scholarly journals EKSTRUKSI DAN KARAKTERISASI FILAMEN KOMPOSIT POLYLACTID ACID (PLA) / CARBON NANO TUBE (CNT)

2021 ◽  
Vol 2 (2) ◽  
pp. 12
Author(s):  
Dicky Oktavian ◽  
Budi Arifvianto ◽  
Muslim Mahardika
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Additive Manufacturing ◽  
Fused Deposition Modelling ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Carbon Nano Tube ◽  
Scanning Electron

Dewasa ini teknologi additive manufacturing (AM) mengalami perkembangan yang pesat. Salah satu metode additive manufacturing yang saat ini populer di berbagai belahan dunia adalah metode fused deposition modelling. Prinsip kerja metode ini adalah dengan cara mengekstrusi material filamen polimer yang meleleh dan sudah melewati temperatur rekristalisasinya melalui sebuah nozzle, kemudian produk akan terbentuk secara lapis demi lapis yang dibentuk melalui gerakan relatif dari meja mesin. Dalam pengaplikasiannya, material filamen dapat dibuat dalam bentuk komposit sehingga diperoleh sifat-sifat unik tertentu sehingga dapat digunakan pada bidang-bidang tertentu. Salah satunya adalah pada bidang kesehatan, sebagai pembuatan implan atau jaringan tubuh dengan memiliki kekuatan yang tinggi dan bersifat biodegradable. Pada penelitian ini, dilakukan pembuatan filamen komposit PLA-CNT dengan metode ekstrusi. Proses ekstrusi dilakukan dengan variasi temperatur 143, 145, dan 147ºC dengan memberi tambahan polyethylene glycol (PEG) sebagai plasticizer untuk meningkatkan fleksibilitas dan workability. Hasil pengamatan dengan scanning electron microscope (SEM) mengindikasikan bahwa proses ekstrusi berjalan kurang stabil karena terdapat tekstur permukaan yang bergelombang. Dari pengujian karakterisasi differential scanning calorimetry (DSC), derajat kristalinitas pada variasi ekstrusi filamen PLA-CNT mengalami peningkatan seiring meningkatnya temperatur ekstrusi. Pada pengujian karakterisasi fourier transform infrared spectroscopy (FTIR) terdapat perubahan komposisi kimia pada filamen yang signifikan, yang juga sejalan dengan degradasi sifat mekanis. Variasi filamen dengan temperatur ekstrusi 147ºC memiliki nilai kekerasan paling tinggi yaitu sebesar 40,50 MPa.

Surface Modification of Magnesium Hydroxide with Stearic Acid

2012 ◽  
Vol 602-604 ◽  
pp. 1693-1699 ◽  
Author(s):  
Dong Sheng Zhang ◽  
Zhi Qi Liu ◽  
Li Juan Li ◽  
Li Xia Zhu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Surface Modification ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Stearic Acid ◽  
Magnesium Hydroxide ◽  
Esterification Reaction ◽  
Scanning Calorimetry ◽  
Scanning Electron

The surface of magnesium hydroxide (MH) was modified with stearic acid (SA). The modification mechanism was analyzed using a scanning electron microscope, thermogravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The results showed that an esterification reaction occurred between SA and MH. The modification effect was evaluated by activation index and oil absorbance rate. The results indicated that the optimum technological conditions were as follows: SA dosage was 1.25 wt. % at 70 °C for 10 min at a stirring rate of 2000 rpm. As a result, both dispersion and hydrophobicity of modified MH were remarkably improved.

scholarly journals FORMULATION AND EVALUATION OF PECTIN-CALCIUM CHLORIDE BEADS OF AZATHIOPRINE FOR COLON TARGETED DRUG DELIVERY SYSTEM

2018 ◽  
Vol 10 (1) ◽  
pp. 172 ◽  
Author(s):  
Samir A Atara ◽  
Moinuddin M Soniwala
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Scanning Calorimetry ◽  
Eudragit S100 ◽  
Calcium Pectinate ◽  
Scanning Electron

