The substantial improvement of mechanical properties of polymer nanocomposites can be attributed to high rigidity and aspect ratio of nanoclay combined with good affinity through interfacial interaction between polymer matrix and dispersed nanoclay. It is well reported that polymer nanocomposites have excellent barrier properties against O2, CO2 and water vapor. This depends on the type of clay, i.e., compatibility between clay and polymer matrix, structure of nanocomposites and aspect ratio of clay platelets. Generally good gas barrier properties of polymer nanocomposite are archived by exfoliated clay minerals with large aspect ratio [91]. Also Rhim with his co-worker reported that water vapor transmission rate of agar/unmodified montmorillonite (Cloisite Na+) nanocomposite films is significantly lower than agar/organically modified montmorillonite (Cloisite 30B, 20A) nanocomposite [88, 89]. …show more content…
Yano with his co-worker developed polyimide/clay nanocomposite films with four different sizes of clay minerals, such as hectorite, montmorillonite, saponite and synthetic mica to understand the effect of aspect ratio on the barrier properties of nanocomposite. They found that at constant clay content (2 wt%), the relative permeability coefficient decreases with increase the length of the clay [92]. Contradictorily, Cloisite 30B is more effective in reducing the water vapor permeability of poly-lactic acid based nanocomposite films and chitosan based nanocomposite film [90, 56]. Similar results about water vapor permeability of bio-nanocomposite films based on other biopolymers, such as whey protein isolate [93-94], starch [95], soy protein isolate [96-97], poly(caprolactone) [29] and wheat gluten [98] have been
Antimicrobial encapsulated into polymeric nanoparticles is a suggested novel drug delivery system to treat CRS. Nanoparticles are categorized into nanospheres (matrix-like structure) and nanocapsules (vesicular systems). Nanospheres are a type of nanoparticles that allows drug encapsulation surrounded by a polymer matrix (Pinto Reis C. et al., 2006). Literature suggests Poly Lactic-co-Glycolic Acid (PLGA) is an attractive polymer to coat the nanospheres due to their biodegradable and biocompatible properties (Makadia HK. & Siegel SJ., 2011). The nanoprecipitation solvent-diffusion method was chosen for encapsulation of the poorly water-soluble drug MUP. Initially, an oil-in-water emulsion is formed. PLGA and MUP in a 1:1...
Summer is almost here, and Kate Hudson is planning a new line of trendy fashions for her customers at Fabletics. Kate Hudson is known as an actress. She is also the co-founder of Fabletics, a company that specializes in bringing sporty chic wear to customers at a very affordable price. Hudson launched a line of swim-wear that is sure to capture the attention of Fabletics fans. She is also launching a line of summer dresses that she promises are super cute and very comfortable. In addition, Hudson states that the company has designed the clothes for every body type.
In this case study, our concern goes for the chitosan nanoparticles; firstly nanoparticles are able to adsorb and/or encapsulate a drug, thus protecting it against chemical and enzymatic degradation. Furthermore the encapsulated drug may be prevented from crystallization, thus forming a solid solution. Depending on drug solubility in the carrier, a drug load varying from only a few percent up to 50%] Secondly, chitosan is ...
We have discussed various cell-wall associated biopolymers. Select one irregular biopolymer and describe its structural arrangements in the context of molecular and supramolecular level -- draw sketches. Indicate an experimental technique that could show how the biopolymer may respond to abiotic/environmental stresses
The surface morphological changes of powder and carbon samples were investigated using a Scanning Electron Microscope (SEM). The figure 2 and 3 shows the Scanning Electron Microscopy of orange peel powder and carbon made from powder. Carbon made from powder showed more porous structure than orange peel powder. Orange peel powder showed vertical vein type structure and carbon made from powder showed more porous structure with holes which gave maximum adsorption capacity than the orange peel powder.
Biopolymer materials represent an alternative for conventional packaging materials, whereas the basic idea of their production is the savings of nonrenewable r...
It’s a quiet day on the fourth floor of the Research Pavilion building in UCF’s Research Park- or so it seems. At second glance, the halls are abuzz with professors and students dressed alike in lab coats speaking a language unknown to most commoners: the language of science.
The effect of molecular weight to the rate of diffusion of some substances was determined using two experiments that require glass tube and petri dish of agar-water gel with three wells. In the first experiment, two cottons were soaked in hydrochloric acid (HCl) and ammonium hydroxide (NH_4OH), respectively and were placed at the both ends of a glass tube simultaneously. The second experiment involved three wells filled with a drop of potassium permanganate (KMnO_4), potassium dichromate (K_2 Cr_2 O_7), and methylene blue, respectively. At a regular three-minute interval starting from zero minute to thirty minutes, the diameter (mm) of the colored area of the three substances was observed and recorded. The partial rates of diffusion
Acrylic is additionally celebrated by the trade names Lucite and Plexiglas. sold principally as a transparent glazing sheet, it should be worked properly to avoid cracking and breaking.
