Bamboo Samples Research Articles

Quantifying the heavy metal risks from anthropogenic contributions in Sichuan panda (Ailuropoda melanoleuca melanoleuca) habitat

Heavy metals (HM) are ubiquitous in environments, and HM pollution has become a severe global crisis. Previous studies have identified HM levels in Qinling panda habitats but their levels and the associated risks in Sichuan panda habitats are still unknown. Risk-based conservation management is in urgent need and should rely upon identifying risk distributions, quantified risk-source apportionment and collaborative governance. We carried out research in Sichuan panda (Ailuropoda melanoleuca melanoleuca) habitats taking soil, bamboo, and water samples from three different areas (nature reserves, potential habitats, and surrounding regions) of five mountains. The concentrations of HM in the soil were higher than those in bamboo, but both exceeded the background or national standards to varying degrees, suggesting long-term pollution and multi-element contamination. Regional and geographical distribution differences revealed a positive correlation between intensity of human activities and HM pollution. HM contaminants observed in the Sichuan panda habitats, based on their sources, were categorized into coal combustion (34%), industry (44%), and traffic (22%). In particular, our results showed the northern and southern parts of habitat were of highest concern, as they had environmental conditions that could be harmful to the health of giant pandas. Coupling models applying positive matrix factorization model/risk were used to quantify source contributions to various risk types, which was based on real-time monitoring and served as a positive role in multi-step process for developing countermeasures, with the goal of collaboratively reframing the vision and governance of panda conservation in order to incorporate regional disparities.

Near infrared spectroscopy to evaluate change in color and chemical composition in heat-treated bamboo

This study investigated the feasibility of using near infrared spectroscopy technology to predict color and chemical composition in the heat-treated bamboo processing industry. The quantitative presentations of the changes in the chemical components were discussed using the difference spectra method of the 2nd derivative NIR spectra of the heat-treated bamboo samples. Then, the relationships between the color changes of the heat-treated bamboo and its near infrared spectra were constructed using the changes in the chemical components of the bamboo samples during the heating process. The prediction of color and chemical composition of both the outer and inner sides of the heat-treated bamboo surface were constructed using partial least squares regression method combined with a leave-one-out cross-validation process. Then, the results were validated by independent sample sets. The proposed prediction models were found to produce high r2P (above 0.93), RPD (above 3.13), and low RMSEP for both the outer and inner sides of the heat-treated bamboo samples. These studies’ results confirmed that the proposed models, especially outer side models, were perfectly suitable for the in-process inspections of the color and chemical content changes of heat-treated bamboo.

Cassava- and bamboo-derived carbons with higher degree of graphitization for energy storage

Biomass-derived carbons are among the most promising candidates for large-scale electrochemical-energy-storage devices owing to their low cost, sustainability and widespread resources. Herein, the authors report a simplistic synthesis process for preparing two types of biomass carbons derived from cassava stalks and bamboo consisting of direct pyrolysis of the ground samples at 750°C for 4 h. The electrochemical performances of the prepared biomass carbons are investigated in supercapacitors and lithium-ion battery (LIB) systems. Both the cassava and bamboo samples possess a high graphitization degree and good surface wettability as demonstrated by X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. As a supercapacitor electrode, cassava-derived carbons show the best performance with a maximum specific capacitance of 212 F/g and capacity retention of 95% after 2000 cycles. Moreover, as an electrode material for LIBs, cassava-derived carbons demonstrate the highest charge capacity of 357 mAh/g (at 100 mA/g), which stabilizes at 254 mAh/g. This approach shows great potential to achieve advanced electrode materials from low-cost, green and industrial-grade production of biomass-derived carbon materials by simple synthesis for advanced energy-storage applications in the future compared with conventional approaches.

Compressive and tensile strength of bamboo species

Asia is the continent with the largest bamboo population int the world, so bamboo is a popular construction material in Asian countries such as China, India, and also Indonesia. There are 145 species of bamboo species that grow in Indonesia, and in the eastern region of Sumatera Utara (Deli Serdang, Langkat, and Sedang Bedagai district), 13 species can be found. But in this region, the use of bamboo in construction is limited, due to lack of knowledge about the strength of local bamboo. This study is conducted to determine the mechanical properties, namely the compressive and tensile strength of bamboo species that grow in the region. The results obtained are the preliminary data to conduct further studies to utilize bamboo in this region as a construction material. To obtain the compressive and tensile strength, compression and tension test are carried out based on ISO 22157 standard and performed on node and internode sections of bamboo samples. The result of this study shows that for a compression test, the compressive strength for node and internode samples did not show significant differences. But in the tension test, the internode tensile strength significantly higher than the node.

