scholarly journals Synthesis and Characterization of Novel Hybrid Flocculants Based on Potato Starch Copolymers with Hollow Carbon Spheres

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1498
Author(s):  
Beata Schmidt ◽  
Krzysztof Kowalczyk ◽  
Beata Zielinska
Keyword(s):  
Laser Scanning ◽  
Potato Starch ◽  
Particle Size Analysis ◽  
Laser Scanning Microscopy ◽  
Molar Ratio ◽  
Size Analysis ◽  
Carbon Spheres ◽  
Scanning Calorimetry ◽  
Kaolin Suspension ◽  
Flocculation Efficiency

Novel carbon nanofiller-based starch-g-polyacrylamide hybrid flocculation materials (St-PAM-CS) were in situ prepared using potato starch (St), acrylamide (AM), and hollow mesoporous carbon spheres (CSs; diameters of 300–400 nm). Structures of different St-PAM-CS systems were characterized by Fourier transform infrared (FTIR) spectroscopy, X-Ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser scanning microscopy (LSM), and particle size analysis. The flocculation tests were evaluated by removing high turbidity kaolin suspension—initial absorbance 1.84. The effect of the St to AM molar ratio, doses, and content of CSs in hybrids on flocculation efficiency were examined. Satisfactory flocculation efficiency was obtained for all hybrids with 1 wt.% of the CS component. The highest reduction of the kaolin suspension absorbance (to 0.06) was observed for a 3 mL dose of the starch hybrid with the highest AM content. Additionally, St-PAM-CS showed a reduction in the sludge volume in time. The hybrids reached better flocculation efficiency in relation to the reference systems without CSs. The proposed flocculation mechanism (considering bridging, patching, and formation of hydrogen bonds) has been confirmed by the recorded results.

scholarly journals Preparation and Characterization of Potato Starch Copolymers with a High Natural Polymer Content for the Removal of Cu(II) and Fe(III) from Solutions

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2562
Author(s):  
Beata Schmidt ◽  
Joanna Rokicka ◽  
Jolanta Janik ◽  
Katarzyna Wilpiszewska
Keyword(s):  
Laser Scanning ◽  
Treatment Time ◽  
Potato Starch ◽  
Polymer Network ◽  
Laser Scanning Microscopy ◽  
Material Structure ◽  
Adsorption Efficiency ◽  
Natural Polymer ◽  
Scanning Calorimetry ◽  
Adsorption Mechanisms

Cross-linked potato starch (StMBA) and starch-g-polyacrylamide materials with a high content of natural polymer from 60 to 90 wt.% (St60–St90) were synthesized by double chemical-chemical modification (grafting and cross-linking). Eco-friendly starch absorbents were tested for removal of Cu2+ and Fe3+ from aqueous solutions. The characteristics of the obtained materials (Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermal analysis (TGA), X-Ray Diffraction (XRD) and laser scanning microscopy (LSM)) confirmed their diversity in terms of composition and structure. The effect of N,N’-Methylenebisacrylamide (MBA) and polyacrylamide (PAM) content in the starch graft copolymers, treatment time and concentration of metal ions on adsorption efficiency were investigated. The adsorption efficiency for StMBA was 14.0 mg Cu2+/g and 2.9 mg Fe3+/g, regardless of the initial concentration of ions, whereas for starch graft copolymer St60 it was 23.0 mg Cu2+/g and 21.2 mg Fe3+/g. Absorption of Fe(III) was persisted even after 2 days. Pseudo-second order model was used to investigate the adsorption mechanisms. It was found that in addition to the chemical adsorption of ions on the surface, there is sorption inside the polymer network and chelating mechanism may dominate. Satisfactory results were attributed to the adequate grafting of PAM onto starch, the ability to form complexes with metal cations and changes in material structure.

Electroporation-enhanced entrapment of diclofenac sodium and ascorbic acid into DPPC liposomes

2021 ◽  
Vol 16 (11) ◽  
pp. 19-26
Author(s):  
Heba M. Fahmy ◽  
Amani M.R. Idris ◽  
Anwar A. Elsayed ◽  
Ebtesam A. Mohamad
Keyword(s):  
Ascorbic Acid ◽  
Rhodamine B ◽  
Laser Scanning ◽  
High Efficiency ◽  
Diclofenac Sodium ◽  
Particle Size Analysis ◽  
Physical Characteristics ◽  
Laser Scanning Microscopy ◽  
Size Analysis ◽  
Confocal Laser

