Coconut Coir Fiber Research Articles

Silica surface modification using cellulose as a renewable organosilane derived from coconut coir fiber for carbon capture

The properties of silica surface modification for carbon capture were studied, utilizing cellulose-amine as a modification agent derived from dissolved coconut coir fiber. To form bonds with NH2 functional groups through amination processes, cellulosic biomass waste is utilized, which is analogous to replacing alkoxy ligands. The dual-function mixture reagents dimethyl sulfoxide (DMSO) and ammonium hydroxide (NH4OH) were employed in the same system as the amine sources and solvents. Waterglass is used as a source of silica, and the modified particles are formed using a one-step consecutive sol-gel spray drying process used in a direct condensation route. Changes in the concentration of sodium lauryl sulfate (SLS) were examined to determine how they affected the essential parameters of the particles. The template is removed during particle formation without further physical or chemical processing. The particle morphology changed from donut-shaped to spherical after SLS application, as evidenced by the increase in SLS concentration. This also shows that the increase in the particle surface area is directly influenced by the increase in the formation of new pore structures with increasing SLS concentration. Through this mechanism, it is possible to extend the pore size distribution to the meso-macropore regime and initiate the formation of new mesopores. This has a direct impact on the capacity to absorb CO2 gas by increasing the cellulose-amine mass fraction that can be grafted to as high as 32.35 %wt. At an operating pressure of 6 bar, a maximum CO2 gas adsorption capacity of 5.32 mmol/g silica was attained by adding SLS 3 CMC to the silica particles. This value is 2.3 times higher than that obtained when using an aminosilane-based modification agent.

THE X-BAND MICROWAVE ABSORPTION CHARACTERISTICS OF POROUS ACTIVATED CARBON FROM NATURAL RESOURCES

Porous activated carbon (PAC) from bamboo, sisal, and coconut coir fibres with two carbonization steps were prepared and the microwave absorbing characteristics in the frequency range of 8 GHz to 12 GHz were investigated. The PAC based on bamboo, sisal and coconut coir had BET surface areas of 354.79, 141.91, and 25.70 m2/g, respectively. The return loss of -27.3, -25.6 and -16.4 dB was achieved for PAC from bamboo, sisal, and coconut fiber at 10.46, 11.08 and 11.00 GHz, respectively. The microwave absorption of more than 99% for porous activated carbon of bamboo and sisal, and more than 90% for porous activated carbon of coconut coir fiber, is indicated by these return loss values. It is shown by these results that biomass resources can be considered a promising lightweight, cost-effective, and eco-friendly microwave absorber material.

UCS and microscopic experimental study of coconut coir fiber-waterborne epoxy resin composite modified calcium sand

To address the issues of high porosity and low strength in calcium sand of artificial islands, this study focuses on improving the calcium sand’s mechanical properties. The effects of WER curing methods and coconut fiber modification on the UCS and microscopic mechanisms of calcium sand are investigated. The results indicate that both fiber incorporation and the increase in WER ratio can enhance the unconfined compressive strength of calcareous sand, with the addition of a certain amount of coconut coir fiber showing a more significant strength increase. The optimal recommended dosage of WER is 15%, which results in an UCS of 1218 kPa, an increase of nearly 4.27 times compared to 9% WER dosage. Coconut coir fiber has good tensile strength that can improve the compressive strength of calcareous sand after curing. The UCS of calcareous sand cured with a fiber content of 0.3% to 0.5% is increased by 1247 kPa to 1792 kPa compared to cured soil with no fiber. The strong binding nature of WER addresses the issue of large porosity in calcareous sand. Together with the penetrating coconut coir fibers, it forms a three-dimensional reticular framework structure, thereby enhancing the compressive performance of the calcareous sand-cured soil mass.