Understanding fire growth for performance based design of bamboo structures

This paper analyses the different parameters governing fire growth and presents the results obtained for laminated bamboo samples produced from the species Phyllostachys pubescens “Moso”. Parameters such as critical heat flux, temperature for ignition, thermal inertia, mass loss rate and heat release rates are studied herein. Last, the ignition parameters of laminated bamboo are contrasted against the available information on bamboo and commonly used timber products. Results show that overall, laminated bamboo show higher critical heat flux for ignition, ignition temperature, and thermal inertia when compared to timber species.

Study on the Properties of Transparent Bamboo Prepared by Epoxy Resin Impregnation.

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.

Influence of hornification on the physical and flexural properties of Moso bamboo

This work aims to investigate experimentally the improvements on the physical and flexural properties of Moso bamboo species (Phyllostachys pubescens) associated to the hornification phenomenon, widely used as a treatment in wood pulps or paper to reduce porosity, absorption capacity and water retention of the fibers, as well as to increase their stiffness. To accomplish this task, bamboo samples subjected up to ten wetting and drying cycles had their flexural characteristics such as stiffness, strength, neutral axis, deflection at failure and through-thickness shear modulus compared with untreated samples. The moisture content was monitored during cycles and image analysis was performed to determine the distribution of vascular bundles throughout the wall thickness of the culm’s cross-section. The experimental program showed a reduction in water retention capacity of bamboo and in the deflection at failure, as well as an increment in the modulus of elasticity up to 70% after treatment. The tests also reveal a major influence of shear deformation on the overall deflection and appropriate strain measurement techniques must be used for a more accurate moduli determination. Finally, a simplified micromechanical approach was used along with fiber content distribution to estimate the influence of hornification on the moduli under compression and tension of the constituents.

Environmental Durability Enhancement of Natural Fibres Using Plastination: A Feasibility Investigation on Bamboo.

Natural fibers are gaining wide attention due to their much lower carbon footprint and economic factors compared to synthetic fibers. The moisture affinity of these lignocellulosic fibres, however, is still one of the main challenges when using them, e.g., for outdoor applications, leading to fast degradation rates. Plastination is a technique originally used for the preservation of human and animal body organs for many years, by replacing the water and fat present in the tissues with a polymer. This article investigates the feasibility of adapting such plastination to bamboo natural fibres using the S-10 room-temperature technique in order to hinder their moisture absorption ability. The effect of plastination on the mechanical properties and residual moisture content of the bamboo natural fibre samples was evaluated. Energy dispersive x-ray spectroscopy (EDS) and X-ray micro-computed tomography (Micro-CT) were employed to characterize the chemical composition and 3-dimensional morphology of the plastinated specimens. The results clearly show that, as plastination lessens the hydrophilic tendency of the bamboo fibres, it also decreases the residual moisture content and increases the tensile strength and stiffness of the fibers.

Variability of Physical and Chemical Properties of TLUD Stove Derived Biochars

Biochar is a carbon-rich organic material, obtained by the thermochemical conversion of biomass in an oxygen-limited environment, used as a soil amendment to stimulate soil fertility and improve soil quality. There is a clear need in developing countries for access to low cost, low technology options for biochar production, for example, top-lit updraft (TLUD) stoves, which are popular and spread worldwide. However, TLUD biochars are inevitably very variable in their properties for a variety of reasons. We present laboratory triplicate tests carried out on TLUD biochars obtained from waste pinewood and a Guadua bamboo. Analyzed properties include specific surface area (A-BET), porosity, skeletal density, hydrophobicity, proximal and elemental composition, cation exchange capacity (CEC), relative liming capacity and pH. SEM images of the bamboo and wood biochars are compared. The biochars were mixed with composted human excreta at 5% and 10% biochar content, and available water content (AWC) was analyzed. Operating temperatures in the TLUD were recorded, showing different behaviors among the feedstocks during the process. Differences in operating temperatures during charring of the bamboo samples seem to have led to differences in A-BET, hydrophobicity and CEC, following unprecedented trends. For the mixtures of the biochars with compost, at 5% biochar no significant differences were observed for AWC. However, in the 10% biochar mixtures, bamboo biochar showed an unexpectedly high AWC. Overall, variations of chemical and physical properties between bamboo biochars were greater, while pinewood biochars showed similar properties, consistent with more homogeneous charring temperatures.