The effect of electroporation on the physical characteristics of 1,2-dipalmitoyl-Sn-glycerol-3- phosphocholine (DPPC) liposome loading diclofenac sodium, ascorbic acid and Rhodamine B was studied. Group one liposomes were incubated with diclofenac sodium, group two liposomes were incubated with ascorbic acid and group three: liposomes were incubated with Rhodamine B. The three groups were subjected to electroporation protocol. Samples were exposed to different field strengths at pulses 30, 60 and 90 pulses respectively with pulse duration 4 milliseconds. After electroporation, liposomes were separated from unentrapped drugs and form the dye through centrifugation. Physical characteristics of liposomes were examined using Transmission electron microscope (TEM), Confocal laser scanning microscopy (CLSM) and particle size analysis. Liposomes are entrapping ascorbic acid with high efficiency at the values of 900 V/0.2 cm with 60 pulses, 800 and 1000 V/ 0.2 cm at 90 pulses. Diclofenac sodium was entrapped at 800 V/0.2 cm and 90 pulses. Rhodamine B was entrapped at 500 and 1000 V/0.2 cm at 30 pulses. Based on the present results, entrapping of diclofenac sodium and ascorbic acid into liposomes can be controlled efficiently by electroporation technique. Optimum entrapping occurred at 800 V/0.2 cm and 90 pulses for ascorbic acid and DS at 900 V/0.2 cm and 30 pulses for Rh-B.

scholarly journals Effect of dissolution rate and subsequent ion release on cytocompatibility properties of borophosphate glasses

2019 ◽  
Vol 5 (1) ◽  
pp. 85-97
Author(s):  
Nusrat Sharmin ◽  
Mohammad S. Hasan ◽  
Md. Towhidul Islam ◽  
Chengheng Pang ◽  
Fu Gu ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ion Release ◽  
Scanning Calorimetry ◽  
Cell Culture Study ◽  
Borophosphate Glasses ◽  
Mg63 Cells

AbstractPresent work explores the relationship between the composition, dissolution rate, ion release and cytocompatibility of a series of borophosphate glasses. While, the base glass was selected to be 40mol%P2O5-16mol%CaO-24mol%MgO-20mol%Na2O, three B2O3 modified glass compositions were formulated by replacing Na2O with 1, 5 and 10 mol% B2O3. Ion release study was conducted using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The thermal scans of the glasses as determined by differential scanning calorimetry (DSC) revealed an increment in the thermal properties with increasing B2O3 content in the glasses. On the other hand, the dissolution rate of the glasses decreased with increasing B2O3 content. To identify the effect of boron ion release on the cytocompatibility properties of the glasses, MG63 cells were cultured on the surface of the glass discs. The in vitro cell culture study suggested that glasses with 5 mol% B2O3 (P40B5) showed better cell proliferation and metabolic activity as compares to the glasses with 10 mol% (P40B10) or with no B2O3 (P40B0). The confocal laser scanning microscopy (CLSM) images of live/dead stained MG63 cells attached to the surface of the glasses also revealed that the number of dead cells attached to P40B5 glasses were significantly lower than both P40B0 and P40B10 glasses.

scholarly journals Development of a Solid Dispersion of Nystatin with Maltodextrin as a Carrier Agent: Improvements in Antifungal Efficacy against Candida spp. Biofilm Infections

2021 ◽  
Vol 14 (5) ◽  
pp. 397
Author(s):  
Carlos Benavent ◽  
Carlos Torrado-Salmerón ◽  
Santiago Torrado-Santiago
Keyword(s):  
Antifungal Activity ◽  
Solid Dispersions ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Candida Spp ◽  
Microbiological Techniques ◽  
Characterization Studies ◽  
Candida Albicans Biofilms

The aim of this study was to improve the treatment of Candida albicans biofilms through the use of nystatin solid dispersions developed using maltodextrins as a hyperosmotic carrier. Characterization studies by differential scanning calorimetry, X-ray diffraction, dissolution studies, and particle size analysis were performed to evaluate changes in nystatin crystallinity. Antifungal activity and anti-biofilm efficacy were assessed by microbiological techniques. The results for nystatin solid dispersions showed that the enhancement of antifungal activity may be related to the high proportions of maltodextrins. Anti-biofilm assays showed a significant reduction (more than 80%) on biofilm formation with SD-N:MD [1:6] compared to the nystatin reference suspension. The elaboration process and physicochemical properties of SD-N:MD [1:6] could be a promising strategy for treatment of Candida biofilms.