Experimental investigation of utilizing coconut shell ash and coconut shell granules as aggregates in coconut coir reinforced concrete

In the agricultural industry, coconut shells are one of the most generated wastes worldwide. In particular, studies in the Philippines show that the maximum capacity of the organic decomposition processes of agricultural products is exceeded due to the increasing agricultural activities. On the other hand, in the construction industry, cement production accounts for billions of tons of carbon dioxide emissions yearly. To address the said biowaste disposal problem, and environmental implications of the growing construction industry, this study evaluated the potential of utilizing coconut shell ash (CSA) and coconut shell granules (CSG) in concrete production as alternatives to cement and sand, being the conventional aggregates, respectively. Additionally, coconut coir (CC) was incorporated as fiber reinforcements in concrete. The experiment consisted of 15 mix designs using different proportions of CSA and CSG, ranging from 0% to 20%, and CC fiber reinforcements, ranging from 0% to 2%. The tests conducted on fresh concrete involved measuring its slump and unit weight, while the 28-day cured samples were tested for compressive and tensile strengths. Results showed that high concentrations of CSA, CSG and CC, when combined in the concrete mix, leads to poor workability; on the other hand, the modified mixes generally had lower unit weights than the conventional concrete. These are associated to the higher absorption rate, but lower density of the said agri-wastes than the conventional aggregates. In terms of the compressive and tensile strengths, all modified mixes produced lower strengths than the conventional concrete. Nonetheless, Response Surface Methodology (RSM) was utilised to model the relationship between the different independent variables considered in the study, namely CSA, CSG and CC contents, and their corresponding response to the compressive and tensile strengths. Based on the generated RSM Model, the optimum combination for obtaining the maximum strength consisted of 2% CC, resulting in a compressive and tensile strength of 23.046 MPa and 3.315 MPa, respectively. Overall, CSG-CSA coconut coir reinforced concrete is found to be a viable sustainable alternative for structures requiring low-strength, non-structural concrete, such as concrete slab patios and pathways.

Effect of rice husk ash and coconut coir fiber on cement mortar: Enhancing sustainability and efficiency in buildings

This research investigated energy efficiency, insulation properties together with strength properties and cost-effectiveness, focusing on developing a sustainable mortar. Cement: sand of 1: 2.25 (by weight) mortar with varying rice husk ash (RHA) and coconut coir (CC) fiber contents were prepared. Physical, microstructure, strength, durability, and thermal performances were experimentally examined. Life cycle assessment and cost analysis were numerically examined. Adding CC fiber reduced the longer final setting time found with the RHA-based mortar. With 20 % RHA and 0.5 % CC fiber, weight was reduced by 9.2 % (compared to the conventional mortar), promising a lightweight mortar. Flexural strength was increased by 8.6 % with 0.5 % CC fiber addition, this was further increased to 13.6 % with 10 % RHA in the mixture. 20 % RHA and 0.5 % CC fiber mortar exhibits a temperature difference of 8.7°C, whereas the conventional mortar exhibits a temperature difference of 2.5°C, indicating a reduced thermal conductivity of the RHA-CC fiber mortar. This mortar reduced the CO2 emission, energy consumption, and manufacturing cost by 17.7 %, 13.6 % and 7.0 %, respectively, indicating the sustainability. A cost-effective and energy-efficient lightweight mortar with enhanced thermal insulation and flexural strength was achieved by reinforcing the conventional mortar with 20 % RHA and 0.5 % CC fiber for the applications of dwellings.

The Effect of Adding Coconut Coir Fiber on Compressive Strength, Tensile Strength, and Concrete Flexural Strength in Eco-Friendly Tetrapod Planning in Coastal Areas of IKN Supporting Cities

