Grafting Process Research Articles

Corneal Endothelium Viability Assay Using Trypan Blue Dye After Preloaded Descemet Membrane Endothelial Keratoplasty Graft Preparation.

The purpose of this study was to establish a validated method, consistent with Eye Bank Association of America medical standards, for evaluating endothelial cell loss (ECL) from an entire Descemet membrane endothelial keratoplasty (DMEK) graft using trypan blue dye as an alternative to specular microscopy. Twenty-nine corneas were prepared for preloaded DMEK by a single technician, and the endothelium was stained with trypan blue dye for 30 seconds. The technician estimated total cell loss as a percentage of the graft and captured an image. Images were evaluated by a blinded technician using ImageJ software to determine ECL and compared with endothelial cell density from specular microscopy. Tissue processing intervals were analyzed for 4 months before and after implementation of this method. For the 29 grafts, there was no statistically significant difference ( t test, P = 0.285) between ECL estimated by a processor (mean = 5.8%) and ECL calculated using an ImageJ software (mean = 5.1%). The processor tended to estimate greater ECL than the actual ECL determined by ImageJ (paired t test, P = 0.022). Comparatively, postprocessing endothelial cell density measured by specular microscopy were higher compared with the preprocessing endothelial cell density (mean = 4.5% P = 0.0006). After implementation of this evaluation method, DMEK graft processing time intervals were reduced by 47.9% compared with specular microscopy evaluation ( P < 0.001). Our results show that visual ECL estimation using trypan blue staining by a DMEK graft processor is a reliable and efficient method for endothelial assessment. Unlike specular microscopy, this method achieves comprehensive visualization of the entire endothelium, reduces total time out of cold storage, and decreases total time required to prepare and evaluate DMEK grafts.

Synergistic chemo-photothermal therapy using gold nanorods supported on thiol-functionalized mesoporous silica for lung cancer treatment

Cancer therapy necessitates the development of novel and effective treatment modalities to combat the complexity of this disease. In this project, we propose a synergistic approach by combining chemo-photothermal treatment using gold nanorods (AuNRs) supported on thiol-functionalized mesoporous silica, offering a promising solution for enhanced lung cancer therapy. To begin, mesoporous MCM-41 was synthesized using a surfactant-templated sol–gel method, chosen for its desirable porous structure, excellent biocompatibility, and non-toxic properties. Further, thiol-functionalized MCM-41 was achieved through a simple grafting process, enabling the subsequent synthesis of AuNRs supported on thiol-functionalized MCM-41 (AuNR@S-MCM-41) via a gold-thiol interaction. The nanocomposite was then loaded with the anticancer drug doxorubicin (DOX), resulting in AuNR@S-MCM-41-DOX. Remarkably, the nanocomposite exhibited pH/NIR dual-responsive drug release behaviors, facilitating targeted drug delivery. In addition, it demonstrated exceptional biocompatibility and efficient internalization into A549 lung cancer cells. Notably, the combined photothermal-chemo therapy by AuNR@S-MCM-41-DOX exhibited superior efficacy in killing cancer cells compared to single chemo- or photothermal therapies. This study showcases the potential of the AuNR@S-MCM-41-DOX nanocomposite as a promising candidate for combined chemo-photothermal therapy in lung cancer treatment. The innovative integration of gold nanorods, thiol-functionalized mesoporous silica, and pH/NIR dual-responsive drug release provides a comprehensive and effective therapeutic approach for improved outcomes in lung cancer therapy. Future advancements based on this strategy hold promise for addressing the challenges posed by cancer and transforming patient care.

A new approach for grafting plasticized cellulose acetate biodegradable plastic with maleic anhydride: Processing and characterization

AbstractGrafting polymers with reactive maleic anhydride is a common approach for the synthesis of new material with the capability of acting as a compatibilizer in polymer blends. Accordingly, this research showed a new approach for grafting maleic anhydride onto renewable cellulose acetate using an initiator. The grafting process through extrusion showed good stability with continuous production of all grafted samples. Moreover, two different grafting processes, namely one‐step and two‐step processes, were shown to produce materials with very similar characteristics. Grafting of maleic anhydride onto cellulose acetate by reacting with its hydroxyl groups was confirmed by both Fourier transform infrared spectroscopy and nuclear magnetic resonance analysis. Rheological studies also demonstrated the enhanced flowability and lower viscosity of the grafted material in comparison to the plasticized cellulose acetate.Highlights Grafting maleic anhydride onto plasticized cellulose acetate by reactive extrusion. Detection of grafted maleic anhydride onto cellulose acetate through NMR analysis. High thermal stability of grafted materials. Significant reduction in viscosity of plasticized cellulose acetate after grafting

