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Piezoelectric materials convert mechanical energy into electrical energy, acting as renewable energy sources. As smart materials, they respond to environmental changes by altering their properties. When pressure is applied, their structure separates positive and negative charge centers, producing opposite charges on crystal surfaces. This generates an electric field and a measurable potential. Wood, a natural material, also exhibits piezoelectric behavior. The piezoelectric effect of wood was first discovered by Russian scientists in 1940–1950. Then, in 1955, Fukada analyzed both the direct and inverse piezoelectric effect of wood and scientifically proved that this natural material has piezoelectric properties. Since then, much research has been done on the piezoelectric effect of wood. Research conducted between the 1960s and 1990s contributed to a deeper understanding of the piezoelectric properties of wood. Since the 2000s, various methods have been developed to enhance wood's piezoelectric performance using modern research techniques and advanced analysis. These studies improve the understanding of wood's piezoelectric properties and their potential applications. The research presents a chronological review of scientific studies from the discovery of the piezoelectric effect of wood to the present day. In addition, the piezoelectric and electric potential behavior obtained from planted trees and academic studies on the energy generation purposes of wooden structures are comprehensively examined. Wood's potential as a natural piezoelectric material is significant, particularly for renewable energy sources and smart material technologies. Optimizing its piezoelectric properties aims to enhance energy harvesting, sensor performance, and other advanced technological applications. [ABSTRACT FROM AUTHOR]

Mayonnaise, a high fat emulsified food, always contains egg yolk as a source of emulsifier. Lowering fat content and restricting use of egg yolk are promising ways to enhance nutritive profile and attraction to vegan trend. This work aimed to prepare fat-reduced eggless mayonnaise with good physicochemical stability using pea protein isolate (PPI) in combination with cellulose crystals as a co-emulsifier. Emulsifying property of Okara cellulose crystals (OC) and modified OC using gallic acid (OCG) was investigated. The cellulosic materials possessed effective emulsifying property, particularly at increased concentration. The present work suggested that acid-aided hydrolysis could improve emulsifying property of PPI. Then, the acid-modified PPI (aPPI) together with OC or OCG were employed at different ratios as a co-emulsifier for fat-reduced eggless mayonnaise preparation. The co-emulsifier could improve dispersibility and rheological property of the mayonnaise effectively. In addition, the cellulosic materials improved oxidative stability of the mayonnaises, particularly for OCG. This behavior might be expected since a steric hindrance effect of the interfacial films of co-emulsifier, in addition to antioxidant capacity of OCG. Thus, the innovative addition of the dual modes of emulsifying and antioxidant actions could be used to improve physicochemical stability and reduce fat content of eggless mayonnaise.

X-ray scattering methods allow efficient characterization of cellulosic materials, but interpreting their results is challenging. By creating molecular dynamics models of cellulose microfibrils and calculating the scattering from them, we investigated how different properties of the structures affect their scattering intensities. We studied the effects of hemicelluloses and crystal size on small-angle and wide-angle X-ray scattering (SAXS, WAXS). Microfibril models with and without surface-bound hemicelluloses were built based on the chemical composition of spruce secondary cell walls. The effect of fibril size was investigated by comparing the scattering from fibrils with 14 to 40 cellulose chains. The hemicelluloses appeared in the SAXS region as an increase in the fibril radius and as a clear contribution of a shell around the fibril. The hemicelluloses also increased the crystal size as determined from the broadening of the 200 diffraction peak of cellulose I β . The SAXS and WAXS analysis provided consistent estimates for the size of the microfibrils, and their special features and challenges were discussed. In particular, the results of 18-chain microfibrils were consistent with prior experimental results. Carrying out the simulations in wet and dry environments had the most pronounced effect on fibrils with a hemicellulose coating. Twisting of the fibril had very little impact on most properties, except for a minor effect on the WAXS peaks. The results allow for more correct interpretation of experimental scattering results, leading to more accurate descriptions of microfibril structures in natural and processed cellulosic materials. [ABSTRACT FROM AUTHOR]

Okara, a major by-product in the processing of soybean-based products, is always reserved for low-value purposes. However, okara consists of cellulose that can be practically employed in the preparation of cellulose crystals. In this work, cellulose crystals were prepared from okara under different conditions (acid contents and reaction times) to maximize their emulsifying ability. The functional property of the cellulose crystals tended to improve with increasing acid content and reaction time of the hydrolysis. Cellulose crystals with potent emulsifying capacity were prepared at an okara: acid ratio of 1:10 and a hydrolysis time of 45 min. The emulsifying activity of the okara cellulose crystals (O–CC) was then explored in solutions with varying pH and salt concentrations. The surface charge on O–CC crucially affected the dispersibility of the O–CC stabilized emulsion, as evidenced by the inferior emulsion stability when the surface charges on O–CC were suppressed. The O–CC stabilized emulsion was tolerant to NaCl addition, supposedly because the particle size and surface activity of O–CC were sufficient to provide a steric barrier against drop coalescence. [ABSTRACT FROM AUTHOR]

Empty fruit bunches are a lignocellulosic waste byproduct of palm oil production. As is typical for many such fibres from a waste stream, the utilization of these fibres as material, or source of carbon for the production of bioethanol, is hampered by a poor knowledge of the solid state polymer nanostructure where a long fibrous crystalline polymer is embedded in an amorphous matrix. In this study we characterize the bionanocomposite structure, long fibrous cellulose crystals in an amorphous matrix, with X-ray scattering and solid state NMR of empty fruit bunches. Our aim is to provide a structural basis to understand the processing of fibres and their degradation. X-ray scattering both at small and wide angles provided a complementary perspective on the fundamental unit of cellulose organization, long fibrous crystallites called microfibrils: the spiral angle of microfibrils around fiber axis; and the organization of individual cellulose chains in the crystallites. Solid state NMR provides structural and compositional perspectives on the amorphous component. Some general comments on the complementary use of these two techniques in biofibers are given. [ABSTRACT FROM AUTHOR]

