Surface Modification and Dyeing of Ultra-High Molecular Weight Polyethylene Fibers by Plasma Discharge Mode

       In this study Ultra-high molecular weight polyethylene (UHMWPE) fibers were subjected to oxygen/argon plasma treatment in order to improve the wettability without changing bulk properties. The results showed that surface roughnesshave been modified by plasma treatment, indicating that the plasma treatment favored the interaction with dyeing UHMWPE fibers. After the treatment the treated fibers were characterized by using scanning electron microscopy (SEM),Fourier transforms infrared spectroscopy analysis (FT-IR), X-ray Diffraction (XRD), atomic force microscopy (AFM). Dyeability of the modified fibers were investigated by dyeing using disperse blue dye and also fibers were printed with pigment red colour.The obtained results were compared with the dyeability of the untreated fiber. The result showed that a significant increase of K/S value after dyeingandafter printing at dyeing temperature of 100 ° C. Thus, the oxygen/argon plasma treatment of UHMWPE fiber can obtain good dyeing properties overall, plasma treatment has a great improvementof theroughnesssurface and dyeing property of UHMWPE fiber.        تعرضت ألياف البولي إيثيلين عالية الوزن الجزيئي  للعلاج بتحفيز البلازما باستخدام خليط من الارجون والاكسجين من أجل تحسين قابلية الامتصاص دون تغيير خصائص الالياف. أظهرت النتائج أن خشونة السطح قد تم تحسينها عن طريق معالجة البلازما، مما يشير إلى أن معالجة البلازما تحسن التفاعل مع صباغة ألياف البولي إيثيلين عالية الوزن الجزيئي. اختبرت الألياف المعالجة عن طريق جهاز مجهر المسح الإلكتروني (SEM)، حيث يقوم فوراً بالتحليل الطيفي بالأشعة تحت الحمراء (FTIR)، انحراف الأشعة السينية (XRD)، الفحص بمجهر القوى الذرى (AFM). تم فحص صباغة الألياف المعدلة عن طريق الصباغة باستخدام الصبغة الناشرة الزرقاء وطباعة الياف أخرى بالوان البجمنت الحمراء. تمت مقارنة النتائج التي تم الحصول عليها بعد الصباغة مع الألياف غير المعالجة. أظهرت النتيجة ان هنالك زيادة كبيرة في قيمة K / S بعد الصباغة والطباعة عند الصباغة في درجة حرارة 100 درجة مئوية. وبالتالي، فإن معالجة ألياف البولي إيثيلين عالية الوزن الجزيئي  بتحفيز البلازما باستخدام خليط من الارجون والاكسجين يمكن أن تحصل على خصائص صباغة جيدة بشكل عام، والمعالجة بتحفيز البلازما يعمل على تحسن كبير في خشونة السطح وخاصية الصباغة لالياف البولي إيثيلين عالية الوزن الجزيئي. &nbsp

Physicochemical characteristics of Bt (Seeni-1) Vs. local hamid cultivar cotton seed oils

n investigation on physicochemical characteristics of Bt (Seeni-1) vs local Hamid cultivar (cv) cottonseed oils (CSO) was conducted. Protein in Seeni-1 seed was relatively higher than Hamid cv seed. Oil content, ash and fibre of Hamid cv were relatively higher. Ash and oil content in black (chemical delinting) and white (mechanical delinting) seed were relatively higher in Hamid cv. There were no differences between the specific gravity (sp.gr.), refractive index (R.I.) and moisture content of both oils. Free fatty acids (FFA) and iodine value (IV) in Seeni-1 were relatively higher. Saturated fatty acids (SFAs) in Hamid cv oil proved to be more than Seeni-1 oil [automatically the USFA should be higher in Seeni-1]. Phosphorus content in Seeni-1 oil was lower than that of Hamid cv, whereas there was no significant difference in the peroxide value (PV)

The performance of heteroatom-doped carbon nanotubes synthesized via a hydrothermal method on the oxygen reduction reaction and specific capacitance

Due to the increasing demand for electrochemical energy storage, various novel electrode and catalysis materials for supercapacitors and rechargeable batteries have developed over the last decade. The structure and characteristics of these catalyst materials have a major effect on the device's performance. In order to lower the costs associated with electrochemical systems, electrochemical systems, metal-free catalysis materials can be employed. In this study, metal-free catalysts composed of nitrogen (N) and sulfur (S) dual-doped multi-walled carbon nanotubes  were synthesized using a straightforward and cost-effective single-step hydrothermal method. Carbon nanotubes served as the carbon source, while l-cysteine amino acid and thiourea acted as doping elements. As a result of the physicochemical characterization, many defects and a porous structure were noted, along with the successful insertion of nitrogen and sulfur into the carbon nanotube was confirmed. According to the cyclic voltammetry tests for the dual-doped samples in alkaline conditions, the D-CNT2 catalyst exhibited onset potentials of -0.30 V higher than the -0.37 V observed for the D-CNT3 catalyst. This indicates enhanced oxygen–reduction reaction due to the synergistic effects of the heteroatoms in the structure and the presence of chemically active sites. Moreover, the outstanding specific capacitance of the D-CNT2 catalyst (214.12 F g-1 at scanning rates of 1 mV s-1) reflects the effective porosity of the proposed catalyst. These findings highlight the potential of N/S dual–doped carbon nanotubes for electrocatalytic applications, contributing to efficient energy conversion