A PEGylated PVDF Antifouling Membrane Prepared by Grafting of Methoxypolyethylene Glycol Acrylate in Gama-Irradiated Homogeneous Solution.

In this study, methoxypolyethylene glycol acrylate (mPEGA) served as a PEGylated monomer and was grafted onto polyvinylidene fluoride (PVDF) through homogeneous solution gamma irradiation. The grafting process was confirmed using several techniques, including infrared spectroscopy (FTIR), thermodynamic stability assessments, and rotational viscosity measurements. The degree of grafting (DG) was determined via the gravimetric method. By varying the monomer concentration, a range of DGs was achieved in the PVDF-g-mPEGA copolymers. Investigations into water contact angles and scanning electron microscopy (SEM) images indicated a direct correlation between increased hydrophilicity, membrane porosity, and higher DG levels in the PVDF-g-mPEGA membrane. Filtration tests demonstrated that enhanced DGs resulted in more permeable PVDF-g-mPEGA membranes, eliminating the need for pore-forming agents. Antifouling tests revealed that membranes with a lower DG maintained a high flux recovery rate, indicating that the innate properties of PVDF could be largely preserved.

Mechanical, Rheological, and Heat Seal Properties of 1‐Octene Grafted Low Density Polyethylene Films

AbstractHeat seal and mechanical properties of 1‐octene grafted low density polyethylene films containing various concentrations of Dicumyl peroxide as the initiator and 1‐octene grafting agent is investigated through using experimental measurements. The results of differential scanning calorimeter (DSC) measurements revealed that the melting temperature shifts to higher values and the peak of the DSC curve becomes wider with the increase of 1‐octene concentrations. Thermogravimetric analysis (TGA) revealed a higher thermal stability up to 20 °C for 1‐octene grafted PE compared with neat LDPE alloy. The results of stress–strain measurements revealed that the 1‐octene grafted PE alloys has higher tensile strength in comparison with neat PE alloy and samples containing only DCP initiator. The results of heat seal analysis indicated that both DCP initiator and 1‐octene tended to offer a moderate increase peel strength of PE alloy. DMTA measurements for various grafted PE alloys show a higher damping factor in comparison with neat LDPE alloy. Rheological measurements indicated a higher storage modulus up to 25% and higher complex viscosity for grafted PE samples containing 1‐octene comonomer.

Fabrication of Glycidyl Methacrylate (GMA) Grafted Cellulose from Rice Straw

The purpose of this study was to prepare and characterize cellulose grafted with glycidyl methacrylate (GMA). Cellulose was isolated from rice straw by chemical method. The acid concentration used during the hydrolysis process affects the size of the cellulose produced, therefore in this study different concentrations of sulfuric acid (50%, 60%, and 70%) were used. Particle Size Analyzer (PSA) results showed the best concentration of sulfuric acid was 50%. Glycidyl methacrylate-grafted cellulose (GMA-g-C) was prepared by different concentration of GMA (15%, 20%, and 25%). GMA-g-C particles were characterized by FT-IR and XRD. FT-IR spectra confirmed the formation of GMA-g-C and XRD data showed the decrease in crystallinity of cellulose after grafting process. The optimum grafting conditions were obtained at 20% GMA with a grafting percentage (Pg) of 233.3% and grafting efficiency (GE) of 27.26%.

Systematic enhancement of microbial decontamination efficiency in bone graft processing by means of high hydrostatic pressure using Escherichia coli as a model organism.