Objective: Calcium pectinate is an insoluble hydrophilic material used for sustained release delivery. The objective of the study was formulation and evaluation pectin-calcium chloride beads of azathioprine.Methods: Calibration curves of azathioprine were prepared in 0.1N HCl solution (pH-1.2) and phosphate buffer (pH-6.8 and pH-7.4). Fourier transform infrared spectroscopy and differential scanning calorimetry was used to determine compatibility between azathioprine and excipients. Formulation and optimization of calcium-pectinate beads were performed. The coating of the optimized batch was performed with eudragit S100. Micrometric properties, scanning electron microscopy, in vitro azathioprine release, and stability study was performed. Dissolution kinetic study was assessed for various kinetics models of the optimized batch. The Wilcoxon test followed by the Dunnett’s multiple comparison tests were performed between uncoated and coated beads in vitro dissolution profile of optimized batch in 0.1N HCl after 2 h.Results: Fourier transform infrared spectroscopy and differential scanning calorimetry had identical peaks with that of pure azathioprine in compatibility study. Scanning electron microscopy of an uncoated optimized batch of beads indicated the smooth and uniform surface of prepared beads. Eudragit S100 coating was decreased release of azathioprine release in 0.1N HCl after 2 h (p = 0.049, q = 3.533). Korsmeyer/Peppa's model was applied with release exponent higher than 1. In vitro percentage cumulative azathioprine release was identical before and after stability study.Conclusion: Calcium pectinate beads of azathioprine, a multi-particulate dosage form using pH-dependent approaches were prepared.

scholarly journals Processing of (Co)Poly(2-oxazoline)s by Electrospinning and Extrusion from Melt and the Postprocessing Properties of the (Co)Polymers

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 295 ◽  
Author(s):  
Wojciech Wałach ◽  
Natalia Oleszko-Torbus ◽  
Alicja Utrata-Wesołek ◽  
Marcelina Bochenek ◽  
Ewa Kijeńska-Gawrońska ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Molar Mass ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Gradient Copolymers ◽  
Fused Deposition

Poly(2-oxazoline) (POx) matrices in the form of non-woven fibrous mats and three-dimensional moulds were obtained by electrospinning and fused deposition modelling (FDM), respectively. To obtain these materials, poly(2-isopropyl-2-oxazoline) (PiPrOx) and gradient copolymers of 2-isopropyl- with 2-n-propyl-2-oxazoline (P(iPrOx-nPrOx)), with relatively low molar masses and low dispersity values, were processed. The conditions for the electrospinning of POx were optimised for both water and the organic solvent. Also, the FDM conditions for the fabrication of POx multi-layer moulds of cylindrical or cubical shape were optimised. The properties of the POx after electrospinning and extrusion from melt were determined. The molar mass of all (co)poly(2-oxazoline)s did not change after electrospinning. Also, FDM did not influence the molar masses of the (co)polymers; however, the long processing of the material caused degradation and an increase in molar mass dispersity. The thermal properties changed significantly after processing of POx what was monitored by increase in enthalpy of exo- and endothermic peaks in differential scanning calorimetry (DSC) curve. The influence of the processing conditions on the structure and properties of the final material were evaluated having in a mind their potential application as scaffolds.

scholarly journals Calorimetric study on Bi-Cu-Sn alloys

2019 ◽  
Vol 38 (2019) ◽  
pp. 541-546
Author(s):  
Jolanta Romanowska
Keyword(s):  
Differential Scanning Calorimetry ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Temperature Interval ◽  
Energy Dispersive Spectrometer ◽  
Energy Dispersive ◽  
Calorimetric Study ◽  
Calorimetric Investigation ◽  
Scanning Calorimetry ◽  
Scanning Electron

AbstractThe paper presents results of calorimetric investigation of the Bi-Cu-Sn system by means of differential scanning calorimetry (DSC) at the temperature interval 25-1250∘C, Values of liquidus, solidus and invariant reactions temperatures, as well as melting enthalpies of the selected alloys were determined. Microstructure investigation of the alloys were performed by the use of a scanning electron microscope (SEM) equipped with an energy-dispersive spectrometer (EDS).

scholarly journals New insight into single phase formation of capric acid/menthol eutectic mixtures by Fourier-transform infrared spectroscopy and differential scanning calorimetry

