crystals: Comparative Peculiarities of the Thermotropic Behaviour”, “Materials Chemistry and Physics”, v. 131, pp. 455-461, 2011.
2010
A.Nesrullajev, “Sizes and Anisometricity of Micelles in Lyotropic Liquid Crystalline Mesophases: Sodium Lauryl Sulphate / Water / Decanol Lyotropic System” – “Tenside, Surfactants, Detergents”, v.47, No.3, pp.178-183, 2010.
A.Nesrullajev, “Changes of Thermo-Morphologic and Thermotropic Properties of Nematic Mesophase ↔ Isotropic Liquid Phase Transition: Surface-Induced Effect” – “Phase Transitions”, v.83, No.5, pp.326-337, 2010.
N.Avcı, A.Nesrullajev, Ş.Oktik, “Nonlinear thermotropic and thermo-optical behaviour of planar oriented textures in nematic liquid crystals at phase transitions” – “Brazilian Journal of Physics”, v.40, No.2, pp.224-227, 2010.
A.Nesrullajev, “Shape and Sizes of Micelles in Nematic-Calamitic and Nematic-Discotic Mesophases: Sodium Lauryl Sulphate / Water / Decanol Lyotropic System” – “Materials Chemistry and Physics”, v.123, pp.546-550, 2010.
N.Avcı, A.Nesrullajev, Ş.Oktik, “Thermotropic and thermo-optical properties of nematic mesophase at direct and reverse phase transitions” – “International Journal of Thermophysics”, v.31, pp.2216-2224, 2010.
P.Özden, A.Nesrullajev, Ş.Oktik, “Phase States and Thermo-Morphologic, Thermotropic and Magneto-Morphologic Properties of Lyotropic Mesophases: Sodium Lauryl Sulphate/Water/1-Decanol Liquid Crystalline System” – “Physical Review E”, v.82, pp.061701-1 - 061701-8, 2010.
2009
A.Nesrullajev, “Peculiarities of inversion walls and singular points in oriented textures of nematic mesophase”, “Crystal Research and Technology”, v.44, p.747-753, 2009.
N.Yılmaz Canlı, A.Nesrullajev, Ö.Yasa, B.Bilgin Eran, “Synthesis, Characterization and Thermal Behaviour of New Chiral Imine Mesogens and Their Achiral Analogs”, “Journal of Optoelectronics and Advanced Materials – Symposia”, v.1, pp.577-581, 2009.
2008
A.Nesrullajev, B.Bilgin Eran, Ç.Yörür, “4-(Octyloxy)-n-(4-hexylphenyl)-2-hydrobenzalimine thermotropic compound: Morphologic, mesomorphic, thermotropic, thermooptical and thermodynamical properties”, “International Journal of Modern Physics B”, v.22, pp.281-291, 2008.
A.Nesrullajev, B.Bilgin Eran, “Thermo-Morphological Properties of the Smectic C* Mesophase in New Chiral Salicyaldimine Liquid Crystals”  – “Crystal Research and Technology”, v.43, pp.308-313, 2008.
N.Avcı, A.Nesrullajev, Ş.Oktik, “Peculiarities of Thermotropic Behaviour of Homeotropic and Schlieren Textures in Monomorphic Mesogen” – “Balkan Physics Letters”, ISSN 1301-8329, pp.313-316, 2008.
B.Bilgin Eran, A.Nesrullajev, N.Canlı Yılmaz “Characterization and Investigation of the Mesogenic, Morphologic and Thermotropic Properties of New Chiral (S)-5-Octyloxy-2-[{4-(2-Methylbuthoxy)-Phenylimino}-Methyl]-Phenol Liquid Crystalline Compound” – “Materials Chemistry and Physics”, v.111, pp.555-558, 2008.
2007
A.Nesrullajev, Ş.Oktik, “Texture Transformations and Orientational Properties of Lyotropic Nematics in Magnetic Field”,  “Crystal Research and Technology”, v.42 pp. 44 – 49, 2007.
S.Yıldız, A.Nesrullajev, “Change of Thermotropic Properties in Liquid Crystal with Multiple Phase Transitions: Surface “Aging” Effect”, “Physica A”, v.385, pp.25-34, 2007.