Starch-based snacks and ready-to-eat breakfast cereal continue to increase in sales worldwide. Starch-based snacks are commonly made in the form of puffed products. Puffed products are appreciated mainly for their lightness and crispness. These qualities are related to the air cellular structure and degree of expansion. Puffing is a process used for engineering structures and properties of food materials to give a light, airy and crispy texture (Nath and Chattopadhyay, 2008; Mariotti et al., 2006). Process for making starch-based puffed products includes gelatinization of starch, cooling, drying, and then explosive expansion (Hoke et al., 2007). After starch gelatinization, retrogradation of starch molecules, amylose and amylopectin occurred during cooling and aging of the pastes (Perdon et al., 1999; Ji et al., 2007; Mariotti et al., 2009). The amylose-amylopectin ratio, which commonly reported in term of amylose content, has been known to be an important parameter affecting physical properties of starch pastes/gels and characteristics of puffed products (Hibi and Hikone, 1998; Boischot et al., 2003; Cheow et al., 2004; Saeleaw and Schleining, 2010). The retrograded amylose prepared for the crystal nuclei, which can increase the nuclei crystal growth, so the higher amylose content, the faster starch retrograded (Biliaderis, 1992) which showed high retrogradation enthalpy (Vandeputte et al., 2003; Narpinder et al., 2006) and provided the harder gel. For rice flour mixtures, the higher amylose content gave the higher density, but the lower expansion ratio of puffed products (Chen and Yeh, 2001). The effects of AC on gel physical properties and puffed product characteristic were commonly done by mixing two different amylose conte...
Cellulose is an abundant polysaccharide consisting of a β-1, 4 linkage of D-glucose [1,3]. There is an array of applications for cellulose, including, but not limited to: biofuels, reinforcement agents, thickeners, dietary fiber, and even wound care. As of late, cellulose, as a waste product, has been in high demand as a reinforcement agent in synthetic, petroleum-based polymer matrices (petroleum based plastics) [3]. Cellulose I has good flexibility, it is abundant in nature and also biodegradable. Because of its fiber- like structure, it has been compared to carbon nanotubes (CNT’s) [3].
The amphiphilic molecules which is known as surfactants have been used widely in different industries including petroleum, environmental, food, agricultural, bioprocessing, cosmetic, and biological industries. Surfactants contain a hydrophilic part and hydrophobic part which make them capable to reduce surface and interfacial tension of liquids. However, these compounds are chemically synthesized which is mainly petroleum-based and toxic to the environment. These compounds may cause pollution to the environment because of their non-biodegradable properties (Banat et al., 2000; Fakruddin, 2013). Hence, the interest in biosurfactants increased rapidly in recent years as an alternatives to chemical surfactants (Banat et al., 2000; Lang & Wullbrandt, 1999).
Steel: (for all intents and purposes) was invented in 1855 by Henry Bessemer(Mary Bellis). Science the amazing innovation that has changed the world incredible things have been made from the material from bridged cables and cross beams to arresting wires on aircraft carriers that stop monumental force and speed. It is truly an amazing martial, but eventually it snaps, breaks or tears due to the separation of the molecules. Also steel is not the most flexible material there is which may sound good for what it is used for, construction. You wouldn’t want the floor to shift from under but, what about in areas that have a consent threat of earthquakes having a material that is rigid when needed and flexible when needed would be an invaluable asset to construction companies in many countries. Also at $600-$900 per ton(Platts Mcgraw hill financial) it isn’t the most inexpensive material that could be chosen. Chemically is there a better material that could be used in the place of steel that is stronger more flexible and can be produced for a cheaper price than the normal steel that we use today? First, the choice of spider silk seems like a great choice. Mother nature seems to be the greatest designer of all made of different sections of proteins of extremely ridged and at the same time extremely elastic strings of proteins, that when braided together are 5 times stronger than steel and relatively free to produce as long as the spiders are kept healthy. What makes the proteins so strong? They are linked together almost like thousands of Lego’s linked together which by its self does not sound very strong, but just take 3 and pull length wise and try to pull them apart, it's almost impossible. The same concept is used in the spider's silk...
I have chosen nanotechnology as my topic area of choice from the food innovation module.
C.Deepa et. al (2010) states that cement is made of a mixture of chalk or limestone together with clay. It contains adhesive and cohesive properties which allowing it to link mineral piece into a solid mass. Cement through chemical reaction (hydration) to form a hardened mass. Among different types of cement, Portland cement is the most commonly used as binding material in nowadays civil engineering. The name "Portland cement" was originated in a patent obtained by Joseph ASP din of Leeds, England in 1824.