Polymer Surface Morphology Research Articles

Extraction and studies of optoelectrical parameters of PVC/Zn0.9M0.1S (M: Co, Fe, Mn, V) films

To be used in optoelectronic applications, the nanocomposites films (doped PVC with Zn0.9M0.1S samples: M = Co, Fe, Mn, V) were prepared in this study. Casting and solid-state reaction procedures were employed to prepare PVC/CMC/Zn0.9M0.1S films. Rietveld refinement method and transmission electron microscope technique were used to investigate the structure and microstructure parameters of Zn0.9M0.1S (M: Co, Fe, Mn, V). X-ray diffraction, Fourier transform infrared and scanning electron microscope techniques were used to study the change in the structure, surface morphology and vibrational bands of PVC polymer upon doping with Zn0.9M0.1S. According to the findings, changing the type of the transition metals in Zn0.9M0.1S caused a change in the host polymer's optical characteristics. Depending on the kind of transition metals in Zn0.9M0.1S, the direct and indirect optical energy gaps of PVC/CMC/Zn0.9M0.1S are irregularly reduced. The direct/indirect optical band gaps of PVC dropped from (5.59, 5.22) eV to minimum values of (5.3, 4.27) eV as it was doped with ZnS. As Zn0.9M0.1S was incorporated into the PVC matrix, the linear and nonlinear optical parameters increased. The fluorescence intensity of pristine PVC is very weak, and it enhanced greatly as it doped with Zn0.9M0.1S. The dielectric constant (ε′), dielectric loss factor (ε″), ac conductivity (σac), the real (M′) and imaginary (M″) parts of the electric modulus changed nonmonotonically with the type of metal in Zn0.9M0.1S. Among all polymers, ′, ″ and σac revealed highest values for the PVC/Zn0.9Co0.1S and the lowest ones for PVC/Zn0.9V0.1S.

Optical and dielectric properties of PVC/TiO2/TBAI ionic liquid polymer electrolyte

Polyvinyl chloride (PVC)/TiO2/x wt % tetrabutylammonium iodide (TBAI) polymers were formed using sol gel and casting methods. Rietveld refinement was used to investigate the structure and microstructure of TiO2. X-ray diffraction, Fourier transform infrared and energy dispersive X-ray analysis techniques were used to explore the present of TiO2 and TBAI over PVC matrix. SEM analysis was carried out to study the impact of loading the TiO2 nanofiller and TBAI on the surface morphology of host polymer. The possibility of using PVC/TiO2/TBAI in UV shielding is explored. The direct and indirect optical bandgap energies for PVC were reduced from (5.49, 5.15) to (5.47, 5) eV, respectively, as it was loaded with nano TiO2. Upon loading the PVC/TiO2 with different amounts of TBAI, the direct and indirect optical band gaps reduced further to (5.33, 4.61) eV and another two bands appeared (3.74–3.8, 2.96–3) eV for direct transition and (2.99–3.19, 2.19–3.36) eV for indirect transition. The values of dielectric constant, optical conductivity and nonlinear optical parameters became highest as the amount of TBAI became 25 wt % while the values of the surface and volume energy loss functions became highest as the content of TBAI became 5 wt %. The fluorescence intensity of the pristine PVC was greatly enhanced when it was loaded with TiO2. Further enhancement in luminescence intensity was obtained upon doping PVC/TiO2 with different weight percents (5, 10, 15, 20, and 25 wt%) from TBAI.

The enhanced polymer-coated graphite anode electrodes for the electrooxidation of glucose

In this study, poly(N-Isopropylacrylamide) (PNIPAM), poly(acrylamide) (PAAM), poly(acrylic acid) (PAAc), and poly(methacrylic acid) (PMAc) polymers are synthesized by radical polymerization method. The chemical composition and surface morphology of the PMAc polymer are examined by micro-Raman spectroscopy and scanning electron microscopy (SEM). The electrochemical measurements are examined by cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) analyses for glucose (Glu) electrooxidation. The characterization analyses reveal that the polymer structure was formed. The electrochemical analysis results indicate that the PMAc/G electrode has higher catalytic activity, stability, and resistance compared to other electrodes with a specific activity of 1.7 mA/cm2.

Microplastic abundance, distribution, and characterization in freshwater sediments in Iran: a case study in Kermanshah city.