Prediction and Analysis of Bamboo heating value Near Infrared Spectroscopy Based on Competitive Adaptive Weighted Sampling Algorithm

China is one of the largest bamboo producers in the world. Bamboo has the characteristics of large biomass and fast growth, which is considered to be an ideal biomass energy source. In order to satisfy the needs of modern biomass conversion processes, there is an urgent need to develop a method for rapidly determining the heating value of bamboo. In this paper, the spectral data of 80 bamboo samples were obtained by Near-Infrared Spectroscopy (NIRS), and then the heating value of bamboo was measured by conventional methods. Through the analysis of bamboo sample data, the Partial Least Squares Regression (PLSR) algorithm, and the Competitive Adaptive Weighted Sampling and PLSR combination (CARS-PLSR) algorithm were used to establish the relationship between spectral data and heating value. The results show that the number of characteristic wavelengths obtained by the CARS algorithm is 24, while the wavelength of the original medium-long wavelength band is 1320, which reduces the number of wavelengths by 98.18%, and greatly reduces the data size. In addition, the selected feature wavelengths can better reflect the key information of the bamboo spectrum, which have a better model effect than the unscreened model. In this study, the heating value index (R2c, R2p, RPD) of the CARS-PLSR model was 0.97, 0.98, and 6.22, respectively. The bamboo heat generated PLSR model was established by using the characteristic wavelength selected by CARS algorithm, which greatly simplified the complexity of the model and improved the predictive ability of the model.

Effect of Alkaline Copper Quaternary Type D on Color Retention, Mold Resistance, and Surface Physicochemical Characterization of Neosinocalamus affinis Bamboo

Abstract The effect of alkaline copper quaternary type D (ACQ-D) treatment on color retention, mold resistance, and surface physicochemical characterization of Neosinocalamus affinis bamboo was analyzed. The results showed that a treatment of 0.25 percent ACQ-D solution combined with pretreatment of potassium hydroxide and sodium dodecyl sulfate mixed aqueous solution can achieve a desired green color on the bamboo surface. The mold test result revealed that the treated bamboo samples had better mold resistance than samples only treated with a mold inhibitor. The thermogravimetric–Fourier-transform infrared spectroscopy analysis of the treated and the control samples indicated that the chemical structure of the surface was slightly modified, e.g., silicon was almost completely removed, which enhanced liquid permeability. The dilute ACQ-D solution combined with a proper pretreatment process could retain the favorable green color of bamboo and also improve mold resistance by slightly modifying the surface chemistry.

Isoconversional kinetics of pyrolysis of vaporthermally carbonized bamboo

With the rapid development of the current society, the world faces energy shortages, greenhouse gases and ecological rings. Issues such as environmental protection have become increasingly prominent. A new method was developed to produce vaporchar using bamboo as starting materials via a VTC. Bamboo and the vaporchar were characterized by scanning electron microscope and FTIR to indicate the transformation in their morphologies and chemical structure, respectively. Afterwards, a comparative study in relation to the thermal behavior and pyrolysis characteristics for the vaporchar and the raw bamboo was investigated. FTIR spectra of raw bamboo and semi-char of bamboo vaporchar of at different final temperature samples was coupled with the TGA to analyze the chemical structure changed. Then, the relationship between the activation energy and various conversion rates of bamboo and vaporchar were evaluated by the methods of KAS and FWO. It shows the activation energy of bamboo is about 88.01–144.13 kJ/mol and 88.33–140.65 kJ/mol and that of VTC is about 142.19–355.96 kJ/mol and 139.31–360.71 kJ/mol for FWO and KAS, respectively. Compared with the bamboo sample, the activation energies of VTC obtained at 12 h are higher than that of raw bamboo with the increasing conversion level.

