scholarly journals Karakteristik Membran Komposit Polietersulfon, Polivinilpirolidon dan Kitosan

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Muhammad Fadli ◽  
Al Khausar ◽  
Sofyana Sofyana ◽  
Ummi Fathanah
Keyword(s):  
Mechanical Properties ◽  
Phase Inversion ◽  
Functional Group ◽  
Permeability Test ◽  
Nanofiltration Membranes ◽  
Absorption Bands ◽  
Swelling Degree ◽  
Phase Inversion Technique ◽  
Pes Membrane ◽  
Sem Test

Polyethersulfone (PES) is a membrane forming material that has many advantages but is hydrophobic, so it is necessary to add other materials, such as composite PES with Polyvinylpyrrolidone (PVP) and chitosan. The addition of PVP aims to change the nature of the PES membrane to be hydrophilic and the addition of chitosan aims to improve the mechanical properties of the polymer. The purpose of this study was to study the effect of adding PVP and chitosan to the characteristics of PES membranes. The membranes were made using a phase inversion technique by immersion precipitation with a concentration of 20% PES, 1% PVP, and chitosan were varied, namely 0% (M0 membrane), 1.5% (M1), 2% (M2), and 3% (M3). The results of the permeability test showed that the membranes M0, M1, M2, and M3 are classified as nanofiltration membranes with Lp values of 9.1237, 7.618, 6.9651, and 4.4077 L/m2.h.bar. The swelling degree value is 61,512; 103.111; 145,564; and 158.610% and the overall porosity value is 22.892; 32.360; 80.726; and 117.016%. The SEM test showed that the morphology of the membrane changed its structure as the concentration of chitosan increased. The FTIR test on the membrane showed that there were absorption bands, each of which identified its functional group.

scholarly journals Cylindrical Polyurethane Scaffold Fabricated Using the Phase Inversion Method: Influence of Process Parameters on Scaffolds’ Morphology and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2977
Author(s):  
Aleksandra Kuźmińska ◽  
Dominika Kwarta ◽  
Tomasz Ciach ◽  
Beata A. Butruk-Raszeja
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Polymer Solution ◽  
Process Parameters ◽  
Phase Inversion ◽  
Young Modulus ◽  
Process Time ◽  
Inversion Method ◽  
Influence Of Process Parameters ◽  
Phase Inversion Technique

This work presents a method of obtaining cylindrical polymer structures with a given diameter (approx. 5 mm) using the phase inversion technique. As part of the work, the influence of process parameters (polymer hardness, polymer solution concentration, the composition of the non-solvent solution, process time) on the scaffolds’ morphology was investigated. Additionally, the influence of the addition of porogen on the scaffold’s mechanical properties was analyzed. It has been shown that the use of a 20% polymer solution of medium hardness (ChronoFlex C45D) and carrying out the process for 24 h in 0:100 water/ethanol leads to the achievement of repeatable structures with adequate flexibility. Among the three types of porogens tested (NaCl, hexane, polyvinyl alcohol), the most favorable results were obtained for 10% polyvinyl alcohol (PVA). The addition of PVA increases the range of pore diameters and the value of the mean pore diameter (9.6 ± 3.2 vs. 15.2 ± 6.4) while reducing the elasticity of the structure (Young modulus = 3.6 ± 1.5 MPa vs. 9.7 ± 4.3 MPa).

scholarly journals REMOVAL OF CD2+ AND PB2+ HEAVY METALS IN WATER BY USING ADSORPTION-ULTRAFILTRATION HYBRID PROCESS

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Sri Mulyati ◽  
Syawaliah Syawaliah
Keyword(s):  
Heavy Metals ◽  
Phase Inversion ◽  
Membrane Filtration ◽  
Adsorption Process ◽  
Final Concentration ◽  
Long Period ◽  
Phase Inversion Technique ◽  
Pes Membrane ◽  
Cadmium And Lead ◽  
Adsorbent Dose

Pollution caused by heavy metals is a serious problem for the environment. Cadmium and Lead are heavy metals that are highly toxic to living beings. These metals are non-biodegradable and remain in the environment for a long period of time. The removal process of these heavy metals with adsorption using Aceh natural zeolite followed by the membrane filtration has been conducted. Operating parameters such as contact time, sample pH and adsorbent dose found to affect the removal efficiency in the adsorption process. PES membrane which prepared by phase inversion technique was used to eliminate the residual heavy metals remained in the effluent of adsorption process. The final concentration after removal with both processess was 0.21 mg/L and 0.242 mg/L for Cd2+ and Pb2+, respectively. Although the concentration are still above the permitted threshold, which is no more than 0.005 mg/L for Cd2+ and 0.01 mg/L at maximum for Pb2+, this combination can however still be an alternative that can be employed to remove heavy metals in water.