N.Avcı, A.Nesrullajev, Ş.Oktik, “Peculiarities of Light Transmission by Nematic – Isotropic Liquid and Isotropic Liquid – Nematic Phase Transitions” – “Journal of Optoelectronics and Advanced Materials”, v.9, pp.413-416, 2007
A.Nesrullajev, N.Avcı, Ş.Oktik, “Peculiarities of Biphasic Regions at Phase Transitions in Oriented Textures of 4-Cyano-4’-N-Pentylbiphenyl” – “Physics Letters A”, v.364, pp.510-514, 2007.
Ç.Yorur, A.Nesrullajev, B.Bilgin Eran “New Imine Compounds and Their Copper Complexes: Synthesis, Characterization and Comparative Investigations of Morphologic, Mesomorphic, Thermotropic, Thermooptical and Thermodynamical Properties” –  “Molecular Physics”, v.105, pp.2961-2970, 2007.
2006
A.Nesrullajev, Ş.Oktik, “Induced changes of smectic A – isotropic liquid phase transition peculiarities: Effect of surfaces”, “Modern Physics Letters B”, v.20, pp.821-833, 2006.
A.Nesrullajev, B.Bilgin Eran, “N-Salicylidene anilines and their copper complexes: Comparative investigations of mesomorphic, morphologic, thermotropic and thermodynamical properties”, “Molecular Physics”, v.104, pp.1371-1383, 2006.
Ö.Polat, A.Nesrullajev, Ş.Oktik, “Effect of Thickness of Liquid Crystalline Layer on the Thermotropic and Thermodynamical Properties of Nematic – Isotropic Liquid and Izotropic Liquid – Nematic Phase transitions”, “International Journal of Modern Physics B”, v.20, pp.3383-3394, 2006.
2005
A.Nesrullajev, F.Z.Tepehan, “Effect of the Surfaces on Orientational Properties and Peculiarities of Phase Transitions in Thermotropic Nematics” konulu makale “International Journal of Modern Physics B” , v.19, No.18, pp.2975-2987, 2005.
A.Nesrullajev, B.Bilgin Eran, “Mesomorphic, morphologic and thermoptropic properties of 4-Hexyl-N-(4-hexadecyloxysalicilidene)aniline”, “Materials Chemistry and Physics”, v.93, pp.21-25, 2005.
Books
A.Nesrullazade (Nesrullajev), “Liyotropic Liquid Crystals. Amphiphilic Systems”, Muğla University Press, Muğla, ISBN 978-975-7207-85-6,  2007.
 A.Nesrullazade, “Geometrik Optiğin Temelleri, Fotometri, Optiksel Sistemler ve Optiksel Cihazlar. Problemler ve Çözümleri”, DORA Basım-Yayın Dağıtım Ltd. Sti., Bursa, ISBN: 978-605-4485-79-6, 2012.
Researchers Graduated from Liquid Crystalline Physics and Applications Research Laboratory
  • Ömer Polat. MSc Thesis, Investigation of nematic-isotropic liquid and isotropic liquid-nematic phase transitions in thermotropic liquid crystals, Mugla University, 2005.
  • Nejmettin Avcı, MSc Thesis, Investigation of thermo-optical, thermo-morphological and thermotropic properties of nematic-isotropic liquid and isotropic liquid-nematic phase transitions, Mugla University, 2007.
  • Pınar Özden, MSc Thesis, Studying of phase states, thermo-morphological, thermotropic and magneto-morphological properties of sodium lauryl sulphate based lyotropic liquid crystalline systems, Mugla University, 2013.
  • Nejmettin Avcı, PhD thesis, Studying of Mesomorphic, thermo-morphological and thermo-optical properties of Multi-phase transition liquid crystals, Mugla University, 2013.
  • Çınar Özden, MSc thesis, Thermotropic cholesteric liquid crystals: investigation of mesomorphic, thermo-morphological and thermo-optical properties, Mugla University, 2013.
  • Pınar Özden, MSc Thesis, Investigation of thermo-morphological, thermotropic, thermo-optic and dielectric properties of finite dimensinol micelized lyotropic liquid crystalline mesophases, Mugla University, 2017.
  • Atilla Eren Mamuk, PhD thesis, Investigation of optical and thermo-optical properties of smectogen and nematogen thermotropic liquid crystals, Mugla University, 2019.