To obtain bone allografts that are safe for transplantation, several processing steps for decellularization and decontamination have to be applied. Currently available processing methods, although well-established, may interfere with the biomechanical properties of the bone. High hydrostatic pressure (HHP) is known to devitalize tissues effectively while leaving the extracellular matrix intact. However, little is known about the inactivation of the contaminating microorganisms by HHP. This study aims to investigate the ability of high-pressure decontamination and to establish a treatment protocol that is able to successfully inactivate microorganisms with the final goal to sterilize bone specimens. Using Escherichia coli (E. coli) as a model organism, HHP treatment parameters like temperature and duration, pressurization medium, and the number of treatment cycles were systematically adjusted to maximize the efficiency of inactivating logarithmic and stationary phase bacteria. Towards that we quantified colony-forming units (cfu) after treatment and investigated morphological changes via Field Emission Scanning Electron Microscopy (FESEM). Additionally, we tested the decontamination efficiency of HHP in bovine cancellous bone blocks that were contaminated with bacteria. Finally, two further model organisms were evaluated, namely Pseudomonas fluorescens as a Gram-negative microorganism and Micrococcus luteus as a Gram-positive representative. A HHP protocol, using 350 MPa, was able to sterilize a suspension of stationary phase E. coli, leading to a logarithmic reduction factor (log RF) of at least -7.99 (±0.43). The decontamination of bone blocks was less successful, indicating a protective effect of the surrounding tissue. Sterilization of 100% of the samples was achieved when a protocol optimized in terms of treatment temperature, duration, pressurization medium, and number and/or interval of cycles, respectively, was applied to bone blocks artificially contaminated with a suspension containing 104 cfu/mL. Hence, we here successfully established protocols for inactivating Gram-negative model microorganisms by HHP of up to 350 MPa, while pressure levels of 600 MPa were needed to inactivate the Gram-positive model organism. Thus, this study provides a basis for further investigations on different pathogenic bacteria that could enable the use of HHP in the decontamination of bone grafts intended for transplantation.

Effect of Plasma pretreatment and Graphene oxide ratios on the transport properties of PVA/PVP membranes for fuel cells

In this study, a novel proton-conducting polymer electrolyte membrane based on a mixture of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) (1:1) mixed with different ratios of graphene oxide (GO) and plasma-treated was successfully synthesized. Dielectric barrier dielectric (DBD) plasma was used to treat the prepared samples at various dose rates (2, 4, 6, 7, 8, and 9 min) and at fixed power input (2 kV, 50 kHz). The treated samples (PVA/PVP:GO wt%) were soaked in a solution of styrene and tetrahydrofuran (70:30 wt%) with 5 × 10−3 g of benzoyl peroxide as an initiator in an oven at 60 °C for 12 h and then sulfonated to create protonic membranes (PVA/PVP-g-PSSA:GO). The impacts of graphene oxide (GO) on the physical, chemical, and electrochemical properties of plasma-treated PVA/PVP-g-PSSA:x wt% GO membranes (x = 0, 0.1, 0.2, and 0.3) were investigated using different techniques. SEM results showed a better dispersion of nanocomposite-prepared membranes; whereas the AFM results showed an increase in total roughness with increasing the content of GO. FTIR spectra provide more information about the structural variation arising from the grafting and sulfonation processes to confirm their occurrence. The X-ray diffraction pattern showed that the PVA/PVP-g-PSSA:x wt% GO composite is semi-crystalline. As the level of GO mixing rises, the crystallinity of the mixes decreases. According to the TGA curve, the PVA/PVP-g-PSSA:x wt% GO membranes are chemically stable up to 180 °C which is suitable for proton exchange membrane fuel cells. Water uptake (WU) was also measured and found to decrease from 87.6 to 63.3% at equilibrium with increasing GO content. Ion exchange capacity (IEC) was calculated, and the maximum IEC value was 1.91 meq/g for the PVA/PVP-g-PSSA: 0.3 wt% GO composite membrane. At room temperature, the maximum proton conductivity was 98.9 mS/cm for PVA/PVP-g-PSSA: 0.3 wt% GO membrane. In addition, the same sample recorded a methanol permeability of 1.03 × 10−7 cm2/s, which is much less than that of Nafion NR-212 (1.63 × 10−6 cm2/s). These results imply potential applications for modified polyelectrolytic membranes in fuel cell technology.

Nanometrology based control: taming radical grafting reactions with attoliter precision.