This paper focuses on abundance, distribution, and characteristics of microplastics (MPs) in freshwater sediments of Sarab Niloofar Lake, Kermanshah, Iran. After selecting an appropriate method for extraction of MPs, the characterization such as polymer types, surface morphology, and trace elements has been determined using Fourier transform infrared spectroscopy, scanning electron microscopic, and energy-dispersive X-ray spectroscopic analysis, respectively. The results highlighted that all sampling locations were contaminated by MP abundance ranged from 1733.33 to 4400 items kg-1d.w with an average of 2483.59 ± 805.30 items kg-1d.w. MPs with a size range of 0.025 to 1mm (25-1000μm) were the most frequently detected MPs in size (62%). Furthermore, the MPs found in this area mainly contain fiber (61%), fragment (19%), film (9%), foam (6%), and pallet (5%). The main color for detected MPs in sampling stations was black (51%) and followed by white/transparent (27%), red (11%), blue (7%), and yellow (4%). The results of polymer identification revealed that the polyethylene, polystyrene, polyurethane, and polypropylene were the principal polymers. This research work emphasized that various types of MPs have been distributed in freshwater sediments of Sarab Niloofar Lake, which is a first useful data for MPs in one the most important Kermanshah's tourist area.

Enhanced Electrochemical Performance of PEO-Based Composite Polymer Electrolyte with Single-Ion Conducting Polymer Grafted SiO2 Nanoparticles.

In order to enhance the electrochemical performance and mechanical properties of poly(ethylene oxide) (PEO)-based solid polymer electrolytes, composite solid electrolytes (CSE) composed of single-ion conducting polymer-modified SiO2, PEO and lithium salt were prepared and used in lithium-ion batteries in this work. The pyridyl disulfide terminated polymer (py-ss-PLiSSPSI) is synthesized through RAFT polymerization, then grafted onto SiO2 via thiol-disulfide exchange reaction between SiO2-SH and py-ss-PLiSSPSI. The chemical structure, surface morphology and elemental distribution of the as-prepared polymer and the PLiSSPSI-g-SiO2 nanoparticles have been investigated. Moreover, CSEs containing 2, 6, and 10 wt% PLiSSPSI-g-SiO2 nanoparticles (PLi-g-SiCSEs) are fabricated and characterized. The compatibility of the PLiSSPSI-g-SiO2 nanoparticles and the PEO can be effectively improved owing to the excellent dispersibility of the functionalized nanoparticles in the polymer matrix, which promotes the comprehensive performances of PLi-g-SiCSEs. The PLi-g-SiCSE-6 exhibits the highest ionic conductivity (0.22 mS·cm-1) at 60 °C, a large tLi+ of 0.77, a wider electrochemical window of 5.6 V and a rather good lithium plating/stripping performance at 60 °C, as well as superior mechanical properties. Hence, the CSEs containing single-ion conducting polymer modified nanoparticles are promising candidates for all-solid-state lithium-ion batteries.

Study of the morphology of shoe sole composites based on domestic suspension polyvinyl chloride and ethylene-vinyl acetate copolymer

The paper studies the surface morphology of the initial polymers and the mixture using a scanning electron microscope SEM - EVO MA 10 (Zeiss, Germany). The X-ray phase analysis was carried out on a Panalytical Empyrean diffractometer. It has been proven that polymer mixtures based on domestic suspension polyvinyl chloride and ethylene-vinyl acetate copolymer, obtained by the method of "thermomechanical" mixing, are two-phase systems consisting of a phase of polyvinyl chloride and an ethylene- vinyl acetate copolymer. It was concluded that suspension polyvinyl chloride is fundamental in this system, which determines the main deformation-strength properties of the mixture. In the process of mixing a certain ratio of copolymer and thermoplastic, two-phase systems are formed, that is, mechanical mixtures of technologically compatible polymers with very close values of solubility parameters are formed. It has been determined that polymer mixtures based on domestic suspension polyvinyl chloride and an ethylene-vinyl acetate copolymer, obtained by the method of "thermomechanical" mixing, are two-phase systems consisting of a phase of polyvinyl chloride and an ethylene-vinyl acetate copolymer.