Thermal behaviour of laminated bamboo structures under fire conditions

SummaryA series of experiments have been conducted to measure the in‐depth heating of laminated bamboo samples subjected to heat fluxes of 5, 10, 30, and 60 kW/m2, either perpendicular or parallel to the grain. These heat fluxes were chosen to induce different phenomena within the material—from inert heating to moisture evaporation, pyrolysis, oxidation, and flaming—so that the effects of these can be isolated and evaluated separately by simple heat‐transfer models. Moisture migration along the fibres becomes a critical factor when bamboo is heated parallel to the grain, resulting in increased convective heat transfer to deeper parts of the material and an accumulation of moisture in depth that accentuates the endothermic plateau in the temperature profiles around 100°C. Average charring rates for 60 minutes of exposure under 60 kW/m2 were 0.74 and 0.70 mm/min for perpendicular and parallel heating, respectively. The thickness of the heated layer was much larger for parallel heating due to moisture migration, which is less significant perpendicular to the grain. Inert heat diffusion is a good approximation at heat fluxes of 5 and 10 kW/m2, but exothermic oxidation reactions become critical above 400°C and must be included in future models.

Mold resistance of bamboo treated with copper complexes-grafted silica gel and its microdistribution in treated bamboo

Bamboo is readily discolored by mold fungi, which greatly limits its applications. An effective antifungal agent, copper(II) chloride (CuCl2)-grafted silica gel, was prepared by a sol–gel process using tetraethoxysilane (TEOS)/3-aminopropyltriethoxysilane (APTES) mixtures. The elemental composition and the chemical combinations of homogeneous sol mixture (HSM) and bamboo were determined via Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectrometry (SEM–EDS). The mold resistance of bamboo treated with HSM, alkaline copper quat (ACQ), chromated copper arsenate (CCA), and purified water was characterized by an indoor mold test. The micro-morphology of bamboo treated with HSM was investigated using scanning electron microscopy (SEM). HSM penetrated into the bamboo vessels, and formed xerogels, which was able to coordinate copper(II) cations. SEM–EDS investigations suggest that Si–O–Cu linkages may be formed through an exchange reaction between silanol groups and copper complexes. The bamboo samples treated with HSM showed highly efficient mold resistance due to a good penetration of HSM. Furthermore, no fungal hyphae were found in the structure of HSM-treated bamboo after a 5-week mold test. The copper complexes grafted to silica gel developed in this work provide an efficient antifungal agent for a wide range of potential applications in bamboo protection.

Effects of Liquid Hot Water Combined with 1, 4-Butanediol on Chemical Composition and Structure of Moso Bamboo.

The effects of liquid hot water combined with 1, 4-butanediol (LHW-BDO) on the chemical composition and structure of moso bamboo were investigated. The structure changes of moso bamboo fibers were characterized by infrared spectroscopy, X-ray diffraction, and electronic scanning electron microscopy. The results showed that the delignification rates of 1, 4-butanediol (BDO) and LHW-BDO pretreatment methods were at the same level (91.42-93.08%). However, compared with BDO pretreatment, the cellulose content in solid residue after LHW-BDO pretreatment was increased by 17.06% with a recovery rate of 75.68%, while the hemicellulose removal rate increased by 115.33% and reached 50.34%. After LHW-BDO pretreatment, the intramolecular hydrogen bonds, intermolecular hydrogen bonds, methylene bonds, and aromatic ether bonds of the fibers were broken, which contributed to the depolymerization and separation of cellulose, hemicellulose, and lignin molecules. However, LHW-BDO pretreatment does not destroy the β-glycoside bond which links the glucose molecule inside the fiber molecule, which was also beneficial to the separation of cellulose. In addition, the amorphous zone of bamboo fibers was destroyed by the above treatments, and the fiber structure of bamboo samples mostly exists in crystalline form. The crystallinity of bamboo pretreated with LHW-BDO was increased by 32.15%. It can be found by scanning electron microscopy that the surface of the pretreated bamboo samples showed uniformly distributed bubbly protuberance.

Facile in-situ growth of Ag/TiO2 nanoparticles on polydopamine modified bamboo with excellent mildew-proofing

Bamboo with the outstanding properties, such as good mechanical strength, fast growth rate and low growth cost, is considered as one of utilitarian structural nature materials. But bamboo is easy to get mildewed resulting in disfiguration and fungi corrosion. In this work, a facile method was developed to improve the mildew-proofing capability of bamboo. Mussel-inspired polydopamine (PDA) with biomimetic adhesion function and highly active functional groups was employed to immobilize highly-dispersed Ag and TiO2 nanoparticles on the surface of bamboo via an in-situ growth method. Integrating the uniform PDA coating, photocatalytic function of TiO2 nanoparticles and bactericidal role of Ag nanoparticles, the mildew-proofing capability of bamboo is enhanced significantly. The results show a non-covalent interaction is more likely to account for the binding mechanism of PDA to bamboo. And the prepared bamboo samples show good photocatalytic performance and have excellent resistance leachability. Meanwhile, the mildew-proofing property of prepared bamboo sample was greatly improved.