Precisely controlled micropatterning with organic moieties is a promising route for designing smart surfaces, enabling the development of microsensors and actuators with optimal usage of reactants. Such applications require fine control over the surface modification process, which in turn demands detailed knowledge about the surface modification process. As complex surface kinetics often emerge as a result of even slight modifications of the grafting entity, non-invasive, sensitive and precise closed loop control strategies are highly desirable. In this paper we demonstrate that a nanometrology approach based on quantitative phase imaging (QPI) fulfill all these requirements. We first use the technique to monitor surface photografting kinetics of aryl radicals, comprehensively analyzing the effect of substituents on surface addition reactions. We demonstrate that several aspects of the grafting process are affected in complex ways, rendering open-loop strategies impossible to implement precisely. Then, we show that the operando optical phase signal can be used as a direct feedback, guiding the grafting reaction process. Using relatively simple instrumentation, we demonstrate that general and precise control strategies can be designed and used to control the volume of the grafting material with attoliter precision, in spite of radically different surface modification kinetics spanning several orders of magnitude.

Deciphering metabolite profiling in grafted Solanum nigrum: A comprehensive GC-MS and FTIR analysis

Vegetable grafting plays a significant role in modern agricultural practices, effectively managing abiotic and biotic stresses. Additionally, it offers the advantage of enhancing the phenotypic traits of the scion. This technique has gained widespread acceptance in commercial cultivation, particularly in crops like tomato, watermelon, melon, eggplant, etc., but has not been reported in Solanum nigrum. The appeal lies in its swiftness compared to the traditional method of breeding vegetables with improved environmental stress tolerance. This study focused on identifying and studying the components present in the leaves and fruits of both grafted and ungrafted Solanum nigrum. The GC-MS analysis unveiled a multitude of bioactive compounds, some of which are well-known antioxidants and possess anti-inflammatory properties. These beneficial attributes make them potentially valuable for promoting health and well-being. In addition, Fourier-Transform Infrared Spectroscopy (FTIR) was employed to identify functional groups in the methanolic extracts. The FTIR findings confirmed the existence of diverse functional groups, such as alkanes, alkynes, carboxylic acids, aldehydes, and nitriles, within the selected grafted Solanum nigrum samples. The research outcomes suggest that the extracts could be valuable in managing fungal infections in crops, which may contribute to the successful grafting of Solanum nigrum onto wild rootstocks. The presence of bioactive compounds with antifungal properties in the extracts might enhance disease resistance, making a successful grafting process a viable solution for improved and extended production. This underscores the critical necessity for continued research, highlighting its potential benefits to various domains, including medicine and nutrition.

Adhesion of methylene blue and malachite green to the surface of copolymer synthesized by grafting itaconic acid onto cellulose backbone – experimental and computational studies

This report describes the graft copolymerization of itaconic acid onto cellulose isolated from plantain trunk, using ammonium persulfate as initiator. Optimum grafting condition was established at 0.025 mol/L initiator concentration, 60 °C, 60 min grafting time and 3 g monomer mass. Characterization of the bio-materials indicated the success of the cellulose isolation and the grafting processes. At optimum grafting condition, about 34.0% grafting yield was obtained. With 25 mg of the co-polymer (PTC-g-IA), MB and MG uptake were 72.5 and 56.9 mg/g, respectively. These values represent about 2-fold sorption enhancement when compared with ungranted cellulose (PTC). The sorption process was influenced by solution pH, contact time, dye concentration and temperature. Modeling of the adsorption process indicated that the Pseudo-second-order kinetic model with R2 of unity and the Langmuir isothermal model (R2: 0.9622 (MB) and 0.9880 (MG)) best described the sorption process. Thermodynamic study described a feasible, spontaneous and exothermic process. Free energy value of 7.07 kJ/mol, and ΔH° values of < 20 kJ / mol , suggested a physisorption process. This was corroborated by the computational study which indicated non-covalent interactions between atoms in the dyes and the adsorbents. These interactions were stronger with the co-polymer. The interaction energies calculated for the dye-adsorbent interaction (-38.215, −52.868, −47.299 and −57.848 kJ/mol for PTC-MB, PTC-MG, PTC-g-IA-MB and PTC-g-IA-MG, respectively) show stronger interactions between PTC-g-IA and the dye molecules compared to pure cellulose in line with experimental observations. In overall, this study portrays the cellulose-based co-polymer as having the potential of easily removing MB and MG from wastewater.