Study of the surface properties of polypropylene by enzyme treatment

Surface modification of polypropylene is performed in this work by enzyme-catalyzed post-processing strategy. The polyDOPA was synthesized by in-situ polymerization in the present of laccase and deposited on the polypropylene surface. The effect of various process variables namely processing step, pH, time, and temperature is studied at various levels. The results show that one-bath and one-step method is the optimal mode. Various functional groups incorporated to the polymer surface are confirmed by attenuated total reflectance-Fourier-transform infrared spectroscopy. The effect of process variables on surface morphology of polymers is evaluated by scanning electron microscopy, revealing that the surface of the polypropylene is covered with thin burrs, and these are regarded as polyDOPA adhered after treatment. Furthermore, the electrostatic charge decay time and contact angle as well as capillary wetting measurements of the modified polypropylene are 0.61 s and 75.33°, respectively, indicating its fine anti-static electricity and better wettability. Besides, this material shows dark gray colors and exhibits excellent ultraviolet-resistance performance. Interestingly, the modification process nearly has no influences on the mechanical property.

Structural, morphological, optical, and thermal properties of electrospun PbS/PVP-PEO nanofibers

This study describes the preparation and characterization of PVP-PEO nanofibers filled with PbS nanoparticles. The effect of polymer concentrations, surface morphology, and diameter distribution studies of the nanofibers was evaluated by Scanning Electron Microscopy (SEM). The SEM images revealed that smooth and homogeneous nanofibers could be achieved at 12% PVP-PEO (50:50 wt%) concentration. The XRD and TEM analysis confirmed the formation of PbS nanoparticles in the PVP-PEO blend matrix, which also revealed the high crystalline behaviour of the PbS nanoparticles. The XRD data showed that the intensity and average crystallite size increase with PbS concentration. The FTIR and TGA studies revealed the interaction between PbS nanoparticles and the PVP-PEO blend matrix. UV–Vis diffuse reflectance studies have shown that the reflectance onset shifted toward a blue shift than bulk PbS. The optical bandgap determined using the Kubelka-Munk function lies 1.08–1.56 eV range by varying PbS concentration.

Detection of Carvacrol Content in Oregano Essential Oil by Molecularly Imprinted Polymer Coated Quartz Crystal Microbalance Sensor

The essential oil extracted from the oregano (Origanum vulgare) is rich in phenolic compounds that have strong antioxidant and antibacterial properties. Carvacrol is the major component of oregano essential oil. The current study describes the use of a molecularly imprinted quartz crystal microbalance (QCM) sensor to detect carvacrol in oregano essential oil. For the formation of the sensing film, the surface of a quartz crystal with a silver electrode was modified by simple drop coating with a synthesized polymer solution and thermally polymerized at 95°C in an inert atmosphere. The polymer was synthesized by copolymerization of styrene, methyl methacrylate, acrylonitrile and divinylbenzene in an optimum ratio with template carvacrol. The analytical performance of the sensor has been observed to be reasonably good (sensitivity – 1.24Hz/ppm) and has adequate repeatability and reproducibility. Linear calibration curves were obtained in the concentration range of carvacrol between 5–300 ppm. The molecularly imprinted polymer structure and surface morphology were analyzed by FTIR spectroscopy, SEM and AFM. Validation of the proposed sensor with oregano essential oil samples has been performed by correlating the frequency deviation of the sensor with the estimations of carvacrol obtained from gas chromatography.

Properties of cross-linked copolymers of polypropylene glycol maleate with acrylic acid obtained at various concentrations of the RAFT agent

The initial polypropylene glycol maleate has been obtained by the polycondensation reaction of maleic anhydride and propylene glycol. The molecular weight of the synthesized unsaturated polyester resin has been determined. The copolymers under study have been obtained by radical copolymerization of p-PGM. The possibility of synthesizing new polymers based on p-PGM with acrylic acid in the presence of a RAFT agent has been shown. The effect of RAFT agent concentration on the network density and product yield has been studied. It has been found that the yield of the cross-linked polymer decreases, its swelling capacity increases, and the yield of the linear polymer increases with an increase in the RAFT agent concentration. The effect of organic solvents, pH, and low-molecular-weight salts on the swelling degree of the synthesized copolymers has been investigated. The research results demonstrate that the susceptibility of polymer hydrogels to organic solvents and changes in pH, and low molecular weight salts, is affected by the amount of RAFT agent in the polymer. The synthesized objects have been characterized by infrared spectroscopy. Scanning electron microscopy has estimated the polymer surface morphology and pore sizes

Synthesis of porous polymers by means of Michael addition reaction of multifunctional acetoacetate and poly(ethylene glycol) diacrylate

