Synthesis, characterization and diode applications of novel chitin derivatives

In this study, chitin obtained from shrimp shells was interacted with acid chlorides, carboxylic acids and anhydride. The chitin and new synthesized materials were characterized with different techniques. In addition, these diodes were characterized by forming diodes with chitin and synthesized chitin derivatives. Chitin was interacted with 3,5-dinitrobenzoyl chloride, phthaloyl dichloride, o-asetylsalicyloyl chloride, 4-nitrobenzoyl chloride, 4,5-dichlorophthalic acid, diphenic acid, coumarin-3-carboxylic acid and benzophenone-3,3',4,4'-tetracarboxylic dianhydride, respectively. The chitin and the synthesized materials were characterized by FT-IR, solid state 13C CP/MAS NMR, XRD, SEM, TGA, DSC and conductivity measurement techniques. FT-IR and 13C CP/MAS NMR spectroscopies were used to determine the structure of chitin and synthesized materials. FT-IR and 13C CP/MAS NMR spectra showed that esterification reaction is realized. Crystal size and crystalline index of the chitin and synthesized materials were compared by XRD analysis. XRD analysis results showed that synthesized materials have lower crystallinity degree according to chitin. Surface morphology of chitin and synthesized materials was determined by SEM analysis. Mass loss in chitin and synthesized materials with thermogravimetric analysis (TGA) method was determined as a function of increasing temperature. The amount of heat absorbed or released by chitin and synthesized materials with differential scanning calorimetry (DSC) technique was determined as a function of temperature. The electrical conductivity of the synthesized materials was measured and it was found that K4NK, K35DK, K45DA, KOAK, KFD, KB33'44'TD are semiconductor. Besides, the diodes of synthesized materials (Au/polymer/n-Si) were constructed, and the current-voltage (I-V) measurements of these diodes in dark and under illumination were taken. It has been used a light source of 100 mW/cm2 intensity for lighting. It was seen from I-V graphics that the diodes of synthesized materials show rectifier property. Later on, some parameters (ideality factor (n), barier height (Φb) and series resistance (Rs)) related to these diodes were calculated. Lostly, the susceptibility of these diodes to light was investigated, and some photoelectric properties related to these diodes were determined. Keywords: Chitin, polymer, synthesis, characterization, acid chloride, anhydride, schottky diode, ideality factor, barrier height