The effect of argon (Ar) and oxygen (O₂) gases as well as the treatment times on the properties of modified bamboo fibers using dielectric barrier discharge (DBD) plasma at generated power of 180 W were investigated. The plasma treatment of bamboo fibers with inert gases leads to the generation of ions and radicals on the fiber surface. Fourier transform-infrared spectroscopy (FTIR) confirmed that the functional groups of lignin and hemicellulose were reduced owing to the removal of the amorphous portion of the fibers by plasma etching. X-ray diffraction analysis (XRD) results in an increased crystallinity percentage. X-ray photoelectron spectroscopy (XPS) results showed the oxygen/carbon (O/C) atomic concentration ratio increased with increasing treatment time. The fiber weight loss percentage increased with increased treatment time. Scanning electron microscopy (SEM) images showed that partial etching of the fiber surface led to a higher surface roughness and area and that the Ar + O₂ gas plasma treatment provided more surface etching than the Ar gas treatment because of the oxidation reaction of the O₂ plasma. The mechanical properties of fiber-reinforced epoxy (FRE) matrix composites revealed that the F_(tr)RE-Ar (30) samples showed a high tensile strength, whereas the mechanical properties of the F_(tr)RE-Ar + O₂ sample decreased with increased treatment time.

Global warming is a vital issue addressed to every sector worldwide, including the construction industry. To achieve the concept of green technology, many attempts have been carried out to develop low-carbon footprint products. In the construction sector, Autoclaved Aerated Concrete (AAC) has become more popular and been manufactured to meet the construction demand. However, errors from manufacturing process accounted for approximately 3 to 5% of the AAC production. The development of AAC waste as lightweight aggregate in concrete is one of the potential approaches which was extendedly studied in this paper. The results showed that the compressive strength of AAC-LWA concrete was decreased with an increase in volume and coarse size. The optimum mix proportion was the AAC aggregate size of 1/2′′ to 3/8′′ with 20 to 40% replacement to normal weight aggregate. Internal curing by AAC-LWA was also observed and found to provide sufficient water inside the specimens, leading to an achievement in higher compressive strength. The main goal of this study is not only utilising unwanted wastes from industry (recycling of waste materials) but also building up a new knowledge of using AAC-LWA as an internal curing agent as well as the production of value-added lightweight concrete products.

Bamboo cellulose fiber (BF)-reinforced epoxy (EP) composites were fabricated with BF subjected to plasma treatment using argon (Ar), oxygen (O₂), and nitrogen (N₂) gases. Optimal mechanical properties of the EP/BF composites were achieved with BFs subjected to 30 min of plasma treatment using Ar. This is because Ar gas improved the plasma electron density, surface polarity, and BF roughness. Flexural strength and flexural modulus increased with O₂ plasma treatment. Scanning electron microscopy images showed that the etching of the fiber surface with Ar gas improved interfacial adhesion. The water contact angle and surface tension of the EP/BF composite improved after 10 min of Ar treatment, owing to the compatibility between the BFs and the EP matrix. The Fourier transform infrared spectroscopy results confirmed a reduction in lignin after treatment and the formation of new peaks at 1736 cm⁻¹, which indicated a reaction between epoxy groups of the EP and carbon in the BF backbone. This reaction improved the compatibility, mechanical properties, and water resistance of the composites.

Poly(lactic acid) was melt-blended with epoxy resin without hardener and chitosan (CTS) to prepare modified PLA (PLAEC). Epoxy resin 5% and CTS 1–20% (wt/wt) were incorporated into PLA during melt mixing. PLAEC was melt-blended with an epoxidized natural rubber (ENR) 80/20 wt. The PLAEC CTS 1% blended with ENR (PLAEC1/ENR) showed a high tensile strength (30 MPa) and elongation at break (7%). The annealing process at 80 °C for 0–15 min maintained a tensile strength of approximately 30 MPa. SEM images of the PLAE/ENR blend showed phase inversion from co-continuous to ENR particle dispersion in the PLA matrix with the addition of CTS, whereas the annealing time reduced the hole sizes of the extracted ENR phase due to the shrinkage of PLA by crystallization. Thermal properties were observed by DSC and a Vicat softening test. The annealing process increased the crystallinity and Vicat softening temperature of the PLAEC1/ENR blend. Reactions of −COOH/epoxy groups and epoxy/−NH₂ groups occurred during PLAE and PLAEC preparation, respectively. FTIR confirmed the reaction between the −NH₂ groups of CTS in PLAEC and the epoxy groups of ENR. This reaction increased the mechanical properties, while the annealing process improved the morphology and thermal properties of the blend.

In this study, we investigated the behaviors of epoxy composites reinforced with bamboo (BF) and hemp (HF) fibers. Both fibers were treated using dielectric barrier discharge (DBD) plasma for various durations (2.5 to 20 min). Epoxy resin (ER) was mixed with BF or HF with and without plasma treatment. The Fourier-transform infrared spectra of the plasma-treated fibers showed an enhanced peak intensity of carboxyl groups. ER/BF treated for 20 min exhibited a high tensile strength (up to 56.5 MPa), while ER/HF treated for 20 min exhibited a more significant increase in elongation at break (6.4%). Flexural tests indicated that the plasma treatment significantly improved the flexural strength of the hemp composites (up to 62.2 MPa) compared to the bamboo composites. The plasma treatment increased the fiber surface roughness and interfacial bonding in both composites. The thermal stability and wettability were improved by the DBD plasma treatment. The DBD plasma treatment enhanced the interfacial adhesion between fibers and ER matrix, which improved the mechanical, thermal, and wettability properties of the composites.

This study investigates the microstructural characterization of cellulose nanocrystals (CNC) and microcellulose (MC) extracted from bamboo fibers (Bambusa longispatha) and their potential as reinforcement agents in ordinary Portland cement (OPC) composites. CNC with a mean particle size of 29.3 nm and MC with a mean size of 14.6 × 10³ nm were incorporated into OPC at varying concentrations (0.1%, 0.2%, 0.4%, and 0.6% by cement mass). The compressive strength analysis revealed that increasing MC content led to a decrease in strength, with reductions ranging from 8.8% to 25.9% relative to the control OPC, while the CNC-enhanced composite at 0.4% achieved the highest compressive strength of 43.2 MPa. Flexural strength analysis indicated a minor increase in strength with MC addition (from 7.5 MPa to 8.1 MPa), while CNC addition at 0.1% improved flexural strength to 8.2 MPa but declined with higher concentrations. SEM and stereo microscopy demonstrated MC and CNC dispersion and highlighted microstructural differences, including pore distribution in the composites. XRD analysis showed increased crystallinity for CNC composites compared to pure OPC, with the highest crystallinity index of 52.2% observed at 0.4% CNC. This study highlights that CNC at specific concentrations can enhance OPC mechanical properties, while higher MC and CNC additions may impact strength properties variably due to their microstructural integration and crystallinity. These findings support the potential for bamboo-derived cellulose materials in enhancing cementitious composite performance.