Michael-addition reaction between multifunctional-acetoacetate, meso-erythritol tetra-acetoacetate (ETAA) or d-sorbitol hexa-acetoacetate (SHAA), and poly(ethylene glycol) diacrylate (PEGDA) has been investigated to obtain the corresponding network polymer. The reactions in mixtures of ethanol (EtOH) and dimethyl sulfoxide (DMSO) using 1,8-diazabicyclo[5.4.0]undecane-7-ene (DBU) as a catalyst successfully yielded porous polymers. Polymerization conditions, such as EtOH/DMSO volume ratio, DBU/PEGDA feed ratio, and monomer concentration, strongly affected the morphology of the network polymer products, i.e., gel, porous polymer, or precipitate. The surface morphology of the porous polymers showed connected spheres with diameters ranged from 2 μm to 50 μm. The monomer concentration and molar mass of PEGDA affected the diameter of the spheres in the porous polymers. All the porous polymers were soft and flexible, and were not breakable by compression. Various solvents were absorbed into the porous polymer due to their high affinity with polyethylene glycol units in the network structure.

Selective Metallization of Polymers: Surface Activation of Polybutylene Terephthalate (PBT) Assisted by Picosecond Laser Pulses

The selective metallization of nonconductive polymer materials has broad applications in the fields of integrated circuit technology and metallized patterns. This work discusses a methodology to pattern metal tracks on polybutylene terephthalate substrates. The process consists of three steps: 1) surface patterning with picosecond laser pulses (1030 nm) in air, 2) Pd seeding via treatment in PdCl2solution, and 3) selective metallization via electroless copper deposition. Picosecond laser irradiation promotes not only surface roughening but also chemical modification to enable Pd seeding as the polymer surface acquires the ability to reduce Pd(II)‐chloride species to metallic Pd. The laser parameters, as well as the PdCl2concentration and seeding temperature, have an influence on the polymer surface morphology, the concentration and distribution of metallic Pd, and the copper layer properties. Homogeneous copper layers with well‐defined geometries, good coating‐substrate adhesion, and high electrical conductivity can be obtained. This is ascribed to the synergistic effect of the chemical surface activation and roughness development (from 0.13 to ≈1.6 μm). As the patterning and surface activation are performed in air, directly on the as‐received polymer substrate, this methodology shows great potential for metallization of electronic devices with 3D complex geometries.

Impact of print bed build location on the dimensional accuracy and surface quality of parts printed by multi jet fusion

Multi Jet Fusion (MJF) is one of the newly developed additive manufacturing techniques, based on the use of powder bed fusion technology. It provides the opportunity to build up 3D, complex polymer geometries, without the need for support structures. This study evaluates the effect of build location across a 380 × 284 mm2 build plate, on both the dimensional accuracy and surface quality of polyamide 12 (PA12) parts printed using the MJF technique. The cube test samples were printed at each of the four corners and the center of the build plate. Dimensional deviations were determined using optical metrology measurements, while surface deviations were measured using 2D tactile and 3D optical profilometers. The density and the degree of crystallinity of the samples were determined using the Archimedes method and Differential Scanning Calorimetry analysis, respectively. Moreover, the morphology of the internal polymer surfaces was evaluated using Scanning Electron Microscopy. It was concluded that while overall printed part dimensions and crystallinity homogeneity were relatively uniform across the build plate, some variations were observed. Parts printed in particular, closer to the front of the build plate exhibited higher porosity, higher surface roughness along with the highest level of geometry deviation, compared with the CAD drawing. This is likely to be associated with some non- uniformities in heating and cooling of the PA12 polymer parts across the build plate.

Effect of nonvertical ion bombardment due to edge effects on polymer surface morphology evolution and etching uniformity

