How to make silk Essay

PROCURING SILK COCOON:

The shinning bright and white coloredBombyx moriare procured from the Siddlagatte, Chikballapur territory, Karnataka ( INDIA ) shown in figure A The fiber thickness of these stuffs is about 10micro metre in size. These are porous in construction. The interior surface is smoother than the outer surface. The cocoons were cleaned with a electric blower after taking the pupae and maintain in a plastic box for farther usage.

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ALUMINIUM FOIL:

SUPERWRAP Aluminum foil is purchased. It has a thickness of 11 micrometers, width 290mm, Length of 72m and net weight 15g. These are impermeable to oxygen and H2O. It has a glistening side and a flat side. Figure B

Vinegars:

Heinz Vinegar is purchased at Bangalore. It consists of 5 % v/v acetic acid. Figure C

X-RAY DIFFRACTION ( XRD )

Rigaku Ultimate IV X-ray diffractogram ( Department of nanotechnology, Muddenahalli ) is used, shown in figure B to obtain the structural constellation of silk cocoon of pure cocoon, cocoon coated with black lead and cocoon coated with decreased graphene oxide. The X ray is operated at 40v, 30mA, with a scan scope from 10.0000 – 70.0000 grade. Scan velocity of 2 deg./min, step breadth of 0.02 deg. , The Cross Beam Optics ( CBO ) choice slit is BB and filter used is K-beta filter.

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The dimension of slide is Height 1600 millimeter, Width 1100 millimeter, Diameter 800mm. sample tallness is 1050 millimeter. The package used is PDXL, a one-stop full-function pulverization diffraction analysis package suite. It is a user friendly GUI, used provides assorted analysis tools such as automatic stage designation, quantitative analysis, crystallite-size analysis, lattice invariables polish, Rietveld analysis, ab initio construction finding, etc.

X raies are electromagnetic moving ridges like ordinary visible radiation, therefore they should exhibit interface and diffraction. The wavelength of X raies is of the order of 0.1nm. X raies are electromagnetic radiations with typical photon energies in the scope of 100 eV-100 keV. These energetic X raies can perforate deep into the stuff and supply information about the structural agreement of atoms and molecules [ 50-51 ] . When a focussed negatron beam accelerated across a high electromotive force field bombards a stationary or revolving solid mark. As negatrons collide with atoms in the mark and decelerate down, a uninterrupted spectrum of Xrays are emitted, which are termed Brems strahlung radiation. The high-energy negatron beam besides ejects interior shell negatrons in atoms through the ionisation procedure. When a free negatron fills the shell, an X-ray photon with energy feature of the mark stuff is emitted. Common marks used in X-ray tubings include Cu and Mo, which emits 8 keV and 14 keV, X-rays with matching wavelengths of 1.54 A and 0.8 A , severally [ 51 ] .

A simple reading of the diffraction form was given by W.L. Bragg. He reported that the musca volitanss spota are produced due to the contemplation of some of the incident X raies from the assorted set of the parallel crystal planes, called bragg’s plane which contain a big figure of atoms. The undermentioned figure shows the contemplation of X raies from lattice planes in the crystal.

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Harmonizing to the Bragg’s equation, which is given by

2d sini?± = ni?¬

Where vitamin D is the interplanar difference spacing of planes and n = 1,2,3… . Represents the innterger value of order like first order, 2nd order etc. , respectiviely, i?¬ is the wavelength of the xrd and i?± is the incident angle steps in grade. The incident beam and reflected beam all doing the angle theta with a crystal plane. Contemplations from planes set at thetaangle with regard to the incident beam generates a reflected beam at an angle 2-thetafrom the incident beam.