Beaches often experience erosion or abrasion problems caused by various factors, such as climate change which triggers rising sea levels, high waves, human activities such as beach reclamation, and infrastructure construction that is not environmentally friendly, triggering erosion on the coast. In the coastal area of the city that supports IKN, which is located in the Balikpapan area, Manggar Beach, also experiences abrasion which causes land to narrow in that area. The abrasion that occurs erodes the coastal area around 7-8 meters every year. To produce environmentally friendly infrastructure, this research carried out the addition of coconut fiber waste components to tetrapod concrete used for breakwater construction. In this research, variations in the addition of coir used were 0%, 1%, 2%, 3%, 4% and 5%. The aim was to find out how much influence the addition of coconut coir waste to the concrete mixture had on the compressive strength, tensile strength and flexural strength of the concrete in tetrapods. and produce concrete that uses coconut fiber waste as an alternative material for tetrapod concrete as breakwater armor. Based on the analysis results, the quality of the concrete was 23 Mpa. This value was determined based on wave generation analysis. In addition, it is known that variations in coconut fiber affect the slump, compressive strength, flexural and split tensile test values of concrete. Based on the slump test results, it was found that the greater the variation of coconut fiber in the concrete, the lower the resulting slump test value. In testing the compressive, flexural and split tensile strength, it was found that the optimal composition for adding coconut fiber was 3%, in this composition the amount of coconut fiber fiber was able to improve the mechanical properties of tetrapod concrete compared to other compositions.

Improvement of mechanical and thermal expansion properties of pectinase treatment plant fiber reinforced starch/PBAT composites

AbstractThis study discussed the impact of pectinase treatment on the properties of starch/PBAT composite, using two types of plant fibers such as coconut coir and bamboo fibers. The fibers underwent pretreatment with pectinase assisted by ultrasonics, and the composite was subsequently produced through hot pressing. The research focused on evaluating the thermal properties, mechanical properties, moisture absorption properties, and microstructure of the resulting composites. The findings revealed that the inclusion of pectinase‐treated plant fibers significantly enhanced the composite's strength. In particular, the bending strength of the composite with 15 wt% bamboo fibers exhibited the highest improvement, registering a 65% increase compared to the composite without added fibers. Additionally, the linear expansion coefficient of the plant fiber composite treated with pectinase was notably lower than that without added fibers. Among these, the linear expansion coefficient of the 15 wt% coir fiber composite decreased by 73.4% in the temperature range of 40–80°C compared to the composite without added fibers. The observed effects were attributed to the pectinase treatment, which proved effective in disrupting the network structure of cell walls, eliminating pectin components from fibers, and facilitating enhanced interaction between the fillers and the polymer matrix.Highlights The inclusion of fibers significantly enhanced the composite's strength. 10 wt% of bamboo fibers had a greater impact on the composite's strength than coir fiber. The linear expansion coefficient of the plant fiber composite decreased. The composite with 5 wt% bamboo fiber demonstrated excellent moisture resistance. The pectinase treatment enhanced interaction between fillers and matrix.

Extraction of Lignin from Agro-Waste Coir Fiber by Mild Alkali Treatment: A Statistical Approach for Process Optimization through Response Surface Methodology

Lignin, a biomass with a wide range of applications, can be produced from agro-industrial waste, which can contributes to a reduction in the costs of production as well as the pollution load from the environment. The lignin content in coconut coir fiber is fairly high (40-45%) compared to other biomass. In current study, lignin is extracted from coconut coir fiber using a mildly alkaline solution and moist heat under pressure in an autoclave. Three factors were taken into consideration while designing the experiments: the variation in NaOH concentration, the variation in time and the variation in temperature. The optimal lignin extraction of 305.9742 mg/100 mL was achieved at 107 ºC and a heating time of 130 min by using a central composite design (CCD) of the response surface methodology (RSM).

Analysis of Coir Fiber/Wood Paint as Composite Anti-Weathering Coatings on Traditional Fishing Boats

The low resistance of wood as a frame material for traditional fishing boats against splashing sea water, humidity, and high-temperature fluctuations was studied in this study by adding coconut coir fiber to wood paint, where this mixture will become an anti-weathering composite material. To make compatibility between the fibers from coir which are water-absorbing (hydrophilic) and alkyd paints which are water-repellent (hydrophobic), the author gives special treatment to the coco fibers through an acetone pre-treatment process and hot alkali (hot alkali treatment) by soaking fiber in 10% high-temperature sodium hydroxide NaOH solution. Soaking in this solution is able to modify fibers that have a rough surface and reduce hydrogen bonding thereby improving the interfacial bond between the fiber and the filler in the composite. The results obtained were that the addition of fiber with a weight fraction of 3.40% to the alkyd paint matrix made the composite the most optimal anti-weathering coating.