Maintaining uniform sample etching during a plasma process is a critical requirement for applications in large-scale wafer processing. The interface between the plasma and the sample surface is defined by the plasma sheath, which accelerates ions toward the sample surface. In areas where the plasma sheath is not parallel to the sample surface, such as near the sample edges, the incident ions arrive at shallower, off-normal angles that can result in a greater etch yield relative to other areas of the sample. This phenomenon leads to nonuniform etching, along with characteristic surface morphology evolution. In this work, we utilized a combination of spatial ellipsometry for etching behavior, atomic force microscopy (AFM) for surface morphology evolution, and power spectral density (PSD) analysis to quantify the extent and spatial dependence of the nonuniform etching near the sample edges. The spatial ellipsometry indicated that a region extending for about 1000 μm from the sample edge experiences approximately 10%–15% more thickness loss (∼10–15 nm) relative to areas near the center of the sample under the tested processing conditions. Within this area, the greatest rate of change in the sample thickness occurs within 5 Debye lengths or ∼300 μm from the sample edge. Via AFM analysis, we detected the presence of ripple features that are consistent with directional ion impacts caused by deflection of ions from normal incidence on the surface morphology [Merkulov et al., Appl. Phys. Lett. 80, 4816 (2002)] AFM scans performed in two different sample orientations confirmed that the ripple features are oriented perpendicular to the direction of incident ions and propagate along the direction of the incident ions. Correspondingly, the magnitude of surface roughness decreases as the distance from the sample edge increases. The ripple features were quantified via PSD analysis, which found the presence of a greater population of long-wavelength roughness closer to the sample edge. The findings of this study provide insight into the influence of the plasma sheath distortions near sample edges on the extent of nonuniform sample etching and characteristic surface morphology evolution in plasma etching applications.

Морфология поверхности полимеров с молекулярными отпечатками на основе полиимида

В работе получены полимеры с молекулярными отпечатками бензоата натрия на поверхности электродов пьезосенсоров. Широкое использование консервантов в пищевой промышленности спо-собствует развитию экспресс-методов их анализа модифицированными пьезосенсорами. Цель работы: анализ морфологии поверхности полимеров с молекулярными отпечатками, полученных на основе полиимида методом сканирующей силовой микроскопии.Полимеры с молекулярными отпечатками получены на основе сополимера диангидрида 1,2,4,5-бензолтетракарбоновой кислоты с 4,4'-диаминодифенилоксидом, производства ОАО МИПП НПО «Пластик», г. Москва. В качестве темплата использовали бензоат натрия. Предполимеризацион-ную смесь наносили на поверхность электродов пьезосенсоров шпателем или методом штампования. Проводили термоимидизацию в сушильном шкафу в два этапа: первый этап проходил при 80oС, вто-рой – при 120oС. После полимеризации пленки, сенсоры охлаждали до комнатной температуры, затем помещали их в дистиллированную воду на 24 часа для удаления шаблона.Исследование морфологии поверхности полученных полимерных пленок проводили с помо-щью сканирующего силового микроскопа (ССМ) «Solver P47 PRO» производства ЗАО «НТ-МДТ» в полуконтактном режиме зондом NSG03 с жесткостью 1.74 Н/м. Обработку изображений проводили программой ФемтоСкан-001.Анализ морфологии поверхности пленок показал, что нанесение предполимеризационной смеси штампом приводит к формированию более равномерной поверхности с перепадом высот от 1.4 до 2.6 нм. Использование шпателя приводит к формированию более шероховатой поверхности с вы-сотами в диапазоне 0.9-3.4 нм. Таким образом предложенная методика нанесения смеси является пер-спективной поскольку позволяет получать более воспроизводимые по толщине и шероховатости по-верхности, что позволит повысить точность анализа веществ пьезосенсорами модифицированными этими полимерами.При этом следует учесть, что при формировании полимерной пленки молекулы-шаблона ча-стично или полностью заглубляются в матрицу полимера, а также располагаются на ее поверхности, образуя глобулярные структуры. Экстракция шаблона с поверхности полимера приводит к появлению полостей комплементарных молекулам бензоата натрия.

아크릴아마이드와 아크릴산을 이용한 Polypropylene Glycol Maleate Phthalate 기반 공중합체 합성

The possibility of synthesizing new multifunctional terpolymers based on polypropylene glycol maleate phthalate with acrylamide and acrylic acid was shown. The basic laws of the process of radical terpolymerization in a dioxane medium were studied at various molar ratios of the reactants. The block length, transition probabilities, and Harwood block parameter of the terpolymers synthesized, which reflect information on the location of macroradicals in the chain, were calculated. The radical terpolymerization constants, indicating the possibility of copolymers to form structures with a free distribution of units, were calculated with the help of the Mayo-Lewis equation. The method of scanning electron microscopy was used to study the surface morphology of polymers and to evaluate the surface pore sizes. There were carried out investigations on the effect of pH of the medium and organic solvents on the degree of swelling of the samples studied. Using thermogravimetric analysis, the thermal decomposition of the synthesized terpolymer based on polypropylene glycol maleate phthalate with acrylamide and acrylic acid was studied. The features of mass loss and thermal transformations upon heating were revealed. It was found that the process of thermal degradation intensified in the range of 339-428 °С with the maximum weight loss of the sample ~78.64%.