XRD has legion advantages like non-destructive nature, high sensitiveness, dependability, deepness profiling ( peeking incident angle ) , easy sample readying, system is user friendly, operational process is convenient, fast velocity, effectual declaration, low care cost, proper mechanization, easy informations reading that could be used for both qualitative and quantitative analysis, in broad scope of applications. However, it has a few disadvantages due to utilize of harmful radiations furthermore there is demand of standard mention to fit for an illation and an expensive instrument. It is used to analyze the crystalline content, place the crystalline stages, spacing between lattice planes, graduated tables of being, discriminatory order and epitaxial growing of crystallites [ 53 ] .

Example for ciphering inter planar distance utilizing Bragg’s equation for Cu. The extremum for Cu is at 2i?± = 43.2? and wavelength of 0.154 nanometers.

D = ( i?¬/ 2sini?± )

D = ( 0.154/ 2 wickedness ( 43.2/2 ) )

D = 0.2090nm — equation 1

Equation 1 shows the inter planar distance of 0.209 nanometers in the Cu. Thus Properties of nano stuffs depend on crystals size and non particle size. PXRD can mensurate 1000000s of crystals and accurately find the size distribution of nano stuffs. It can be widely used for analyzing the nature of polymers and complexs in Material Science [ 54-55 ] .

Scanning ELECTRON MICROSCOPY:

Zeiss ULTRA 55 field emanation scanning negatron microscope, shown in figure C is used to obtain the morphologies of the pure cocoon, cocoon coated with black lead and cocoon coated with decreased graphene oxide. Oxford 10mm SDD sensor is used for X-ray analysis and function. It has field emanation electron beam beginning with 1nm SEM imaging declaration. Energy diffusing x-ray spectrometry is calculated utilizing zeiss instrument. It has a Beam current up to 100 sodiums and Sub-nm declaration at 15 kilovolt. Operating electromotive force scope is 30kV.

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A normal scanning negatron microscope operates at a high vacuity. The basic rule is that a beam of negatrons is generated by a suited beginning, typically a tungsten fibril or a field emanation gun. The negatron beam is accelerated through a high electromotive force ( e.g. : 20 kilovolt ) and pass through a system of apertures and electromagnetic lenses to bring forth a thin beam of electrons. , so the beam scans the surface of the specimen by agencies of scan spirals ( like the topographic point in a cathode-ray tubing “ old-style ” telecasting ) . Electrons are emitted from the specimen by the action of the scanning beam and collected by a suitably-positioned sensor. The beam scanning the specimen surface is precisely synchronised with the topographic point in the screen that the operator is watching. The negatron sensor controls the brightness of the topographic point on the screen – as the sensor “ sees ” more negatrons from a peculiar characteristic, the screen brightness is increased. When there are fewer negatrons, the topographic point on the screen gets darker. The magnification of the image is the ratio of the size of the screen to the size of the country scanned on the specimen. If the screen is 300 millimeter across and the scanned country on the specimen is 3 millimeter across, the magnification is x100. To travel to a higher magnification, the operator scans a smaller country ; if the scanned country is 0.3 millimeter across, the magnification is ten 1000, and so on.

There are different types of negatron image. The two most common are the secondary negatron image ( sei ) and the backscattered negatron image ( bei ) . The sei is used chiefly to image break surfaces and gives a high declaration image. The bei is used typically to image a polished subdivision ; the brightness of the bei is dependent on the atomic figure of the specimen ( or, for compounds, the mean atomic figure ) . For illustration, lead will look brighter than Fe and Ca oxide will look brighter than Ca carbonate. The bei is, in kernel, an atomic figure map of the specimen surface.

Energy-dispersive X-ray microanalysis ( EDX, for brevity ) is complementary to SEM. It enables the operator to find the composing of the characteristics in the SEM image. The rule of EDX is that the negatron beam generates X raies within the specimen. Many of these X raies have energies characteristic of the elements that emitted them.

There are three chief constituents to a basic EDX system: the X-ray sensor ; a box of electronics called the “ pulse processor ” that measures the electromotive force pulses matching to the X-ray energies, and a computing machine, typically a Personal computer. The X-ray sensor is positioned to stop X raies emitted from the specimen. On come ining the sensor, an X-ray generates a little current, which is so converted into a electromotive force pulsation. The size of the electromotive force pulsation is relative to the energy of the X ray.