Assessment of Hydrothermal Treatment Effects on Coir Fibers for Incorporation into Polyurethane Matrix Biocomposites Derived from Castor Oil.

The incorporation of natural lignocellulosic fibers as reinforcements in polymer composites has witnessed significant growth due to their biodegradability, cost-effectiveness, and mechanical properties. This study aims to evaluate castor-oil-based polyurethane (COPU), incorporating different contents of coconut coir fibers, 5, 10, and 15 wt%. The investigation includes analysis of the physical, mechanical, and microstructural properties of these composites. Additionally, this study evaluates the influence of hydrothermal treatment on the fibers, conducted at 120 °C and 98 kPa for 30 min, on the biocomposites' properties. Both coir fibers (CFs) and hydrothermal-treated coir fibers (HTCFs) were subjected to comprehensive characterization, including lignocellulosic composition analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The biocomposites were subjected to water absorption analysis, bending tests, XRD, SEM, FTIR, and TGA. The results indicate that the 30 min hydrothermal treatment reduces the extractive content, enhancing the interfacial adhesion between the fiber and the matrix, as evidenced by SEM. Notably, the composite containing 5 wt% CF exhibits a reduced water absorption, approaching the level observed in pure COPU. The inclusion of 15 wt% HTCF results in a remarkable improvement in the composite's flexural strength (100%), elastic modulus (98%), and toughness (280%) compared to neat COPU. TGA highlights that incorporating CFs into the COPU matrix enhances the material's thermal stability, allowing it to withstand temperatures of up to 500 °C. These findings underscore the potential of CFs as a ductile, lightweight, and cost-effective reinforcement in COPU matrix biocomposites, particularly for engineering applications.

ANALYSIS OF COMPRESSIVE STRENGTH PAVING BLOCKS WITH THE ADDITION OF COCONUT FIBER AND SUPERPLASTICIZER LIQUID

This research was carried out to determine how strong the compressive strength of the Paving Block is to withstand the load above it, by adding coconut fiber and superplasticizer liquid to reduce the impact of environmental pollution. But for Paving Blocks, the effects of adding coconut fiber and superplasticizer liquid are not yet widely known. Further research needs to be done on adding coconut fiber and superplasticizer liquid in making PavingBlocks. The purpose of this research is as a form of knowledge for developing construction materials technology. This research can be used to utilize the potential of existing waste. This research aims to reduce environmental pollution caused by coconut fiber waste, and to use this waste as additional construction material technology and to find out how much compressive strength the Paving Block has so that it can be used as a construction tool. Theaddition of coconut fiber and superplasticizer liquid can improve the performance of Paving Blocks according to SNI 03-0691-1996 (compressive strength). The results from adding coconut fiber and superplasticizer liquid are higher than Normal Paving (without mixed ingredients). Paving Block 1:5 with the addition of coconut fiber and superplasticizer liquid from 5 samples produces an Average Stress fcr' of 305.42 Kg/cm and Paving Block 1:6 withthe addition of coconut fiber and superplasticizer liquid from 5 samples produces an Average Stress -Average fcr' is 237.45 Kg/cm2. Normal 1:5 Paving Block from 2 samples produces an Average Stress fcr' of 203.47 Kg/cm2and normal 1:6 Paving Block from 2 samples produces an Average Stress fcr' of 184.59 Kg/cm2 Keywords: Compressive Strength; Paving Block; Coconut Coir Fiber; Superplasticizer Liquid.

