Photodegradation of Dyes From Cual Batik Waste Using TiO2 Photocatalyst From Ilmenite Bangka

Cual batik is one of the local products of the Bangka Belitung Islands. The expansion of cual batik in Bangka Belitung continues to increase, resulting in an increase in the production of cual batik cloth. Cual batik contains remasol dyes which are carcinogenic so that waste handling is appropriate and safe for the surrounding environment. One of them is using the TiO2 photocatalytic method from ilmenite Bangka. The results of XRF characterization showed that the TiO2 content after magnetic separator and HCl washing reached 69,975% and 77,260%. The results of XRD characterization showed that the optimal temperature of calcination was at 700ºC with the peak diffraction intensity of anatase TiO2 crystals at 2θ 48.9º, 53.53º and 53.92º. In FTIR characterization, there is a functional group spectrum of titanium dioxide (TiO2) at the absorption wave number 795 cm-1 showing Ti-O-Ti stretching vibrations, at wavenumber 2326 cm-1 showing Ti-O stretching vibrations. The results of photodegradation of cual batik waste showed a decrease in the dye content of remazol briliant blue when exposed to UV lamps and sunlight at contact times of 30, 60, and 90 minutes 85.21%, 82,75%, and 86,72% (UV light); 70,75%, 78,92%, and 93.51% (sunlight).

Dielectric spectroscopy of aluminum oxide (γ-Al2O3)

Aluminum oxide (Al2O3) are continuously demonstrating the functional characteristics in devices. The physiochemical properties of hydrothermally as-grown Aluminum oxide (Al2O3) have been investigated in this research article. The as-prepared material was confirmed as γ- phase formation of Al2O3. The average crystallite size was found ∼ 78 nm, whereas the particles were found in nano scale too. Moreover, the absence of impurity in EDS analysis, and the presence of the bending vibrations of Al-O-Al and Al-O band in FTIR characterization further confirmed the absence of impurity in the material. Evaluated dielectric properties such as a relatively high dielectric constant, and low dielectric loss indicated the good optical quality of γ- Al2O3. Impedance and modulus spectroscopic studies showed the non-Debye type relaxation in γ- Al2O3 with an average relaxation time of 5.8 μs. Overall, the dielectric spectroscopy analysis of γ- Al2O3 indicates the promising applications of γ- Al2O3 in devices as dielectrics.

Glass Powder Additive on Recycled Polypropylene Filaments: A Sustainable Material in 3D Printing

This study aimed to characterize the effect of a glass powder additive on recycled polypropylene (rPP) materials from food packaging to be used as filaments in material extrusion (MEX) 3D printing applications. The composite filaments studied were rPP filaments with glass powder (GP) additive in the 2.5%, 5%, and 10% fractions. As a baseline, the filaments made of pure virgin PP and rPP without additive were used. The filament that has been successfully made is then printed into a tensile test specimen and an impact test to observe its mechanical properties. Fourier-transform infrared spectroscopy (FTIR) characterization was also carried out to determine the effect of chemical bonding and thermal characterization using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results of FTIR characterization on the sample rPP + 10% do not show a typical peak shift of PP, but give rise to new peaks at wavenumbers of 1000 cm−1 (Si-O-Na), 890 cm−1 (Si-H) and 849 cm−1 (O-Si-O), which indicate the typical peaks of the glass constituent compounds. In the thermal characteristics, the addition of GP shows the improved stability of mass changes to heat and increases the melting temperature of rPP. The ultimate tensile strength and Young’s modulus for rPP-based specimens with 10% GP additive showed an increase of 38% and 42% compared to PP specimens. In addition to the improved mechanical strength, the addition of GP also reduces the bending deformation, which can be well controlled, and reduces curvature, which is a problem in semicrystalline polymer-based filaments.

