Liquid-crystalline nanoarchitectures for tissue engineering

• Baeckkyoung Sung and
• Min-Ho Kim

Beilstein J. Nanotechnol. 2018, 9, 205–215, doi:10.3762/bjnano.9.22

• challenges for applying LC nanoarchitectures in tissue engineering fields is discussed. Keywords: biocolloid; biopolymer; cell-matrix interaction; mesophase; regenerative medicine; Review Introduction Liquid crystals (LCs) are ubiquitous in our life [1]. On one hand, LC materials play a central role in

Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes

• Doina Manaila Maximean,
• Viorel Cîrcu and
• Constantin Paul Ganea

Beilstein J. Nanotechnol. 2018, 9, 164–174, doi:10.3762/bjnano.9.19

• low frequencies confirm the presence of EP. Keywords: activation energy; carbon nanotubes; dielectric spectroscopy; ionic liquid crystal; relaxation time; Introduction Ionic liquid crystals (ILCs) represent a very appealing class of materials that has found various recent applications in dye

• dielectric behavior of the bisimidazolium salt. This investigation will be extended to new ionic liquid crystals with a large range of doping concentration in order to complete the existing image on these aspects. Special attention will be paid to low-frequency studies of the effects related to very low CNT

Electrical properties of a liquid crystal dispersed in an electrospun cellulose acetate network

• Doina Manaila Maximean,
• Octavian Danila,
• Pedro L. Almeida and
• Constantin Paul Ganea

Beilstein J. Nanotechnol. 2018, 9, 155–163, doi:10.3762/bjnano.9.18

• in a similar fashion as PDLCs (polymer-dispersed liquid crystals), produced from cellulose acetate (CA) electrospun fibers deposited onto indium tin oxide coated glass and a nematic liquid crystal (E7), were studied. CA and the CA/liquid crystal composite were characterized by multiple investigation

• spectroscopy; liquid crystal; optical transmission; Introduction The widely known polymer dispersed-liquid crystals (PDLCs) are a class of liquid crystal (LC)-based electro-optical devices, formed by LC droplets dispersed in a solid polymeric matrix [1][2][3][4][5]. The optical transmission of such devices is

• investigations of the electrical properties of an electrospun CA network with dispersed liquid crystals. Dielectric spectroscopy (DS) was performed over wide ranges of frequency and temperature to determine physical properties such as activation energy and characteristic time. The experimental results of DS were

Nematic topological defects positionally controlled by geometry and external fields

• Pavlo Kurioz,
• Marko Kralj,
• Bryce S. Murray,
• Charles Rosenblatt and
• Samo Kralj

Beilstein J. Nanotechnol. 2018, 9, 109–118, doi:10.3762/bjnano.9.13

• functional nanodevices. Keywords: nanoparticles; nematic liquid crystals; topological charge; topological defects; Introduction Topological defects (TDs) [1] represent an interdisciplinary research area [2] that is of high interest for nearly all branches of science. Due to their topological origin they

Nematic liquid crystal alignment on subwavelength metal gratings

• Irina V. Kasyanova,
• Artur R. Geivandov,
• Vladimir V. Artemov,
• Maxim V. Gorkunov and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2018, 9, 42–47, doi:10.3762/bjnano.9.6

• Irina V. Kasyanova Artur R. Geivandov Vladimir V. Artemov Maxim V. Gorkunov Serguei P. Palto Liquid crystals laboratory, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 119333 Leninsky Ave. 59, Moscow

• resonances which make such materials potentially useful in optical filters, biochemical sensors, light polarizers and other devices [3][4][5][6][7][8]. Because liquid crystals (LCs) allow for the control of such resonances using external electric and magnetic fields, the idea of combining a nanomaterial with

• a liquid crystal into a hybrid system is especially interesting as it can result in even more novel and interesting properties. In our recent work, we showed that liquid crystals strongly affect both the plasmon resonance and light polarization properties of subwavelength metal gratings [9

Study of the vertically aligned in-plane switching liquid crystal mode in microscale periodic electric fields

• Artur R. Geivandov,
• Mikhail I. Barnik,
• Irina V. Kasyanova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2018, 9, 11–19, doi:10.3762/bjnano.9.2

• Artur R. Geivandov Mikhail I. Barnik Irina V. Kasyanova Serguei P. Palto Liquid crystals laboratory, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” of Russian Academy of Sciences, 119333 Leninsky pr-t 59, Moscow, Russia 10.3762/bjnano

• experimental measurements. Keywords: electrooptics; in-plane switching; liquid crystals; vertical alignment; Introduction In 1997, Lee and co-workers discovered a new LC switching mode and called it vertically aligned in-plane switching (VA-IPS) mode [1]. At that time researchers were looking for LC modes

Magnetic field induced orientational transitions in liquid crystals doped with carbon nanotubes

• Danil A. Petrov,
• Pavel K. Skokov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2807–2817, doi:10.3762/bjnano.8.280

• first or of second order depending on the carbon nanotubes segregation intensity. Keywords: carbon nanotubes; liquid crystal; magnetic field; orientational transitions; soft coupling; Introduction In recent years suspensions of anisometric particles in liquid crystals have become of great interest for