Electric Field Analysis of HDPE/NR Biocomposite Due to Moisture Content Condition

It is critical to develop new insulating materials that can improve the performance of next-generation high-voltage cables used in the construction of future electrical networks. The high electric field reduces solid insulation resistance and causes partial discharge through imperfections in a dielectric, causing the dielectric to age and eventually fail. Moisture is one of the most serious factors the effect the high voltage insulation status of High-Density Polyethylene (HDPE) composites. The main goal of this project is to investigate the electric field intensity of HDPE due to moisture content condition when mixed with 10g, 20g, and 30g of various bio-fillers such as coconut coir fibre, pineapple leaves fibre, and oil palm empty fruit bunch. This can be accomplished by using the Finite Element Method Magnetics (FEMM) 4.2 software to create a two-dimensional (2D) axisymmetric electrostatic model. When compared to unfilled HDPE, the inclusion of bio-filler in HDPE increased the maximum electric field intensity due to moisture content condition. The intensity of the electric field varied with the different percentages of biocomposite loading and their permittivity due to moisture content condition. The results showed, due to moisture content condition, the maximum electric field intensity was significantly lower when HDPE was added with a 10% loading of the oil palm empty fruit bunch (EFB). As a result, EFB bio-filler was the best composition because it tends to improve dielectric properties by having a lower maximum electric field intensity which is 4.214Mv/m due to moisture content condition at the top sphere electrode when compared to other compositions.

Evaluation of sorbent amendments used with stormwater management practices to remove contaminants: Impacts of rainfall intensity and antecedent dry periods

For a comprehensive evaluation of the suitability and efficiency of soil amendments in bioretention systems, it is crucial to investigate the capability of amendments for simultaneously serving three important functions under intermittent and variable flow conditions: removing a wide range of contaminants, supporting plant health, and maintaining media infiltration rate. However, most studies have not considered these important factors and conditions simultaneously, which may overestimate or underestimate the bioretention performance. In this study, a long-term vegetated column study was conducted to investigate the ability of various sorbent amendments– coconut coir fiber (CCF), blast furnace slag (BFS), and waste tire crumb rubber (WTCR) –for removal of metals, nutrients, and polycyclic aromatic hydrocarbons (PAHs) from stormwater. The experiments were performed under intermittent flow conditions considering different runoff intensities and antecedent dry periods (ADP). The long-term effect of bioretention usage on plant health and media infiltration rate was also investigated.All amended and unamended columns were able to remove >99 % of influent metals, except Cu, over the 7-month experiment period with different rain intensities and dry periods; modest effluent Cu concentrations occurred with higher rainfall. The performance of different media for removing PAHs such as naphthalene and acenaphthylene varied with the rain intensity. The BFS-amended media had high phosphate removal capacity (>90 %) under tested conditions. In all columns, nitrate removal was notably affected by changes in stormwater intensity and ADP, with high nitrate removal during heavy rainfall. Over the entire experiment, all media had good infiltration rate within the locally acceptable range (1–25 cm/h). The high iron and aluminum contents of BFS adversely affected the plant health in BFS-amended media. Overall, this study identifies the opportunities and challenges associated with the usage of bioretention amendments, and improves awareness among bioretention designers to consider seasonal effect on the performance of bioretention systems.

The Effect of Difference In Press Time on Physical Properties and Mechanical Particle Board Without Adhesive From Coconut Fiber and Gambier Processed Pulp

This study aims to determine the effect of differences in the length of time when pressing for the manufacture of particle board without adhesive from a mixture of coconut coir fiber and processed gambir leaf dregs on the physical and mechanical properties of the resulting non-adhesive particle board. The method used in this study was a completely randomized design with 5 treatments and 3 replications. Data were analyzed using variance, followed by Duncan`s New Multiple Range Test (DNMRT) at 5% level. The comparison ratio used in the manufacture of particle board without adhesive from coconut coir fiber and processed gambir waste is 60% : 40%. The treatments in this study were A (8 minutes of pressing time), B (10 minutes of pressing time), C (12 minutes of pressing time), D (14 minutes of pressing time), E (16 minutes of pressing time). carried out is a test of physical properties and mechanical properties. The results showed that the length of time of compression affected the physical and mechanical properties of the non-adhesive particleboard. The best treatment was treatment A (pressing time 8 minutes). Observation of physical properties obtained density 0.68 g/cm3, moisture content 13.42%, water absorption 132.87%, thickness swelling 66.84%, mechanical properties fracture toughness (MOR) 90.40 kg/cm2, toughness compressive parallel to the surface of 50.07 kg/cm2, and internal bond (IB) 1.45 kg/cm2.