Enhanced Refractive Index Sensing Performance Using Hydrothermally Prepared Tricomposite Nanoflower Structure of Ta2O5:Si:Graphite

We describe a tricomposite nanoflower structure based method to measure the trace amount of refractive index in aqueous solutions. It utilizes tantalum (v) oxide, silicon and graphite to fabricate the tricomposite nanostructures. The tricomposite nanoflower structures were prepared using hydrothermal method where the concentration of (x) of Si in Ta2O5 was varied while the concentration of graphite was kept constant. The concentration of Si in Ta2O5 was measured by Maxwell-Garnett model using volume filling factor 'f' (0≤f≤1) of Si in Ta2O5. The fabricated Ta2O5:Si:Graphite tricomposite nanoflower structures were characterized by SEM, XRD, UV-Vis, PL, FTIR characterization techniques. Then aqueous solution of varying refractive indices were prepared in the range 1.33-1.39 in the already prepared tricomposite nanoflower structure solution. The refractive index measurement were probed by measuring absorption spectra corresponding to each tricomposite nanoflower structures. The performance of the sensor was explored in terms of shift in peak absorption spectra, sensitivity and moreover the limit of detection. The sensor shows sensitivity and limit of detection of (156-260) nm/RIU and 5.14x10-3 RIU respectively. A linear declining of sensitivity was observed within the refractive index range. The sensor possesses a distinguished feature of using tricomposite nanoflower structure which is an efficient method for refractive index measurement.

Microwave-Assisted Synthesis of Polylactic Acid-Diol for Polyurethane as Biodegradable Packaging Material

Since its discovery, plastic has been a part of human life and is widely employed in our daily lives. Excessive use of plastic has raised pollution rates around the world, with plastic ending up in landfills or the sea, posing a threat to both terrestrial and aquatic life. Considering this problem, the widespread use of polyurethanes (PUs) in many industries has resulted in unavoidable PUs pollution in everyday life. A reaction involving prepolymer, isocyanate, and polyol can be used to make PUs. Petroleum-based polyol and vegetable oil-based polyol are the two types of polyols available. Isocyanate will become the hard domain of the polymer in the PUs polymer chain, while polyol will become the soft domain. Polylactic acid-diol is the prepolymer used to make PU (PLA-diol). PLA-diol was previously made using a traditional heating approach, which takes a long time. To overcome this traditional method, microwave-assisted synthesis is proposed to synthesize the PLA-diol. The synthesis process involved synthesizing PLA-diol at different microwave power (450W – 900W) and at different reaction time (1 hour – 2 hours). The peak of hydroxyl group in synthesized PLA-diol was characterized via the Fourier Transform Infrared Spectroscopy (FTIR) characterization to determine the functional groups of PLA-diol and gel permeation chromatography (GPC) characterization was done to determine the molecular weight of PLA-diol. The resulting PLA-diol will then be used to synthesis biodegradable PUs in the subsequence study.

Application of uCT-scan and infrared spectroscopy for determination of urinary stone components

Abstrak. Batu kemih merupakan salah satu penyakit dengan tingkat prevalensi yang cukup tinggi di Indonesia. Pengetahuan komposisi pada kandungan batu kemih dapat membantu tenaga medis dalam melakukan justifikasi penanganan tindakan lanjut pada pasien dengan tepat.Tujuan penelitian iniadalah menentukan kandungan mineral yang terdapat pada batu kemih menggunakan metode analisa spektrum inframerah dan nilai hounsfield unit (HU) yang terdapat pada citra yang dihasilkan dari modality mCT-Scan. Hasil karakterisasi fourier transform infrared spectroscopy (FTIR) memperlihatkan kandungan mineral batu kemih terdiri dari batu kemih calcium oxlate monohydrate, uric acid, batu campuran calcium oxalate dengan phosphate dan batu campuran cystine dengan phosphate sedangkan hasil dari scanning mCT memperlihatkan adanya kandungan mineral batu kemih campuran seperti batu campuran calcium oxalate dan cystine, batu campuran calcium oxalate, struvite, dan cystine, dan batu campuran calciumoxalate dan uric acid.Dari hasil penelitian ini dapat disimpulkan bahwa kedua modaliti tersebut mampu memperlihatkan kandungan mineral batu kemih dengan baik. Hal ini terlihat adanya spektrum serapan karakteristik dari FTIR setiap sampel berbeda-beda dan dari hasil citra mCT-Scan memperlihatkan nilai HU yang bervariasi sehingga mengindikasikan kandungan mineral pada sampel batu kemih yang diamati juga memiliki jenis yang berbeda-beda. Abstract. Urinary stones are a disease with a high prevalence rate in Indonesia. Knowledge of the composition of the urinary stone is an essential part to determine suitable treatments for patients. The aim of this research is to determine the mineral contained in urinary stones using the infrared spectrum and the value of HU (hounsfield unit) from the image mCT-Scan. The results of FTIR characterization showed that the mineral content of urinary stones consisted of calcium oxlate monohydrate, uric acid, calcium oxalate and phosphate mixed stones and cystine-phosphate mixed stones. mCT-Scan results showed the mineral content of urinary stones such as calcium oxalate and cystine mixed stone, calcium oxalate, struvite, and cystine mixed stones, and calcium oxalate and uric acid mixed stones. This show that the two modalities are be able to determine the mineral content of urinary stones. It can be seen that the characteristic absorption spectrum of the FTIR for each sample is different and from the mCT-Scan image results, the HU value varies so that it indicates the mineral content of the observed urine stone sample are different.