• researchers [1]. This is not only because liquid crystals (LCs) have found wide application in modern optoelectronic devices [2] but also because anisometric particles orient like a LC in a medium that is capable of spontaneous orientational ordering. Examples of such media are suspensions of ferromagnetic or

• ferroelectric particles, as well as of carbon nanotubes. In 1970, Brochard and de Gennes proposed to dope nematic liquid crystals (NLCs) with elongated ferromagnetic particles [3]. The magnetic susceptibility of such composite system (called ferronematic), turned out to be several orders of magnitude higher

Electro-optical characteristics of a liquid crystal cell with graphene electrodes

• Nune H. Hakobyan,
• Hakob L. Margaryan,
• Valeri K. Abrahamyan,
• Vladimir M. Aroutiounian,
• Arpi S. Dilanchian Gharghani,
• Amalya B. Kostanyan,
• Timothy D. Wilkinson and
• Nelson Tabirian

Beilstein J. Nanotechnol. 2017, 8, 2802–2806, doi:10.3762/bjnano.8.279

• can be successfully used as a transparent conductive layer in LC devices. Keywords: conductive layer; graphene; ITO; liquid crystal cell; optical switching time; Introduction In modern optical devices based on liquid crystals (LCs) the electro-optical control is realized using a transparent

Thermo- and electro-optical properties of photonic liquid crystal fibers doped with gold nanoparticles

• Agata Siarkowska,
• Miłosz Chychłowski,
• Daniel Budaszewski,
• Bartłomiej Jankiewicz,
• Bartosz Bartosewicz and
• Tomasz R. Woliński

Beilstein J. Nanotechnol. 2017, 8, 2790–2801, doi:10.3762/bjnano.8.278

• transition temperature, thus improving the thermo- and electro-optical properties of the PLCF. Keywords: fiber optics; gold nanoparticle; liquid crystal; phase transition temperature; photonic crystal fiber; Introduction Since their discovery in 1888, liquid crystals (LCs) have attracted nonstop research

Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals

• Dmitrii Pavlovich Shcherbinin and
• Elena A. Konshina

Beilstein J. Nanotechnol. 2017, 8, 2766–2770, doi:10.3762/bjnano.8.275

• contamination of liquid crystals. Nematic liquid crystals with high and low initial ionic contamination have been examined. It has been shown that titanium dioxide nanoparticles reduced the ion density of liquid crystals with high initial ionic contamination from 134.5 × 1012 cm−3 to 63.2 × 1012 cm−3. In the

• case of liquid crystals with low initial ionic contamination, the nanoparticles led to an insignificant increase of ion density from 19.8 × 1012 cm−3 to 25.7 × 1012 cm−3. Keywords: ionic impurities; liquid crystals; nanoparticles; titanium dioxide; Findings Nowadays, liquid crystals (LCs) are widely

• addition, nanoparticles can induce other new functions in liquid crystals, including improved response time [14][15], surface plasmon resonance [16], and improvements in alignment [17]. The ionic contamination of LCs remains one of the challenges to LC technology. Ionic conductivity negatively affects LC

Ferrocholesteric–ferronematic transitions induced by shear flow and magnetic field

• Dmitriy V. Makarov,
• Alexander A. Novikov and
• Alexander N. Zakhlevnykh

Beilstein J. Nanotechnol. 2017, 8, 2552–2561, doi:10.3762/bjnano.8.255

• ; helix unwinding; liquid crystals; magnetic field; shear flow; Introduction The dispersing of nanoparticles of different nature (e.g., carbon nanotubes, ferromagnetic or ferroelectric particles, quantum dots, silica particles) into liquid crystals (LCs) leads to a change in the properties of the

• control are revealed. One of such materials is a ferroliquid crystal, a highly dispersed magnetic suspension of anisometric particles of a ferro- or ferrimagnet, in which the carrier liquid is a liquid crystal [10]. In contrast to pure liquid crystals, which are diamagnetic media with a quadrupole

• molecules [13]), γ1 and γ2 are the coefficients of the rotational viscosity of an LC. Liquid crystals with λ ≥ 1 are called flow-aligning LCs. If 0 < λ < 1 the orientation of the director n in the flow will not settle to a constant value but to continue to move randomly. The LCs are then called non-flow

Nanoprofilometry study of focal conic domain structures in a liquid crystalline free surface

• Anna N. Bagdinova,
• Evgeny I. Demikhov,
• Nataliya G. Borisenko and
• Sergei M. Tolokonnikov

Beilstein J. Nanotechnol. 2017, 8, 2544–2551, doi:10.3762/bjnano.8.254

• boundary. The capabilities of this new experimental method, as applied for liquid crystal free boundaries, are discussed. The formation of focal conic domain structures at the smectic-A–air free boundary was detected and studied. Keywords: focal conic domains; free boundary; liquid crystals