PEEKWC Capsules Prepared by Phase Inversion Technique: A Morphological and Dimensional Study

2007 ◽  
Vol 42 (13) ◽  
pp. 2809-2827 ◽  
Author(s):  
A. Figoli ◽  
G. De Luca ◽  
E. Longavita ◽  
E. Drioli
Keyword(s):  
Phase Inversion ◽  
Inversion Technique ◽  
Phase Inversion Technique

PROTEIN INFLUENCE ON THE MECHANICAL PROPERTIES OF NR

2021 ◽  
Author(s):  
Yayoi Akahori ◽  
Misao Hiza ◽  
Soki Yamaguchi ◽  
Seiichi Kawahara
Keyword(s):  
Mechanical Properties ◽  
Nmr Spectroscopy ◽  
Sodium Dodecyl Sulfate ◽  
Carbon Black ◽  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Sodium Dodecyl ◽  
Swelling Degree ◽  
Deproteinized Natural Rubber ◽  
Rubber State

ABSTRACT Protein effect on vulcanization of NR, obtained from Hevea brasiliensis, was investigated by analyzing the crosslinking structure of the resulting vulcanizates prepared from untreated NR, deproteinized natural rubber (DPNR), and protein-free natural rubber (PFNR) by swelling methods and rubber-state NMR spectroscopy. The proteins present in NR were removed by three methods: deproteinization with enzyme, urea, or urea–acetone in the presence of sodium dodecyl sulfate. The amount of proteins present in NR, approximately 0.238 w/w%, was reduced to 0.000 w/w% by urea–acetone deproteinization, whereas it was reduced to approximately 0.003 and 0.019 w/w% by enzyme and urea deproteinizations, respectively. Hardness, swelling degree, and crosslinking structure depended on the amount of proteins. Changes in mechanical properties for the vulcanizates prepared from not only non-filler compounds but also carbon black–filled and silica-filled compounds were attributed to the amount of proteins.

scholarly journals Chitin Hydrogels Prepared at Various Lithium Chloride/N,N-Dimethylacetamide Solutions by Water Vapor-Induced Phase Inversion

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Khoa Dang Nguyen ◽  
Takaomi Kobayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Vapor ◽  
Lithium Chloride ◽  
Phase Inversion ◽  
Complex Modulus ◽  
Gel Formation ◽  
Atomic Force ◽  
Entanglement Network ◽  
Water Contents

Chitin was chemically extracted from crab shells and then dissolved in N,N-dimethylacetamide (DMAc) solvent with lithium chloride (LiCl) at 3, 5, 7, and 10%. The concentrated chitin-DMAc/LiCl solutions were used for the preparation of chitin hydrogels by water vapor-induced phase inversion at 20°C. The coagulation process was investigated while altering the concentration of LiCl in the DMAc solution. The shear viscosity of the chitin solution increased with higher LiCl amounts and decreased when the concentration of LiCl was reduced by adding water to the chitin solution, implying high LiCl concentration delayed the coagulation of chitin solution in the presence of water. The viscoelasticity of the chitin solutions indicated the gel formation intensification was dependent on the dose of LiCl and chitin in the DMAc solution. After the chitin solution was coagulated, the resultant hydrogels had water contents of 387–461% and the tensile strength varied from 285 to 400 kPa when the concentration of LiCl in the hydrogel was adjusted to 3% and 7%, respectively. As for viscoelasticity, the complex modulus of the chitin hydrogels indicated that the increment of the LiCl concentration up to 7% formed the tight hydrogels. Atomic force microscopic (AFM) image revealed the formation of the entanglement network and larger domains of the aggregated chitin segments. However, the hydrogel prepared at 10% LiCl in DMAc solution exhibited weak mechanical properties due to the loose hydrogel networking caused by the strong aggregation of the chitin segments.

Dual-layer hollow fiber MT-SOFC using lithium doped CGO electrolyte fabricated via phase-inversion technique

2017 ◽  
Vol 304 ◽  
pp. 113-125 ◽  
Author(s):  
Siti Munira Jamil ◽  
Mohd Hafiz Dzarfan Othman ◽  
Mukhlis A. Rahman ◽  
Juhana Jaafar ◽  
Mohamad Azuwa Mohamed ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Phase Inversion ◽  
Inversion Technique ◽  
Phase Inversion Technique

scholarly journals Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose–Acetate/Silica/Titania and Cellulose–Acetate/Titania Membranes

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 195 ◽  
Author(s):  
Inês Peixoto ◽  
Mónica Faria ◽  
M. Clara Gonçalves
Keyword(s):  
Cellulose Acetate ◽  
Phase Inversion ◽  
Sol Gel ◽  
Asymmetric Structure ◽  
Hydraulic Permeability ◽  
Icp Oes ◽  
Phase Inversion Technique ◽  
In Series ◽  
Covalently Bound

Two series of novel integral asymmetric monophasic hybrid membranes, cellulose acetate/silica/titania (CA/SiO2/TiO2—series 1) and cellulose acetate/titania (CA/TiO2—series 2), were developed by the coupling of sol-gel technology and a modified version of the phase inversion technique. SEM micrographs confirmed the integral asymmetric structure of all membranes. ATR-FTIR and ICP-OES results showed that, for the membranes in series 1, TiO2 is covalently bound to SiO2, which, in turn, is covalently bound to CA, while for the membranes in series 2, TiO2 is directly and covalently bound to the CA matrix. Permeation experiments revealed that the permeation performance of the membranes in series 1 is unaffected by the introduction of TiO2. In contrast, the introduction of TiO2 in the series 2 membranes increased the hydraulic permeability by a factor of at least 2 when compared to the pristine CA membrane and that incremental additions of TiO2 further increased the Lp.

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