Lyotropic Liquid Crystalline Polymers
Introduction to Liquid Crystalline Polymers & Brief History
Liquid crystals (mesophase) are basically those compounds that have an intermediate state, thought of as forth state of matter. It has properties of both standard liquid and solid crystal. It can flow like a liquid, but its molecules are arranged in ordered manner. These are made from organic compounds and mostly used in displays like LCDs. (Chapoy, 1985)
Liquid crystalline polymers are basically a new and important class of some selective polymers because they provides a unique order of properties. These polymers are very high performance materials because of their multipurpose applications in modern technology. They can replace metals, ceramics
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It consists of Kevlar and other polyamides LC polymers. This surfactant have a hydrophilic and hydrophobic part. In concentrated system, liquid crystal forms due to packing of micelles. This basically gives an idea about different polymers and possible attachments on polymers. An example of such a polymer is Kevlar and polyamides.
Lyotropic Main Chain Liquid Crystal Polymers
Liquid crystalline solution are also form in Lyotropic main chain liquid crystalline polymers. In case of Lyotropic main chain liquid crystalline polymers, liquid crystalline solution formed due to the spatial arrangement of the main chain of polymer, not due to the substituent character on polymer main chain. An example of such a polymer is poly (-benzyl-L-glutamate). (Edmir Silva, 2010)
Structure of Lyotropic Liquid Crystalline polymers
At the concentration of molecules becomes higher, then molecules in solution arranged in a spherical shape, or hollow spheres called micelles. The green circles are in contact with water (hydrophilic part), while tails in inside the micelle (hydrophobic
Ionic liquids (ILs) are liquids composed entirely of ions. Molten salt is the term normally reserved for those systems that are liquid at high temperatures, for example NaCl (table salt is a liquid at ≈ 800 0C). Room-temperature ILs are liquid below 100˚C, have received considerable attention as substitutes for volatile organic solvents. Due to their remarkable properties, such as negligible vapour pressure, large liquidous range, high thermal stability, good ionic conductivity, high electrochemical stability, they are considered favourable medium candidates for chemical syntheses. ILs are usually categorized into four types based on their cation segment: 1) alkylammonium-, 2) dialkylimidazolium-, 3) phosphonium- and 4) N-alkylpyridiniumbased ILs (Figure 1). Ionic liquids are generally composed of a bulky organic cation, such 1-butyl-3 methylimidazolium and typically an inorganic anion such as a halide. Below are the chemical structures of some common cations and anions used to make ILs.
A group of polymer chains can be organised together in a fiber. How the polymer chains are put together is important, as it improves the properties of the material. The flexibility, strength and stiffness of Kevlar fiber, is dependent on the orientation of the polymer chains. Kevlar fiber is an arrangement of molecules, orientated parallel to each other. This orderly, untangled arrangement of molecules is described as a “Crystalline Structure”. A manufacturing process known as ‘Spinning’ is needed to achieve this Crystallinity structure. Spinning is a process that involves forcing the liquefied polymer solution through a ‘die’ (small holes).
You have been asked to design an oral liquid formulation of ibuprofen for paediatric use.
...nstead of the common crystalline state, something that is extremely hard (gizmodo.com). That’s where the liquid levitation comes in, a machine that uses sound waves to make liquid solutions float. This way the liquid solutions don't touch any solid materials as the water evaporates, solidifying in the much desired amorphous drug, so it can be more efficient in helping.
According to osmosis theory as the concentration of the sucrose solution increases the particles water potential increases and becomes higher than the particles that are in the
In order to separate the mixture of fluorene, o-toluic acid, and 1, 4-dibromobenzene, the previously learned techniques of extraction and crystallization are needed to perform the experiment. First, 10.0 mL of diethyl ether would be added to the mixture in a centrifuge tube (1) and shaken until the mixture completely dissolved (2). Diethyl ether is the best solvent for dissolving the mixture, because though it is a polar molecule, its ethyl groups make it a nonpolar solvent. The compounds, fluorene and 1, 4-dibromobenzene, are also nonpolar; therefore, it would be easier for it to be dissolved in this organic solvent.
This maximises the intermolecular forces between the chains as they are able to pack closely together. However, this reduces the flexibility and is therefore quite rigid and strong. This isotactic polyvinyl chloride structure occurs very little. Another structure that is produced very little is the syndiotactic PVC. The syndiotactic PVC has a regular arrangement and has similar properties of flexibility, rigidity and strength to the isotactic PVC as shown in Figure #.
This is because the water molecules pass from a low concentration to a high concentration, (in the potato chip). Therefore, the chips in low concentrations will gain mass and have a greater length height than in higher concentrations such as 1molar of sugar solution. If there is no gain or loss in height or mass then these will be the isotonic points of the potato cells. The isotonic point is where the cells are not increasing or decreasing in size and is known to be in a state of equilibrium. Apparatus: 1.
Slime is a special play material made up of tangled polymer. It is mostly made by mixing polyvinyl with the chemical compound known as borate ions, you can describe it as a liquid and mix it in a sizable container for mixing. In a more difficult explanation, slime is more commonly known amongst scientists as a Non-Newtonian fluid. These are thick liquids that have a numerous selection of viscosity.
The ingredients used in making slime contain fundamental additives that, when mixed together, cause the thick, gooey, slime every kid enjoys. Polymers are made from several smaller molecules joined by chemical bonds. The polyvinyl allows the mixture to feel slimy. Combing the polyvinyl and Borax together creates a chemical reaction. The mixture becomes cold, thicker, and elastic. This combination mixed together produces slime that is fun and safe for all ages.
Polymer-Polyethylene is partially crystalline as well as amorphous because it has crystalline and amorphous regions. Also it has linear chains so this is the simplest structure compared to a branched or network chain. This can be of an advantage to it over other types of materials as its good toughness and elongation makes it very significant in the engineering industry as it can be moulded or extruded into shape...
chains instead of hydrogen atoms. Cross-linking is another way in which the polymer can be made stronger. This involves ultraviolet radiation that bombards the polymer with electrons and formulates bonds between the molecular chains of the polymers. This is like linear polyethylene but different in that it is more impact resistant, and it has a much higher density. This allows it to be stored or be used with different chemicals that would normally cause the polymer to desolve.3 This can start to become a problem because as the polymer continues to become chemically enhanced. So the ways of dissolving and recycling the polymer become more difficult.
This is an example of a soap molecule. The hydrocarbon end is non polar and hydrophilic (water hating) and the carboxylate end is polar and hydrophilic (water loving). This the property which allows it to clean, it acts as an emulsifying agent. The soap disperses in water to form miscelles where a negatively charged surface is formed and hydrocarbon chains are in the centre. These miscelles surround droplets of dirt or grease suspending them in the water so they can be washed away.
We were all taught that there were four states of matter: Solids, Liquids, Gases, and Plasma, but some states of matter cannot be defined by one the these four. One of which are liquid crystals. These crystals have properties of both liquids and solids. They physically flow like liquids, but also share characteristics of crystalline solids. There is also more then one type of liquid crystals along with their different phases. Since they have so many properties, its no wonder how much we use them today. They can be found in the majority of today’s electronics and technologies.
Liquids have no definite shape. Liquids are less orderly than solids but more orderly than gases. Liquids can flow very easily. Liquids also take the shape of their container.