Preparing poly styrene-co-acrylic acid and recycled waste magnetite composite from concrete industry as a printing ink

2020 ◽  
pp. 089270572096215
Author(s):  
Maryam Ataeefard ◽  
Mohammad Mahdi Salehi
Keyword(s):  
Polymeric Composite ◽  
Particle Size Analysis ◽  
Control Agent ◽  
Main Element ◽  
Size Analysis ◽  
Gradient Force ◽  
Scanning Calorimetry ◽  
Environmental Aspect ◽  
X Ray ◽  
Recycled Waste

The main element of electrophotographic (EP) printing and copying devices is a polymeric composite called toner and one of the most significant components of toner composite is an iron oxide (magnetite). Magnetite, which is applied as a colorant and additive for toner is the main mineral able to develop an electrical charge on the printing procedure. Although there are several ways to produce magnetite, given the dearth of resources and environmental aspect, it is safer to practice recycling and greener method. In the present study, an encouraging way to reuse the magnetite particles as a byproduct of the preparation of micro silica in the concrete industry was described. The obtained magnetite was then utilized as the charge control agent to produce magnetite/carbon black/styrene co-butyl acrylate composite microspheres by green emulsion aggregation method, which is used as toner in the printing procedure. Characterization of toner and recovered magnetite was done by X-ray Powder Diffraction (XRD), Atomic Gradient Force Magnetometry (AGFM), Particle Size Analysis (PSA), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM-EDX). The results supported the fact that the produced toner composite by recycled waste magnetite show suitable characteristics comparing to an industrial toner.

Synthesis and Characterization of Polyimide/Silica Nanocomposites

2011 ◽  
Vol 311-313 ◽  
pp. 96-100
Author(s):  
Jian Li Cheng ◽  
Cun Zhou ◽  
Hao Peng ◽  
Huan Wang ◽  
Yu Sun
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Amic Acid ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Size Of Particles

Two kind of polyimide/silica nanocomposites which were recorded poly(amic acid)/ silica(PAA/SiO2) and SiO2in poly(amic acid) ammonium salt(PAS/SiO2) respectively, have been prepared for different methods. The size of SiO2in PAA/SiO2and PAS/SiO2are measured by Particle size analysis and the average particle size are 377nm and 53.7nm. Transmission electron microscopy(TEM) images of PAS/ SiO2confirm that the size of particles are ranged from 40 to 80nm. The stuctures of samples have been characterized by FT-IR spectra. The thermal stability of PAA/SiO2and PAS/SiO2are studied by thermogravimetric analysis (TGA) and the thermal behaviors were investigated by differential scanning calorimetry (DSC) in this paper. It is shown that PAA/SiO2have slightly better thermal properties than that of PAS/SiO2. The results obtained from Instron universal strength tester present the water-solube PAS/SiO2own the excellent mechanical prperties as same as PAA/SiO2.

Synthesis and Characterization Investigations of Laboratory-Synthesized VB-VB2-V3B4 Reinforced Al-7wt.% Si Composites via Mechanical Alloying and Pressureless Sintering

2017 ◽  
Vol 263 ◽  
pp. 189-194
Author(s):  
Sıddıka Mertdinç ◽  
Emre Tekoğlu ◽  
Hasan Gökçe ◽  
Duygu Ağaoğulları ◽  
M. Lütfi Öveçoğlu
Keyword(s):  
Particle Size ◽  
Wear Rate ◽  
Mechanical Alloying ◽  
Weight Ratio ◽  
Sintered Sample ◽  
Optical Microscope ◽  
Particle Size Analysis ◽  
Hydraulic Press ◽  
Size Analysis ◽  
Scanning Calorimetry

In this study, the effect of mechanical alloying (MA) on the microstructural, mechanical and physical properties of vanadium boride particulate reinforced Al-7 wt. % Si matrix composites were investigated. VB-VB2-V3B4 containing vanadium boride hybrid powders were mechanochemically synthesized for 5 h from the V2O5-B2O3-Mg powder blends and leached with hydrochloric acid (HCl) for purification. Laboratory-synthesized VB-VB2-V3B4 powders were incorporated into the Al-7wt. % Si matrix powders with the amount of 2 wt.% via MA for 4h in a SpexTM Mixer/Mill using hardened steel vial/balls with a ball-to-powder weight ratio of 7/1. After the MA process, phase analysis (X-ray diffraction), particle size analysis (laser particle size measurement), surface area analysis (Brunauer-Emmett-Teller measurement) and microstructural characterization (scanning electron microscope (SEM) micrograph) and thermal analysis (differential scanning calorimetry (DSC)) of the non-milled/milled Al-7 wt.% Si-2wt.% (VB-VB2-V3B4) powders were conducted. As-blended and MA’d powders were compacted at a uniaxial hydraulic press to obtain cylindrical compacts with a diameter of 12 mm under a pressure of 400 MPa. Green bodies were sintered at 570°C for 2 h under Ar gas flowing conditions. Microstructural characterizations of the sintered samples were carried out using XRD and optical microscope (OM). Physical and mechanical properties of the composites were investigated in terms of density (Archimedes method), Vickers microhardness and wear rate. The microhardness and wear rate of the 4h of MA’d and sintered sample respectively increased to 0.865±0.256 GPa and 0.0036 mm3/N.m as compared with those of as-blended and sintered sample.