2020 ◽  
Vol 19 (2) ◽  
pp. 361-369 ◽  
Author(s):  
Hiba H. Ali ◽  
Mowafaq M. Ghareeb ◽  
Mayyas Al-Remawi ◽  
Faisal T. Al-Akayleh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Hydrogen Bond ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Bond Formation ◽  
Capric Acid ◽  
Fourier Transform Infrared ◽  
Scanning Calorimetry ◽  
Hydrogen Bond Formation

Purpose: To examine the structural changes of a eutectic mixture comprising capric acid and menthol which are commonly used in pharmaceutical applications. Methods: A phase diagram was constructed by quantitative mixing of capric acid and menthol under controlled conditions until a single liquid phase was formed. Eutectic mixtures of capric acid: menthol at the ratios of 3:2, 1:4, 1:1, 2:3, and 1:4 were prepared. Hydrogen bond formation and conformational changes were analyzed using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Microscopic imaging was carried out to capture phase change events upon increasing temperature. Results: Menthol confirmed the intact structure of a hexagonal ring. The high degree of broadening of the menthol O-H groups indicates hydrogen bond formation. FTIR band changes related to capric acid suggest a break-up of the methylene arrangement structure due to changes in the C-H band frequencies. The red shift encountered in C=O stretching band emphasizes hydrogen bond formation taking place between the oxygen atom of the hydroxyl group comprising the carboxylic moiety of capric acid and the hydrogen atom of menthol hydroxyl group. DSC results indicate the presence of two polymorphs of the capric acid/ menthol complex. Both exhibited crystallization and conformational change exotherms in addition to two melting endotherms as result of transformation of crystalline components to become partially crystalline due to hydrogen bond formation. Conclusion: The interaction between capric acid and menthol results in a typical preparation of deep eutectic systems that can act as natural-based solvents in numerous pharmaceutical applications. Keywords: Eutectic system, Capric acid, Menthol, Differential scanning calorimetry, DSC, Fourier transform infrared spectroscopy, FTIR

RETRACTED: Fabrication of Poly(Lactic Acid) Nanofibers by Cotton Candy Method

2017 ◽  
Vol 728 ◽  
pp. 193-198
Author(s):  
Rutchaneekorn Wongpajan ◽  
Supaphorn Thumsorn ◽  
Hiroyuki Inoya ◽  
Masayuki Okoshi ◽  
Hiroyuki Hamada
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Electron Microscope ◽  
Air Pressure ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
Cotton Candy ◽  
Nozzle Temperature ◽  
Scanning Electron

The poly (lactic acid) (PLA) fiber of biodegradable polymer was fabricated by cotton candy method with small nozzle. The air pressure was varied from 0.2-0.5 MPa with nozzle temperature of 210-260°C. The morphology of fiber was determined by scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). SEM results suggested that diameters the PLA fiber at temperature 250°C and air pressure of 0.2 MPa were smaller than the fiber at low and high temperature. The sizes of the fibers were lower than 1 μm and the fibers were irregular size. Crystallinity significantly decreased when increasing barrel temperatures while it slightly changed when varied air pressure. The productivity of PLA fibers was around 30-180 g/h depended on controlled the nozzle temperature and the air pressure.

ENHANCED CALCIUM PHOSPHATE PRECIPITATION ON THE SURFACE OF Mg-ION-IMPLANTED ZrO2 BIOCERAMIC

2007 ◽  
Vol 14 (01) ◽  
pp. 71-77 ◽  
Author(s):  
H. LIANG ◽  
Y. HUANG ◽  
F. HE ◽  
H. F. DING ◽  
Y. Z. WAN
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Electron Microscope ◽  
Calcium Phosphate ◽  
Body Fluid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Phosphate Precipitation ◽  
Scanning Electron ◽  
Ion Implanted

Modification of bioceramics by ion implantation of magnesium ( Mg ) is of interest as Mg is the fourth abundant cation in the human body. In this work, magnesium was ion-implanted into a ZrO 2 based bioceramic stabilized with Y 2 O 3 and Al 2 O 3. Both Mg -implanted and unimplanted samples were soaked in a simulated body fluid (SBF) for a period of time. The deposits on the surface of various samples were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). We find that the Mg -implanted ZrO 2 shows better bioactivity than the plain bioceramic. These results indicate that Mg -implantation can improve the bioactivity of the ZrO 2 based bioceramic. Mechanisms governing the improvement are discussed in this paper.

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