• ; nanoprofilometer; smectic-A phase; Introduction The free surface of liquid crystals has been a subject of great interest since the beginning of liquid crystal science. Liquid crystalline free boundary research is very important because it shows that the intrinsic free surface properties are not influenced by the

• the elastic moduli of liquid crystals. The shear modulus, G, is given as where C and C1 are scaling constants depending on surfactant, t is the relative temperature, γ is the surface tension coefficient of the free surface with FCDs, and L is the FCD dimension. This relation underlines that the

Alternating current magnetic susceptibility of a ferronematic

• Natália Tomašovičová,
• Jozef Kováč,
• Veronika Gdovinová,
• Nándor Éber,
• Tibor Tóth-Katona,
• Jan Jadżyn and
• Peter Kopčanský

Beilstein J. Nanotechnol. 2017, 8, 2515–2520, doi:10.3762/bjnano.8.251

• attention that nematic liquid crystals (LCs) have attracted in recent decades is due to the anisotropy of their physical properties. This anisotropy allows for a realignment of their director (the axis of cylindrical symmetry) by external electrical or magnetic fields, or by shear [1]. In common nematics

• susceptibility anisotropy (χa ≈ 10−6) of liquid crystals. As a way of lowering the required applied magnetic field, doping liquid crystals with magnetic nanoparticles (MNPs) has been proposed [2]. The stable colloidal suspensions of MNPs in nematic LCs are now known as ferronematics (FNs). Following the first

Dynamic behavior of a nematic liquid crystal mixed with CoFe₂O₄ ferromagnetic nanoparticles in a magnetic field

• Emil Petrescu,
• Cristina Cirtoaje and
• Cristina Stan

Beilstein J. Nanotechnol. 2017, 8, 2467–2473, doi:10.3762/bjnano.8.246

• theoretical analysis of suspensions of ferromagnetic particles in water, the so-called ferrofluids [1], or in liquid crystals [2][3][4][5][6][7][8], as well as in related experimental studies [9][10]. Optical phase modulation can be easily achieved in nematic liquid crystals (LC) subjected to external fields

• reason is the long response time of liquid crystals to the field action. The second reason is the high threshold for the Fréedericksz transition, which requires powerful DC voltage sources and large electromagnets. By using ferromagnetic particles, the response time can be reduced, but at the cost of a

• higher Fréedericksz threshold [11][12]. The unique properties of nanoparticles open new development directions not only in materials science, but also in electronics, providing considerable improvement [13]. Liquid crystals, largely used for displays, are now mixed with nanoparticles such as magnetite

Morphology of SiO₂ films as a key factor in alignment of liquid crystals with negative dielectric anisotropy

• Volodymyr Tkachenko,
• Antigone Marino,
• Eva Otón,
• Noureddine Bennis and
• Josè Manuel Otón

Beilstein J. Nanotechnol. 2016, 7, 1743–1748, doi:10.3762/bjnano.7.167

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• article, different types of tuning techniques are encompassed, for example: i) smart polymers [3][4][5][6][7], ii) liquid crystals [8][9][10][11][12], and electrophoresis [13][14][15][16]. The employment of metallic nanoparticles for the structural colour tuning with electric field, to the best of our

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a

• conductivity, where the charge transport is favored along the longitudinal axis [2]. Liquid crystals (LCs) are self-organized anisotropic fluids, well-known for their use in flat panel mobile, PC, and TV displays. Besides consumer electronic products, LCs are employed in many photonic devices such as spatial

Organized films

• Maurizio Canepa and
• Helmuth Möhwald

Beilstein J. Nanotechnol. 2016, 7, 406–408, doi:10.3762/bjnano.7.35

• disordered phases [8] that could be mapped on smectic liquid crystals. These and other studies, while revealing the interesting two-dimensional physics of Langmuir monolayers, also brought to attention some important issues in obtaining films with high geometric order extending over micrometer length scales

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• , Leganés, E28911, Spain 10.3762/bjnano.6.39 Abstract The inclusion of nanoparticles modifies a number of fundamental properties of many materials. Doping of nanoparticles in self-organized materials such as liquid crystals may be of interest for the reciprocal interaction between the matrix and the

• ; Introduction Carbon-based nanostructured materials and their relationship with liquid crystals (LC) is a hot topic in current research. It is worth mentioning the recently described connection between graphene oxide and liquid crystals [1][2], as well as the highly active topic of LC structures doped with

Anticancer efficacy of a supramolecular complex of a 2-diethylaminoethyl–dextran–MMA graft copolymer and paclitaxel used as an artificial enzyme

• Yasuhiko Onishi,
• Yuki Eshita,
• Rui-Cheng Ji,
• Masayasu Onishi,
• Takashi Kobayashi,
• Masaaki Mizuno,
• Jun Yoshida and
• Naoji Kubota

Beilstein J. Nanotechnol. 2014, 5, 2293–2307, doi:10.3762/bjnano.5.238

• been shown. In addition, proteins, Langmuir–Blodgett films (a self-organizing film), and liquid crystals have been studied as supramolecular assemblies. Moreover, the development of biomimetic polymers by using new supramolecular assemblies is expected, such as artificial enzymes with highly selective