scholarly journals Study on characteristics, properties, and morphology of poly(lactic acid)/chitosan/hydroquinine green nanoparticles

2018 ◽  
Vol 7 (5) ◽  
pp. 417-423
Author(s):  
Nguyen Thi Thu Trang ◽  
Tran Thi Mai ◽  
Nguyen Vu Giang ◽  
Tran Huu Trung ◽  
Do Van Cong ◽  
...  
Keyword(s):  
Particle Size ◽  
Lactic Acid ◽  
Particle Size Analysis ◽  
Poly Lactic Acid ◽  
Size Analysis ◽  
Linear Regression Coefficient ◽  
Scanning Calorimetry ◽  
Calibration Equation ◽  
Basic Particle ◽  
Fast Release

Abstract Poly(lactic acid)/chitosan (PLA/CS) green nanoparticles containing hydroquinine (Hq) were prepared by emulsion method. The content of Hq was 10–50 wt% compared with the weight total of PLA and CS. The characteristics of these nanoparticles were analyzed by Fourier transform infrared (FTIR), differential scanning calorimetry, field emission scanning electron microscopy (FESEM), and particle size analysis. The wavenumbers of C=O, C=N, OH, and CH3 groups in FTIR spectra of the PLA/CS/Hq (PCHq) nanoparticles shifted in comparision with neat PLA, CS, and Hq that proved the interaction between these components. The FESEM images and particle size analysis results showed that the basic particle size of PCHq nanoparticles ranged between 100 and 200 nm. The Hq released from PLA/CS nanoparticles in pH 2 and pH 7.4 solutions was determined by ultraviolet-visible method. The obtained results indicated that the linear regression coefficient of calibration equation of Hq in the above solutions approximates 1. The Hq release from the PCHq nanoparticles includes fast release for the eight first testing hours, and then, controlled slow release. The Hq released process was obeyed according to the Korsmeyer-Peppas kinetic model.

Wollastonite hybridizing stearic acid as thermal energy storage material

2014 ◽  
Vol 07 (06) ◽  
pp. 1440011 ◽  
Author(s):  
Dawei Xu ◽  
Huaming Yang
Keyword(s):  
Energy Storage ◽  
Stearic Acid ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Particle Size Analysis ◽  
Vacuum Impregnation ◽  
Size Analysis ◽  
Stable Phase ◽  
Scanning Calorimetry ◽  
Thermal Energy Storage Material

This paper reported on the preparation of a novel stearic acid (SA)/wollastonite (W) composite as a form-stable phase change material (PCM) for thermal energy-storage (TES) by vacuum impregnation, and especially investigated the effect of the size grade of W on the thermal properties of the SA/W composite. Samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle-size analysis, and differential scanning calorimetry (DSC). Natural W (Wr) was classified into four size grades by wet screening. The results indicate that no chemical reaction took place between SA and W, and the SA load in the SA/W composite increased with an increase in the length/diameter (L/D) ratio of the W. The SA/W composite with a W L/D ratio of 22.5 exhibited latent heats of melting and freezing of 58.64 J/g and 56.95 J/g, respectively, which was higher than those of the composite incorporating natural W. We believe that the as-prepared form-stable PCM composite could provide a potential means of TES for the concentrated solar power.

Synthesis and Characterization of MgFe2O4 /MgO Composite Films from Layered Double Hydroxides Precursors

2013 ◽  
Vol 690-693 ◽  
pp. 342-350
Author(s):  
Ying Chao Zhang ◽  
Ting Ting Chen ◽  
Lan Yang
Keyword(s):  
Magnetic Properties ◽  
Composite Films ◽  
Xrd Analysis ◽  
Particle Size Analysis ◽  
Molar Ratio ◽  
Size Analysis ◽  
X Ray ◽  
Single Source Precursor ◽  
Double Hydroxide ◽  
Double Hydroxides

MgFe2O4/MgO composite films have been successfully fabricated by a facile route using magnesium iron layered double hydroxide (MgFe-LDH) as a single-source precursor. This strategy mainly involves the formation of MgFe-LDH film by casting the slurry of MgFe-LDH precursor on the α-Al2O3substrate, followed by calcination at 900°C. The structure, morphology and magnetic properties of the resulting films were characterized by means of X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), laser particle size analysis, scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and vibrating sample magnetometer (VSM). The results show that the composite films are composed of spherical or elliptical grains with diameters of less than 150nm and their thickness range was 2~3 μm. EDX mapping analysis reveals that the composite films have uniform distribution of MgFe2O4particles in MgO matrix. Further investigation indicates that the magnetic properties of the composite films can be tailored by altering the Mg/Fe molar ratio of LDH precursors.

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