Synthesis of Sulfonated Carbon Aerogel from Coir Fiber as Solid Acid Catalyst for Esterification

The increasing human population drives up energy consumption, particularly in the transportation and industrial sectors. Due to the limited and non-renewable availability of fossil fuels encourages various technological developments in the field of renewable energy, including biodiesel. Biodiesel is a biodegradable, non-toxic, and environmentally favorable renewable fuel. One of typical technique of biodiesel production is involving esterification reaction between fatty acids and alcohols by addition acid catalyst to enhance reaction rate. Solid acid catalysts are widely utilized for esterification reaction due to their ability to overcome the drawback of homogeneous catalysts that are difficult to separate. Solid acid catalysts can be produced from cellulose aerogel derived from coir fiber, which is then pyrolyzed into carbon aerogel and sulfonated through grafting process. Although sulfuric acid is a common sulfonic agent used in the catalyst sulfonation process, it has a lengthy grafting time. The addition of 4-aminobenzenesulfonic acid (sulfanilic acid) as a sulfonic agent alternative for sulfuric acid was investigated in this work. This paper reports the methods for preparing cellulose aerogel derived from coir fiber, pyrolysis of cellulose aerogel into carbon aerogel, sulfonation of carbon aerogel into solid acid catalyst, and application of solid acid catalyst for ethyl acetate production. The solid acid catalyst characterization tests include acid density, adsorption-desorption nitrogen analysis, SEM, and FTIR analysis. According to the adsorption-desorption nitrogen analysis results, the sulfonated carbon aerogel catalyst has a specific surface area of 220.29 g/m2. Sulfonated carbon aerogel catalyst with acid density value of 2.81 mmol/g can be obtained at the mass ratio of sulfanilic acid to carbon substrates of 1:1 and pyrolysis temperature of 700°C. The esterification reaction was carried out at 80°C and reached a conversion of 31.37% after 4 h.

UNEXPLAINED UNILATERAL LOWER LIMB NEUROLOGICAL DEFICITS AFTER POSTERIOR SPINAL DECOMPRESSION AND FUSION FOR DEGENERATIVE LUMBAR SPONDYLOLISTHESIS

The observational data from the Spine Patient Outcomes Research Trial (SPORT) confirm the superiority of surgical over conservative management of symptomatic degenerative spondylolisthesis. The most common reported neurologic complications after lumbar posterior decompression and fusion are implant malposition, contralateral foraminal stenosis, hematoma/seroma, arachnoiditis, and nerve root oedema or vascular underlying causes. The current study reported that the patient developed unexpected left side neurological deficit after conventional lumbar posterior spinal decompression surgery for degenerative spondylolisthesis. No intraoperative dural insult. The computer topography (CT) scan and magnetic resonance imaging (MRI) of the spine after index surgery show adequate canal and foraminal decompression. No hardware-related complications or compressive hematoma could explain the patient’s symptoms. The patient recovered completely after removing the redundant posterolateral bone graft. The theory behind that is aggressive posterolateral dissection over the transverse process and abundant application of the bone graft might compress or injure the lumbar plexus. So, we suggested a delicate dissection posterolaterally and only a reasonable amount of bone graft could be applied to prevent such a devastating neurological complication.

Preparation of CNTs/SCF reinforcement using multiple continuous surface treatments to achieve synergistic improvement of epoxy resin-based composites interfacial properties: Towards industrial production of carbon fiber surface treatment

The silane/maleimide co-modified waterborne polyurethane (WPU-M-S) sizing agent and furan-functionalized carbon nanotubes (CNTs-FA) were prepared through chemical modification method. The continuous grafting of carbon nanotubes (CNTs) was realized on the carbon fiber surface by multiple continuous surface treatments, including electrochemical anodizing (EAO), sizing, and chemical grafting of CNTs. The stable physical and chemical connection between carbon fiber, sizing agent, and resin was constructed through the preparation of CNTs/SCF reinforcement. The results of different surface treatment processes such as ultrasound and CNTs grafting process were contrastively studied in terms of surface morphology, microstructure, and mechanical properties. It is reflected that carbon fiber grafted with CNTs-FA (CNTs/SCF) that were prepared by ultrasound assisted chemical grafting provide optimal wettability and interfacial performance. The interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of CNTs/SCF reinforced epoxy resin composites are 115.37 % and 93.91 % higher than those of the untreated carbon fiber (UCF), respectively. The synergistic improvement mechanism of reinforcement on carbon fiber reinforced epoxy resin composites interfacial properties was proposed. This research provides a multiple continuous surface treatment technology that matches the industrial production of carbon fiber to prepare CNTs/SCF reinforcement.

