scholarly journals Preparation of Fibrillated Cellulose from Kenaf Bast Fiber using High Speed Homogenizer without Pressure

The aim of the study is to characterize the fibrillated cellulose (FC), which has been extracted from kenaf bast fiber using high speed homogenizer (HSH). The FC was prepared by applying 10,000, 15,000 and 20,000 rpm of homogenization process for 10, 15 and 20 mins. Morphological observation via Field Emission Scanning Electron Microscope (FESEM) was carried out in order to observe the sur-face morphology of FC while Fourier Transform Infrared (FTIR) spectroscopy was performed to determine the changing of functional groups. Thermogravimetric Analysis (TGA) was done for thermal decomposition of FC. Results showed that the diameter of the FC from kenaf bast was determined below 100 nm. The Fourier Transform Infrared (FTIR) spectroscopy showed that lignin and hemicellulose were almost completely removed during the bleaching process at peak 1,737 cm-1. In addition, thermogravimetric analysis (TGA) displayed 272°C as the highest temperature for thermal stability of FC. In conclusion, by controlling the speed during homogenization process, FC was successfully obtained. Such FC can be applied as beneficial main ingredients in papermaking and packaging industry, which dedicat-ed to mechanical strength properties.

2021 ◽  
pp. 002580242110109
Author(s):  
Sweety Sharma ◽  
Rito Chophi ◽  
Jaskirandeep Kaur Jossan ◽  
Rajinder Singh

The most important task in a criminal investigation is to detect and identify the recovered biological stains beyond reasonable scientific doubt and preserve the sample for further DNA analysis. In the light of this fact, many presumptive and confirmatory tests are routinely employed in the forensic laboratories to determine the type of body fluid. However, the currently used techniques are specific to one type of body fluid and hence it cannot be utilized to differentiate multiple body fluids. Moreover, these tests consume the samples in due process, and thus it becomes a great limitation especially considering the fact that samples are recovered in minute quantity in forensic cases. Therefore, such limitations necessitate the use of non-destructive techniques that can be applied simultaneously to all types of bodily fluids and allow sample preservation for further analysis. In the current work, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy has been used to circumvent the aforementioned limitations. The important factors which could influence the detection of blood such as the effect of substrates, washing/chemical treatment, ageing, and dilution limits on the analysis of blood have been analysed. In addition, blood discrimination from non-blood substance (biological and non-biological in nature) has also been studied. Chemometric technique that is PCA–LDA has been used to discriminate blood from other body fluids and it resulted in 100% accurate classification. Furthermore, blood and non-blood substances including fake blood have also been classified into separate clusters with a 100% accuracy, sensitivity, and specificity. All-inclusive, this preliminary study substantiates the potential application of ATR-FTIR spectroscopy for the non-destructive identification of blood traces in simulated forensic casework conditions with 0% rate of false classification.


1976 ◽  
Vol 30 (6) ◽  
pp. 593-601 ◽  
Author(s):  
R. R. Willey

This paper describes a new Fourier transform infrared spectrophotometer with the capability to measure diffuse reflectance (DR) from 5000 to 500 cm−1 (2 to 20 µm) in addition to the normal transmittance measurements. The instrument has a true simultaneous double beam measurement mode and a high speed single beam mode. The system also takes advantage of many data manipulation and display features due to the built-in computer and 2.5 million word storage system. One of the objectives of this work was to produce a practical instrument which includes the DR capability; another was to introduce the qualitative and quantitative measurements of DR in the infrared to the analytical community. DR has been commonly available in the visible and near ir spectrum, but until this new instrument, has not been available in the ir. A brief survey of the background and history of DR and emittance measurements in the ir is given. The design details and operation of the instrument are generally examined. Brief examples are provided for a few transmittance, trace analysis, and microsampling applications, and a variety of DR results are shown. The addition of diffuse reflectance as a tool in the infrared opens new avenues for investigation and application in many fields.


2021 ◽  
pp. 152808372110592
Author(s):  
Vahid Shakeri Siavashani ◽  
Gursoy Nevin ◽  
Majid Montazer ◽  
Pelin Altay

Flexible sensors and wearable electronics have become important in recent years. A good conductive and flexible textile is needed to develop a commercial wearable device. Conductive polymers have generally been used with limitation in reducing the surface resistance to a certain amount. In this research, a method for fabricating a stretchable highly conductive cotton/lycra knitted fabric is introduced by treating the fabric with polypyrrole (PPy), silver nanoparticles (SNPs) composites, and post-treating with poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT:PSS). Polypyrrole and SNPs were in situ fabricated on the cotton/lycra fabric by consecutive redox reaction of silver nitrate and pyrrole and finally covered by PEDOT:PSS solution through dip-coating. The coated textile was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray mapping, and energy dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy confirmed PPy-SNPs (P-S) composites on the fabric surface. Fourier transform infrared spectroscopy results, X-ray mapping, EDAX, and XRD analysis also confirmed the P-S composites and PEDOT:PSS polymeric layer on the fabric. Morphological observation showed a layer of PEDOT:PSS on the P-S caused the higher connection of coating on textiles which resulted in the higher electrical conductivity (43 s/m). Also morphological observations showed penetration of the silver particles inside fibers which represented improving in attachment and stability of the coating on the fibers. Further, the electrical conductivity of PPy-SNPs-PEDOT:PSS coated textile increased under the tension. Hence, the stretchable and highly conductive knitted cotton/lycra fabric has potentiality to be used for fabricating the flexible sensors or wearable electronics.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1997 ◽  
Author(s):  
Zhi Wang ◽  
Ruichao Wei ◽  
Xuehui Wang ◽  
Junjiang He ◽  
Jian Wang

To fill the shortages in the knowledge of the pyrolysis and combustion properties of new and aged polyvinyl chloride (PVC) sheaths, several experiments were performed by thermogravimetric analysis (TG), Fourier transform infrared (FTIR), microscale combustion calorimetry (MCC), and cone calorimetry. The results show that the onset temperature of pyrolysis for an aged sheath shifts to higher temperatures. The value of the main derivative thermogravimetric analysis (DTG) peak of an aged sheath is greater than that of a new one. The mass of the final remaining residue for an aged sheath is also greater than that of a new one. The gas that is released by an aged sheath is later but faster than that of a new one. The results also show that, when compared with a new sheath, the heat release rate (HRR) is lower for an aged one. The total heat release (THR) of aged sheath is reduced by 16.9–18.5% compared to a new one. In addition, the cone calorimetry experiments illustrate that the ignition occurrence of an aged sheath is later than that of a new one under different incident heat fluxes. This work indicates that an aged sheath generally pyrolyzes and it combusts more weakly and incompletely.


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