NUCLEAR MAGNETIC RESONANCE:

All ssNMR spectra is recorded utilizing ECX400- Jeol 400 MHz High Resolution Multinuclear FT-NMR Spectrometer, shown in Figure D. For 100.55 MHz for13C and 105.749 MHz enemy23Na frequences with Brukers 3.2 DVT investigation. The charming angle spinning ( MAS ) velocities were recorded at 10 KHz. 13c cross polarisation ( P ) spectra were recorded with incline cross polarisation sequence of 3.5ms. Samples were recorded with 1k informations point and acquisition clip of 29.10ms for13C, 38.66ms for23Na for every sample.

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Nuclear Magnetic Resonance ( NMR ) spectrometry is an analytical chemical science technique used in quality control and research for finding the content and pureness of a sample every bit good as its molecular construction.NMR can be used to find molecular conformation in solution every bit good as analyzing physical belongingss at the molecular degree such as conformational exchange, stage alterations, solubility, and diffusion.

The rule behind NMR is that many karyons have spin and all karyons are electrically charged. If an external magnetic field is applied, an energy transportation is possible between the base energy to a higher energy degree ( by and large a individual energy spread ) . The energy transportation takes topographic point at a wavelength that corresponds to radio frequences and when the spin returns to its base degree, energy is emitted at the same frequence. The signal that matches this transportation is measured in many ways and processed in order to give an NMR spectrum for the karyon concerned. They are assorted types of atomic magnetic spectra are available like1H,13C etc. , [ 56 ] .

Chemical Shift

The precise resonating frequence of the energy passage is dependent on the effectual magnetic field at the karyon. This field is affected by negatron screening which is in bend dependant on the chemical environment. As a consequence, information about the karyon ‘ chemical environment can be derived from its resonating frequence. In general, the more negatively charged the karyon is, the higher the resonating frequence. Other factors such as pealing currents ( anisotropy ) and bond strain affect the frequence displacement. It is customary to follow tetramethylsilane ( TMS ) as the proton mention frequence. This is because the precise resonating frequence displacement of each nucleus depends on the magnetic field used. The frequence is non easy to retrieve ( for illustration, the frequence of benzine might be 400.132869 MHz ) so it was decided to specify chemical displacement as follows to give a more convenient figure such as 7.17 ppm. [ 56 ] .

C environment

chemical displacement ( ppm )

C-C

0 – 50

C-O

50 – 100

C=C

100 – 150

C=O

150 – 200

The above tabular array shows the chemical displacement scope in the spectra and its several C environment. For illustration as 3-buten-2-one and its several spectra shown below.

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Here is the construction for the compound:

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The extremums are analyzed utilizing the tabular array above. The extremum at 200 is due to a carbon-oxygen dual bond. The two extremums at 137 and 129 are due to the Cs at either terminal of the carbon-carbon dual bond. And the extremum at 26 is the methyl group which is joined to the remainder of the molecule by a carbon-carbon individual bond.

Electrical MEASUREMENT:

Electrical measurings are performed utilizing Keithley’s instrument Inc. SCS-4200 semiconducting material word picture system ( IISC Bangalore ) . It has high truth and sensitiveness to mensurate really low currents. It has the ability to step resistances up to 1052 a?? . The electrical measurings are carried out for pure cocoon, cocoon coated with black lead and cocoon coated with graphene. All measurings were taken in electromotive force expanse manner for the electromotive force applied between -10V to 10V.

The rule of current – electromotive force features are the graph plotted between the electric current generated by a circuit for the electromotive force applied between the terminuss. It is a tool used to find and understand the basic parametric quantities of a constituent or device and which can besides be used to mathematically pattern its behaviour within anelectronic circuit.