Optical, Morphological, and Structural Properties of Porous Silicon Tablets.

Porous silicon (PS) is a material whit a great interest due to its optical (photoluminescent) and chemical (reactive surface) properties, for this reason, it is important to find new ways to be applied in the development of new devices. In this work the optic, chemical and morphologic properties of PS compressed into a tablet were characterized. The porous silicon was removed physically from the crystalline silicon and then was compressed to obtain a tablet. The optical characterization was performed through photoluminescence (PL) spectra. The PL spectrum from the PS tablet showed a small shift to lower wavelengths in comparison with the PS layers used to obtain the tablet. The x-ray diffraction pattern showed a loss in PS tablet crystallinity after being subjected to the compression process. The morphological characterization was carried out with a scanning electron microscope and showed a compact surface with high rugosity. This result was supported by the profilometry analysis, which also showed an irregular surface. The chemical properties of the surface were characterized with Fourier transform infrared spectroscopy (FTIR). The FTIR characterization showed an oxidized and highly hydrogenated surface.

Synthesis and Characterization of Porous, Electro-Conductive Chitosan–Gelatin–Agar-Based PEDOT: PSS Scaffolds for Potential Use in Tissue Engineering

Herein we report the synthesis and characterization of electro-conductive chitosan–gelatin–agar (Cs-Gel-Agar) based PEDOT: PSS hydrogels for tissue engineering. Cs-Gel-Agar porous hydrogels with 0–2.0% (v/v) PEDOT: PSS were fabricated using a thermal reverse casting method where low melting agarose served as the pore template. Sample characterizations were performed by means of scanning electron microscopy (SEM), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), X-ray diffraction analysis (XRD) and electrochemical impedance spectroscopy (EIS). Our results showed enhanced electrical conductivity of the cs-gel-agar hydrogels when mixed with DMSO-doped PEDOT: PSS wherein the optimum mixing ratio was observed at 1% (v/v) with a conductivity value of 3.35 × 10−4 S cm−1. However, increasing the PEDOT: PSS content up to 1.5 % (v/v) resulted in reduced conductivity to 3.28 × 10−4 S cm−1. We conducted in vitro stability tests on the porous hydrogels using phosphate-buffered saline (PBS) solution and investigated the hydrogels’ performances through physical observations and ATR–FTIR characterization. The present study provides promising preliminary data on the potential use of Cs-Gel-Agar-based PEDOT: PSS hydrogel for tissue engineering, and these, hence, warrant further investigation to assess their capability as biocompatible scaffolds.

Pyrolysis of Lemon Peel Waste in a Fixed-bed Reactor and Characterization of Innovative Pyrolytic Products

The pyrolysis of LPW was carried out in a laboratory fixed-bed reactor at final temperature of 300°C, 400°C and 500°C with an incremental heating rate of 10°C/min, under N2 atmosphere. The maximum yields of bio-oil, biochar and gas were 16.66 wt.% (at 400°C), 66.89 wt.% (300°C) and 54.6 wt.% (500°C), respectively. The recovered biochar FTIR characterization reveals that it is a promising precursor to produce carbon materials, biofertilizer and for solid fuel applications. The bio-oil chemical characterization (GC-MS and FTIR analyzes) shows its richness with innovative compounds such as squalene, d-limonene, ß-Sitosterol and phenol, suitable for applications agriculture, biochemical and pharmaceutical industries. The pyrolytic oil presents also good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels. The recovered pyrolytic gas has a maximum calorific value around 12 MJ/kg with an average composition of CO (up to 75.87 vol.%), of CH4 (up to 5.25 vol.%) and of CnHm (up to 1.48 vol.%). The results could be applied by citrus farmers and agri-food industrials for large scale application to ensure a sustainable waste management of their citrus by-products and to guarantee economic benefits.