Chemical surface modification for RO membranes based on GO‐mixed polymers for water desalination and biofouling study

AbstractThe modification of conventional polyamide reverse osmosis (RO) membranes with grafted methacrylic acid in the presence of nanomaterial is disclosed. To decrease fouling, this study shows the effectiveness of grafting a hydrophilic methacrylic acid (PMAA) and graphene oxide (GO) nanosheet. The change in membrane surface after coating method with different layers was obvious. The results of the ATR‐FTIR, SEM, AFM, contact angle investigations from side and enhanced rejection and permeability from other side proved that the grafting and modification processes had been successful. In comparison between different modifications based on grafting for thin film and blend RO membranes (RO T, RO P, and RO PG), it was found that the modified membrane nominated RO TG membranes showed less biofouling. The modified membrane with 1.25 weight percent PMAA concentration and 0.4 weight percent distributed GO had the lowest contact angle, the least fouling, the highest chlorine resistance, and improved desalination performance.Highlights Biofouling study for modified RO membranes Chlorine resistance membranes for water desalination Enhanced surface hydrophilicity through grafting of polyamide membranes

Palladium covalently anchored imidazolium functionalized SBA-15: An efficient recoverable heterogeneous catalyst for the hydrocarboxylation of styrene

An efficient Pd/Imi-SBA-15 heterogeneous catalyst was synthesized by a covalent anchoring strategy for the hydrocarboxylation of styrene. Various characterization methods (e.g. FT-IR, XRD, 29Si MAS NMR, BET and ICP) demonstrated that PdCl2 was successfully anchored in the channels of SBA-15, and the mesoporous structure of the SBA-15 substrate was maintained throughout the grafting process. The Pd/Imi-SBA-15 catalyst was proven to be highly efficacious, persistent and reusable in the catalytic system for the hydrocarboxylation of styrene due to an outstanding synergistic effect between H+/Cl−-Pd. The presence of H+/Cl− could promote the formation of the H–Pd complex, and accelerate the reaction process. The DFT calculations indicated that a higher orbital energy level of the adsorbed styrene in the [HPdLCl] complex (L = PPh3) existed than that of free styrene, realizing that the [HPdLCl] complex promoted the electron activity of styrene and thus facilitated the styrene carbonylation process. Furthermore, PPh3 was more likely to induce the transformation of styrene into branched products. In the end, a practicable catalytic mechanism of Pd/Imi-SBA-15 for hydrocarboxylation was proposed.

Suspension Photopolymerization of Methyl Methacrylate and ATRP Grafting of Thermo‐Responsive Polymers Using a Perylediimide Derivative Photoinitiator

AbstractThe first aim of this study is to develop a photo‐ATRP process using methyl methacrylate (MMA) by employing a novel perylenediimide derivative (PDI) as photoinitiator. The analysis of the MMA photopolymerization process kinetics is performed in solution and in bulk, demonstrating control over the reaction progress even if the polymerizations display a slow initiation step. The photo‐ATRP process for MMA in suspension is also developed and the obtained PMMA particles are further used to reinitiate the ATRP polymerization of thermoresponsive polymers (different molecular weights poly(ethylene glycol) methyl ether methacrylate and poly(N‐isopropylacrylamide)) (PNIPAM) in solution and surface‐initiated processes. The synthesized polymers by surface‐initiated process display a bimodal molecular weight distribution with a clear modification of the signal areas ratio depending on the grafted monomer and on the reaction conditions. The grafting process can take place on the surface of the polymer particles (Mn2), or it can also involve polymer chains located further at the interior of the polymer particles (Mn1). The lower critical solution temperature (LCST) transition is demonstrated for the PNIPAM functionalized polymer particles.