The consequence of I-V for pure cocoon and cocoon coated with black lead shows the resistance behaviour, which implies the current is additive to voltage and cocoon coated with decreased graphene oxide shows the features of rectifying tube. If the electrical supply electromotive force, Vapplied to the terminuss of the resistive elementRabove was varied, and the resulting current, Imeasured, this current would be characterized as: I = V/R, being one of Ohm’s Law equations [ 57 ] .

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Electrochemical IMPEDANCE SPECTROSCOPY

Electro chemical measurings were carried out utilizing CHI604E instrument of theoretical account 600 series to analyze the cyclic V gm and electric resistance spectra for pure cocoon, cocoon coated with black lead, cocoon coated with graphene.The Initial and high electric electromotive force is given between -0.8 to 0.15 V. All cocoon scan rate is 0.01 V/S with a sample interval of 0.001 V. AC electric resistance is calculated with high frequence of 1e+6 Hz, low frequence of 1Hz and amplitude of 0.005 V.

Cyclic Voltammetry ( CV ) is an electrochemical technique which measures the current that develops in an electrochemical cell under conditions where electromotive force is in surplus of that predicted by the Nernst equation. CV is performed by cycling the potency of a on the job electrode, and mensurating the ensuing current. The Nernst equation is an equation that relates the decrease potency of a half-cell at any point in clip to the standard electrode potency, temperature, activity and reaction quotient of the implicit in reactions and species used.

The electrolysis cell consists of a on the job electrode, counter electrode, mention electrode, and electrolytic solution. The working electrode’s potency is varied linearly with clip, while the mention electrode maintains a changeless potency. The counter electrode conducts electricity from the signal beginning to the working electrode. The intent of the electrolytic solution is to supply ions to the electrodes during oxidization and decrease. A potentiostat is an electronic device which uses a dc power beginning to bring forth a possible which can be maintained and accurately determined, while leting little currents to be drawn into the system without altering the electromotive force. The current-to-voltage convertor measures the ensuing current, and the informations acquisition system produces the ensuing voltammogram [ 59-66 ] .

AC electric resistance spectrometry is a valuable tool for analyzing both the majority conveyance belongingss of a stuff and the electrochemical reactions on its surface [ 67-68 ] . Typically, AC electric resistance experiments are carried out over a broad scope of frequences ( several millihertz to several MHz ) , and the reading of the ensuing spectra is aided by analogy to equivalent circuits affecting simple constituents such as resistances and capacitances. In general, such tantamount circuits are non alone, and so there exists an infinite set of circuits that can stand for any given electric resistance [ 69 ] .

Equivalent circuit mold of EIS information is used to pull out physically meaningful belongingss of the electrochemical system by patterning the electric resistance informations in footings of an electrical circuit composed of ideal resistances ( R ) , capacitances ( C ) , and inductances ( L ) . Because we are covering with existent systems that do non needfully act ideally with procedures that occur distributed in clip and infinite, we frequently use specialised circuit elements. These include the generalised changeless stage component ( CPE ) and Warburg component ( ZW ) . The Warburg component is used to stand for the diffusion or mass conveyance electric resistances of the cell. In the tantamount circuit parallel, resistances represent conductive tracts for ion and negatron transportation. As such, they represent the majority opposition of a stuff to bear down conveyance such as the opposition of the electrolyte to ion conveyance or the opposition of a music director to electron conveyance. Resistors are besides used to stand for the opposition to the charge-transfer procedure at the electrode surface. Capacitors and inductances are associated with space-charge polarisation parts, such as the electrochemical dual bed, and adsorption/desorption procedures at an electrode, severally [ 70-71 ] .

If the electric resistance spectra collected from assorted ionic and electronic music directors ( MIECs ) , where the MIEC is placed between two metal electrodes, is the presence of a half tear-drop-shaped characteristic in the Nyquist ( Zimag versus Zreal ) representation. The earliest intervention of a related job is the authoritative work of Warburg, who studied diffusion under AC conditions in an electrolyte placed between two indistinguishable electrodes [ 70-71 ] ."C:UserssindhuIMG_20150303_124018.jpg"

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