The Utilization of Coconut Fiber and Marble Waste with Mechanical Tests

The area of coconut plantations in South Aceh Regency was 6839 Ha, out of the total number of sub-districts in South Aceh. South Kluet District was the area with the largest coconut plantation area compared to other districts, reaching 1433 Ha. Coconut coir fiber was usually used for household equipment, such as floor brooms, doormats and rope. Coconut farmers rarely process coconut husks, and after harvest, they just leave the coconut husks piled up under the coconut trees until they rot. In this research, coconut fiber waste was used as reinforcing fiber for composite materials. The aim of this research was to be determined the mechanical strength of marble waste composites mixed with resin and reinforced with coconut fiber. The composition tests carried out were: 85 : 10 : 5, 80 : 10 : 10, 90 : 7.5 : 2.5, and 80 : 12.5 : 7.5. The test carried out on each test specimen composition was a tensile test. From the results of the tests carried out on the test specimens, the maximum stress was found in the composition: (85: 10: 5) 85% Resin, 10% Marble, 5% Coconut Fiber with an average maximum stress value of 29.44827586 N /m2 and the average modulus of elasticity is 0.2415123283 N/m2.

The Characterization of the Sandwich Composite Consisted of Coconut Fibre-Polyester Resin and its Variations of Wood Core

The traditional fishing vessels in Indonesia are usually made of wood material. The weakness of this vessel material is that it is easily weathered when exposed to seawater. For this reason, it is necessary to have vessel material engineering from composite sandwiches. This study aimed to prepare and investigate the flexural test, impact test, optical microscopy (OM), and scanning electron microscopy (SEM) observations of sandwich composites based on coconut fibre-polyester resin and wood core. The fabrication uses a hand lay-up method with a constant volume fraction (20% coconut coir fibre) and wood core variations type. The primary wood variations used are albizia chinensis, mahogany, shorea, and camphor. The Surface modification of fibre and wood core was conditioned without treatment and with treatment with about 5% NaOH solution for 2 hours. The study showed that the highest bending and impact strength was sandwich composite with camphor wood cores with alkali treatment for 39.75 MPa and 37.22 J/cm2, respectively. The OM observations showed that the core and skin interface area failed to delaminate after flexural and impact tests. SEM observations also showed thatthe bond alkalization treatment between the matrix and the fibres was quite good. In the composite skin fracture area, there is a lot of fibre brake, and a little thread pulls out. The skin matrix also shows the presence of voids. Generally, this sandwich composite is feasible for application as a material for traditional fishing vessels.

Pengaruh Variasi Fraksi Volume Komposit Serat Sabut Kelapa Matrik Polyester Terhadap Kekuatan Tarik

In the era of the use of technology that is currently developing. Has a major impact on the use of fiber as a composite material. One of the widely used fibers is coconut coir. Coconut coir is a natural fiber material that can be an alternative choice in the manufacture of composites. The purpose of this study was to obtain optimal tensile test values of coco fiber composite materials with variations in volume fraction of 3%, 5% and 7% and fiber lengths of 10 mm, 15 mm and 20 mm. This study analyzes the effect of variations in the volume fraction and fiber length of coconut coir with a polyester matrix on tensile testing using the Taguchi method. This tensile test was carried out using the ASTM D638 standard with the hand lay-up method. Factors that affect the tensile strength of coco fiber are volume fraction and fiber length. The combination of levels of factors that produce the average value and variance of the tensile strength of coconut coir fiber, namely the volume fraction factor (B) level 1, namely the volume fraction of 3% with a value of 30.933 and the fiber length factor (A) level 2, namely the fiber length of 15 mm with the most optimum value of 29.633.