Surface Modification of Carbon Fibers by Grafting PEEK-NH2 for Improving Interfacial Adhesion with Polyetheretherketone

Due to the non-polar nature and low wettability of carbon fibers (CFs), the interfacial adhesion between CFs and the polyetheretherketone (PEEK) matrix is poor, and this has negative effects on the mechanical properties of CF/PEEK composites. In this work, we established a modification method to improve the interface between CFs and PEEK based chemical grafting of aminated polyetheretherketone (PEEK-NH2) on CFs to create an interfacial layer which has competency with the PEEK matrix. The changed chemical composition, surface morphology, surface energy, and interlaminar shear strength were investigated. After grafting, the interlaminar shear strength (ILSS) was improved by 33.4% due to the covalent bonds in the interface region, as well as having good compatibility between the interface modifier and PEEK. Finally, Dynamic Mechanical Analysis (DMA) and Scanning Electron Microscopy (SEM) observation also confirmed that the properties of the modified CF/PEEK composites interface were enhanced. This work is, therefore, a beneficial approach towards enhancing the mechanical properties of thermoplastic composites by controlling the interface between CFs and the PEEK matrix

Effect of Jute Fiber Modification on Mechanical Properties of Jute Fiber Composite

Recently, the demand for reinforced plastics from natural, sustainable, biodegradable, and environmentally friendly fibers has been rising worldwide. However, the main shortcoming of natural fibers reinforced plastics is the poor compatibility between reinforcing fibers and the matrix. Hence, it is necessary to form a strong attachment of the fibers to the matrix to obtain the optimum performance. In this work, chemical treatments (acid pretreatment, alkali pretreatment, and scouring) were employed on jute fibers to modify them. The mechanical properties, surface morphology, and Fourier transform infrared spectra of treated and untreated jute fibers were analyzed to understand the influence of chemical modifications on the fiber. Then, jute fiber/epoxy composites with a unidirectional jute fiber organization were prepared. Basic properties of the composites such as the void fraction, tensile strength, initial modulus, and elongation at break were studied. The better interfacial adhesion of treated fibers was shown by scanning electron microscope (SEM) images of fractured coupons. Hence, the chemical treatment of jute fiber has a significant impact on the formation of voids in the composites as well as the mechanical properties of jute fiber composites

Non-isothermal crystallization kinetics and its effect on the mechanical properties of carbon fiber/polyphenylene sulfide composites

The degree of crystallization of semi-crystalline thermoplastics is an important factor in determining the final properties of the structure of composite materials. This article studied the non-isothermal crystallization kinetics of carbon fiber (CF) reinforced polyphenylene sulfide (PPS) composites by differential scanning calorimetry (DSC) with various cooling rates from 10 k/min to 70 k/min. The MoZhiShen method was applied to the analysis of the nonisothermal crystallization of the composites. Moreover, the effects of the crystallization behavior of CF/PPS composites on their mechanical properties were also investigated. It was found that the MoZhiShen method can effectively be applied to study the nonisothermal crystallization kinetics of CF/PPS composites. The result indicated that the crystallization peak gradually became strengthened in intensity, and crystallization decreased with increasing the cooling rate. Moreover, the increase in the cooling rate during composite fabrication was found to decrease the flexural properties of the composite, but the energy absorption and the impact strength were significantly increased by 15.1%

Effect of plant ontogeny on yield and chemical constituents of essential oil in Sweet basil (Ocimum basilicum L.) grown in Sudan

Sweet basil (Ocimum basilicum L.), belonging to family Lamiaceae, is very important for its therapeutic and cosmetic potential. The yield and constituents of essential oils in plants are highly dependent on the harvesting time. This study was carried out to assess the effect of plant ontogeny on essential oil yield and chemical constituents for four sweet basil accessions cultivated under irrigation conditions. The essential oils were hydro-distilled from the leaves harvested during the stages of pre-flowering, at flowering and post-flowering. The chemical constituents were determined by GC-MS. The results reveal that the essential oil content ranged from 0.1% to 0.2% at the pre-flowering stage, whereas the oil content obtained at the post-flowering stage was 0.1% for all investigated accessions. The highest essential oil content was recorded at flowering stage (0.2-0.5%). The two wild Sudanese accessions had the maximum content (0.5%). The major chemical constituents, linalool, citral, methyl eugenol, and eucalyptol reported at different developmental stages, varied between 5.73% and 32.93%