Asphalt Modification with LDPE Plastic Waste Treated with Glacidyl Methacrylate and Benzoyl Peroxide Initiator

The aim of this research is to determine the quality of the softening point test, penetration test and deactivation of modified asphalt from garfted LDPE plasticization waste. And for grafting treatment, use the internal mixer method where GMA and BPO are added to the grafting mixture. From the grafting results obtained, we carried out an FTIR test and identified a wave number of 1728/cm indicating the presence of the C-H or benzene functional group. This can be interpreted as a grafting process which can also be seen at the wave number 1730/cm. This can be interpreted as a grafting process from GMA to LDPE. And for the wave number at 2723/cm, there is a CH3 stetching from the LDPE chain backbone so that what is obtained is the LDPE-g-GMA spectrum. As for the TGA and DSC test results obtained, namely that in DSC the peak value of the number is at a temperature of 160.60 C and the value obtained from TGA is 373.13 C. And to find out the standard of modified asphalt from mixing asphalt with waste The value of the grafted plastic that we carried out was 65.23, for the penetration test it was 53.7 and for the deactivation test it was 55.46. This can be interpreted that all three are in accordance with the 2018 Bina Marga asphalt standards

Melon Robotic Grafting: A Study on the Precision Cutting Mechanism and Experimental Validation

The grafting machine cutting step is the core step of the grafting process. The existing grafting machine cutting mechanism adopts fixed angle cutting and manually adjusts the cutting angle based on experience, and the cutting angle is not definite for rootstock cutting in different growth periods. In this paper, we proposed a method to guide the precise cutting mechanism according to internal and external parameters of melon rootstock at a specific period. First, we constructed a cutting model based on internal and external characteristics of rootstock cutting in the growth period of “two leaves and one core” and clarified the safe cutting area. Second, we designed a rotary precision cutting mechanism for rootstock cutting with automatic angle adjustment and constructed the displacement equation of the cutting trajectory of the cutter according to the cutting model. Last, we examined the cutting effect of the precision cutting mechanism and determined the precise cutting angle of the rootstock cutting mechanism in the growth period. Finally, the cutting effect of the precision cutting mechanism was examined, and the precision cutting angle of the rootstock during the growth period was determined. A comparison test between the precision cutting mechanism and the traditional cutting mechanism was carried out, and visual images of the incision were captured and analyzed. The results show that under the five horizontal cutting angles in the safe cutting area of rootstock, the length of the cut surface is inversely proportional to the cutting angle, and the flatness of the cut surface is directly proportional to the cutting angle. Comprehensive evaluation of the length of the cut surface, the cutting success rate, and the quality of cutting revealed that the average cutting angle of the precision cutting mechanism in the safe cutting area (26°) is better than that of the traditional cutting mechanism. It meets the technical requirements of the cutting technology for mechanically grafted rootstocks. The results provide a reference for studying new rootstock precision cutting mechanisms and cutting angle adaptive control models.

Enhancing the Wettability of Fibre Surface: A Comparative Experimental Study of Different Surface Activation Principles on Single Polyamide Fibre

In this study, we have compared three different principles of surface activation with regard to their effects on the properties of single polyamide fibres. The techniques used include the complexation-mediated surface treatment using CaCl2/EtOH/H2O solution (CEW), the atmospheric pressure plasma treatment with air (APPA) and grafting polymerisation process with 2- hydroxyethyl methacrylate (HEMA). The CEW modification, the plasma treatment and the grafting process induced a decrease in advancing contact angle and thus led to an improved wettability of the polyamide fibre. While for the CEW treatment, the decrease was solely due to a change in topography such as increased surface roughness leading to increased capillary effect, for the APPA and grafting technique the decrease was attributed to a combination of increased surface roughness and increased amount of oxygen or nitrogen-containing groups as detected by XPS. In addition, the fibre fineness decreased in the case of CEW treatment due to a dissolution of polyamide segments during the modification, while it increased in the grafting process due to an additional grafted layer. However, an increase in wetted length was observed for most samples, which was attributed to the increased waviness of the fibres. All treatments induced a decrease in fibre tensile strength that decreased with increasing treatment intensity.