The effect of low viscous coir fiber resin composite immersion time on composition dissolution

Background: E glass fiber dental is a fiber that is often used in dentistry. The availability of E glass fiber in Indonesia is still very limited. Various types of non-dental glass fiber materials are found in the market as engineering materials with relatively cheap prices so that they are expected to be used as an alternative to E glass fiber dental, which one of is coconut fiber. The composition of non-dental glass fiber is almost the same as that of dental E glass fiber. The composition affects the mechanical properties and chemical properties of the fiber. Glass fiber compositions such as Na2O and K2O will increase water resistance. 
 Method: This study was conducted using a post test only control group design. The material used in this study was a composite of coconut coir fiber. The subjects of the coco fiber composite were divided into 4 groups for solubility test based on ISO 4049. The results obtained were analyzed using one-way ANOVA (p = 0.000). The results showed the lowest mean component solubility (%) was in the coconut fiber composite group A (0.476±0.03) and the highest yield was in the coco coir fiber composite D (0.6±0.01). 
 Results: The results of the one-way ANOVA test showed a significant difference in the coco fiber composite in the solubility of the components (p

EFFECT OF ADDITION RAMIE AND COCONUT COIR FIBERS WITH DIFFERENT CONCENTRATIONS ON TENSILE STRENGTH OF ACRYLIC DENTURE BASE

Background: Acrylic denture base material has advantages such as good aesthetics, ease of repair, and affordable price, but this denture has mechanical properties, one of which is low tensile strength so fractures often occur during use. Utilization of natural fibers such as ramie (Boehmeria Nivea) and coconut coir (Coco Nucifera L) can be used as an alternative reinforcement for acrylic denture bases. Purpose: To determine the effect of adding ramie fiber and coconut coir fiber at different concentrations on the tensile strength of the acrylic denture base. Method: This study used a laboratory experimental method with a flat dumbell-shaped specimen with a size of 75 × 10 × 3 mm based on ISO 527-1 (2019). The specimens consisted of 42 plates which were divided into 7 groups, namely 6 specimens each group without fiber addition (control), with the addition of ramie fiber 1%, 2%, 3%, and the addition of coconut coir fiber 1%, 2%, 3%. Tensile strength testing using Universal Testing Machine (UTM), data were analyzed by One-way ANOVA test and Post Hoc LSD test. Result: The 3% ramie fiber addition group had the highest tensile strength (76.47 MPa), the 1% coconut coir fiber addition group had the lowest tensile strength (58.91 MPa). There was a significant difference in the results of the control group's tensile strength test and the addition of 3% ramie fiber and 1% coconut coir fiber (p-value < 0.05). Conclusion: The greater the concentration of ramie and coconut fiber additions, the higher the tensile strength value, although the tensile strength value in the coconut fiber addition group was lower than the control group and ramie fiber addition.

Sustainable and photoresponse triboelectric nanogenerators based on 2D-gC3N4 and agricultural wastes

Two bio-friendly and photoactive triboelectric nanogenerators (TENG) are introduced, employing sustainable and biocompatible materials as functional components. The TENGs utilize corn husk and coconut coir fibers as the positive layers and incorporate two-dimensional graphitic carbon nitride (g-C3N4) nanosheets as negative layers. Upon simple biomechanical forces, the optimized devices fabricated from corn husk and coconut fibers produce a maximum output voltage of 630 V and 581 V, respectively. Under short-circuit conditions, the measured current was approximately 0.79 mA for corn husk-TENG and 11.47 mA for coconut fibers-TENG. Also, the maximum output power of 131 mW and 1980 mW were achieved over a 2 × 2 cm2 area of corn husk-TENG and coconut fibers-TENG. The TENGs were also tested under blue commercial lights and UV light, and an increase of approximately 1.5 times was observed in the output voltages of both TENGs under UV light. These g-C3N4-based TENGs perform superior under UV illumination and can be used as nanogenerators and active photosensors. This paper proposes two eco-environmentally friendly and robust electronic devices for energy harvesting and photo-sensing applications based on two agricultural wastes, corn husk, and coconut coir fibers.