Acoustic emission analysis of raw bamboo subjected to tensile tests

This work presents data analysis of the acoustic emission (AE) signals released by raw bamboo specimens subjected to monotonic tensile tests. Bamboo wood samples were extracted from the full culm of Bambusa Vulgaris species. A spectral analysis of the AE signals was conducted. It was found that the material suffers a significant plasticization before breakage of the culm’s inner wall. From this point and until the final breakage of the outer wall, an important increase of the center of gravity (CoG) of the signal spectrum was observed. AE signals with CoG above 200 kHz were associated with fiber breakage.

Preparation and properties of bamboo/polymer composites enhanced by in situ polymerization of furfuryl alcohol

The objective of this paper aimed to develop a novel method to prepare enhanced bamboo-based materials. Furfuryl alcohol (FA) was used as the modification agent with maleic anhydride (MA) as the catalyst. Different bamboo samples were prepared with different FA addition level (10 wt%, 20 wt% and 30 wt%). The furfurylated bamboo samples were characterized by confocal laser scanning microscopy (CLSM), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Moreover, the physical and mechanical properties including weight percent gain (WPG), water uptake (WU), thickness swelling (TS), modulus of rupture (MOR), and modulus of elastic (MOE) were investigated in detail. Additionally, the decay resistance of pristine and furfurylated bamboo samples was also investigated. The results showed that FA resins were incorporated into bamboo and polymerized within cell walls. The WPG, WU, and TS were dependent on FA addition level. When the FA addition level reached 30 wt%, the physical properties were all improved significantly. However, due to acidic MA as the catalyst, MOR of furfurylated bamboo samples was enhanced only 2.5% while MOE was weakened. The thermal stability and decay resistance of furfurylated bamboo were all enhanced significantly compared to pristine bamboo. Especially, furfurylated bamboo treated with 30 wt% FA achieved Class I Strong Decay Resistance (<10%) with 5.3% of mass loss.

Improvement of proximate data and calorific value assessment of bamboo through near infrared wood chips acquisition

In a previous study, a near infrared (NIR) spectroscopy model was developed using a spectra of ground bamboo samples. Although the previous report on ground bamboo described a good performance, operation in the power plant was found to be inconvenient due to preparation costs and labour required for the necessary preparation of ground samples. Thus, this study presents the comparison of the performance of an NIR model that was developed by direct scanning of bamboo chips to the previously developed model for ground samples. Special emphasis is put on the comparison of the spectral reproducibility. Bamboo chip models were developed based on PLS regression with variable selection methods in order to achieve the optimal model. The moisture content (MC) and ash content (A) of the developed bamboo chip models could be applied toward quality assurance. The volatile matter (VM) and fixed carbon (FC) models could be used for approximating predictions. The gross and net calorific value (GCV and NCV) models could be used for most applications. The root mean square (RMS) value of pre-treated spectra of different particle size had no statistically significant differences. The study’s findings indicate that the model developed using NIR spectroscopy protocol with wood chips spectra can be used as a classification tool and is an effective method for estimating bamboo chip energy quality. The big particle size of wood chips affect negatively the prediction model, however, it could be solved through spectral pre-processing technique, thus eliminating the need for grinding feedstock samples.

Synergistic effects of tung oil and heat treatment on physicochemical properties of bamboo materials

The search for green and sustainable modification method to produce durable bamboo materials remains a challenge in industry. Here, heat treatment in tung oil at 100–200 °C was employed to modify bamboo materials. Oil permeation and distribution in the structure of bamboo samples during heat treatment were explored. The synergistic effects of tung oil and heat treatment on the chemical, physical and mechanical properties of bamboo materials, and their mutual relationships were also investigated in detail. Results showed that the tung oil heat treated bamboo not only had an enhanced hydrophobic property and dimensional stability, improved fungi resistance, but also displayed good mechanical performance. Compared with the untreated sample, the water-saturated swelling reduced from 3.17% to 2.42% for the sample after oil heat treatment at 200 °C, and the contact angles of the sample after oil heat treatment at 200 °C can keep >100° after 300 s in radial direction. Such improvement can be attributed to changes of chemical components, increased crystallinity structure, and the formation of oily films inside or over the bamboo surface. Therefore, tung oil heat treatment can be a highly promising technology for bamboo modification in the industry.