Surface morphology and drug loading characterization of 3D-printed methacrylate-based polymer facilitated by supercritical carbon dioxide

Polymers have been shown to have viable applications in the biomedical field, from controlled drug delivery systems to biological implants. The preparation and processing of polymers into bio-systems have nevertheless encountered some technical challenges in part customization and adverse effects to the human body functions and recovery. This study proposes the utilization of 3D printing technology and supercritical carbon dioxide (scCO2) processing to deliver a drug-impregnated polymeric material system which can be engineered and tuned to suit a particular implantation procedure and dramatically improve patient outcomes. In this work, an acrylate-based polymer is 3D-printed using stereolithography, then impregnated with flurbiprofen drug using scCO2. Drug loading above 24 % by mass is achievable under the tested conditions. The correlation of drug loading and material surface roughness with different process parameters, including 3D printing layer thickness, scCO2 processing temperature, pressure and treatment time, are investigated and empirically modeled using the linear regression methods.

Preparation of molecularly imprinted polymers for recognition and extraction of benzoylureas from apple samples

ABSTRACTIn this work, diflubenzuron (DBZ) molecularly imprinted polymers (MIPs) were synthesized by precipitation polymerization. The polymers were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), dynamic light scattering (DLS). The influences of synthetic conditions including template molecules, functional monomers and crosslinker on the surface morphology, particle size and size distribution of polymers were investigated. Scatchard analysis indicated the presence of specified recognition sites in MIPs. The Sips model was fitted better to the equilibrium data of MIPs over whole concentrations. The pseudo-second-order kinetic model was well fitted to the experimental data of adsorption kinetic experiment, suggesting the chemisorption mechanism between MIPs and DBZ. Four structurally similar compounds were used for the selectivity test of MIPs. It was observed that MIPs can selectively rebind the template molecules (DBZ) under the interference of four other structurally similar compounds. The application of MIPs in solid-phase extraction (SPE) offers a method for extraction and determination of benzoylureas (BUs) pesticides in apple samples prior to high-performance liquid chromatography (HPLC) analysis.

Synthesis of new azo dye polymers based on naphthol by oxidative polycondensation: antimicrobial activity and fastness studies

Azo dye polymers were synthesized by an oxidative polycondensation reaction of naphthol based azo dyes with the oxidants NaOCl in an aqueous alkaline medium. These synthesized azo dye polymers were characterized by UV-Vis, FT-IR, 1H NMR techniques. The surface morphology of the azo dye polymers was understood by Scanning Electronic Microscopic study(SEM). The changes in weight in relation to change in temperature of synthesized compounds the was studied by TGA/DTA analysis. All the novel polymers were characterized to determine molecular weights by gel permeation chromatography(GPC). All of the azo dye monomers and polymers were researched for antibacterial (Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus Enterococcus faecalis, Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica) and antifungal (Kluyveromyces fragilis, Saccharomyces cerevisiae, Candida albicans) activities. When results of antibacterial activity of synthesized compounds was compared with standard Ampicillin, Streptomycin Sulfate, Nystatin. it is seen that the azo dye monomers had good antibacterial activity whereas the azo dye polymers did not have as good activity as the monomers. The dyes were examined in respect of their washing, water, sweat (acid and base) and frictional (dry and wet) fastness. From the results, It was found that The fastness properties of the azo dye monomers are better than the polymers. Because the bonding ability to the fabric in the monomers is better than the long chain polymers having a high molecular weight.

Microplastic pollution in the sediments of Sidi Mansour Harbor in Southeast Tunisia

Despite the increasing interest in microplastic (MP) research, the accurate prevalence, distribution and fate of these materials in the environment is yet poorly known and, consequently, a focus of debate. Hence, to better ascertain the presence of microplastics in specific environments, samples from 35 random sites distributed across a 4200-meter long section from the area of Sidi Mansour, Sfax-Tunisia, were collected and analyzed. MPs were extracted, digested with potassium hydroxide and dyed with Eosin B, for visual microscopy counting and sorting. Polymer composition and surface morphology were identified by FTIR-ATR spectroscopy and SEM microscopy. Total abundances ranged from 252 to-5332 particles per m2 where fragments and granules were the most frequent types of microplastics. These findings highlight the considerable presence of these materials in the studied harbor region and underscore the density dependence on the distribution and occurrence of MPs and how these tend to accumulate in the sandy sediments.