Currently, the cultivation of lactic acid bacteria is mainly carried out by improving the fermentation process and culture conditions, which was difficult to ensure the survival quantity and culture efficiency. The primary purpose of this work was to construct water-in-water (W/W) Pickering emulsion as a microculture for probiotics. The W/W Pickering emulsion consisting of maltodextrin (MD) and hydroxypropylmethylcellulose (HPMC) was constructed by using microcrystal celluloses (MCC) as the Pickering stabilizers. The effects of MCC concentration, NaCl concentration, MRS broth concentration, and pH value on the formation and stability of W/W Pickering emulsion have been investigated. The stability of W/W Pickering emulsions was driven by the electrostatic repulsion provided by the MCC. The stability of the emulsion was reduced by increasing NaCl and MRS broth concentrations, primarily because their charge shielding effect weakened the electrostatic repulsion between the MCC particles. The W/W Pickering emulsion had higher stability in a weakly acidic environment. The results from another trial revealed that Lactobacillus helveticus CICC 22,536 had little influence on the stability of the W/W Pickering emulsion when it was encapsulated in the emulsion. Moreover, Lactobacillus helveticus was able to be cultured in the emulsion, and the numbers of Lactobacillus helveticus after being cultured for 16 h were increased to 1.1 × 109 CFU/mL. These findings indicated that the W/W Pickering emulsion provided a new approach and an attractive platform for the cultivation of probiotic bacteria. [Display omitted] • W/W Pickering emulsion stabilized by using MCC had been constructed. • W/W Pickering emulsion could be used to encapsulate Lactobacillus helveticus. • The W/W Pickering emulsion was a fascinating microculture apparatus for cultivation of Lactobacillus helveticus. [ABSTRACT FROM AUTHOR]

Cellulose is skeletal material of sclerenchymatous cell wall. The relationship between the structure of cellulose and the mechanical properties of the cell wall was studied in the research. Samples of cells were from different position at the cross section (rind, near rind, and core) of different position along sugarcane stem (top, middle, and base) during 1st, 2nd and 3rd growth stages (respectively in June, September, and December). The size of cellulose crystals, its microfibril angle and distribution in S2, and the indentation modulus of S2 were measured by X-ray diffraction, laser confocal Raman microspectroscopy, and nanoindentation tests respectively. The results showed that the microfibril angle increased during 1st to 3rd stage and from rind to core. The size of cellulose crystal decreased from rind to core. Both of them changed little from base to top. By the Raman spectral curve, the spectral intensity of rind in the 3rd growth stage was the highest. During 1st to 3rd stage, the distribution intensity of cellulose crystals at the rind and core firstly decreased and then increased, and it changed conversely at the near rind. The crystal size and microfibril angle strongly correlated, while the cellulose distribution weakly correlated, with the modulus.

Oligomeric cellulose with an average degree of polymerization of 7.68 and a polydispersity of 1.04 has been fractionated using solution processes. Three fractions have been obtained through initial dissolution, subsequent crystallization, and solvent precipitation, respectively. The resulting oligocellulose fraction has an average degree of polymerization of 7.70 and a polydispersity of 1.01, respectively. Cellulose IV 2 crystals form in the oligocellulose fraction, and reversibly transform to II and back to IV using simple solvents.

• The process-structure-property relationships of tunicate celluloses were analyzed. • The crystalline cellulose fibers produced nanolayered films by nematic behaviors. • The film could be engineered in wide ranges of mechanical and thermal properties. • Our cellulose films can be applied for the high-performance eco-substrates. Tunicate cellulose nanofibers (CNFs) have received widespread attention as renewable and eco-friendly engineering materials because of their high crystallinity and mechanical stiffness. Here, we report the effects of disintegration process conditions on structure-property relationships of tunicate CNFs. By varying the hydrolysis time, we could establish a correlation between crystallinity of the CNFs with linearity and stiffness, which produces different molecular ordering within their nanostructured films. Despite having identical raw materials, tensile strength and thermal conductivity of the resulting layered films varied widely, ranging from 95.6 to 205 MPa and from 1.08 to 2.37 W/mK respectively. Furthermore, nanolayered CNF films provided highly anisotropic thermal conductivities with an in- and through-plane ratio of 21.5. Our systematic investigations will provide general and practical strategies in tailoring material properties for emerging engineering applications, including flexible paper electronics, heat sink adhesives and biodegradable, implantable devices. [ABSTRACT FROM AUTHOR]

The parameters of the alkaline fractionation process were investigated and optimized using a statistical analysis method to simultaneously remove hemicellulose and ash from rice husk (RH) concomitantly. After the alkaline fractionation process, the residual solid contained high cellulose, and the recovery yield of hemicellulose was enhanced in the fractionated liquid hydrolyzate. The hemicellulosic sugar recovery yield (71.6%), de-ashing yield (>99%), and lignin removal (>80%) were obtained at the reaction conditions of 150 °C of temperature, 40 min of reaction time, and 6% (w/v) of NaOH concentration. Subsequently, nano-structured silica was synthesized using black liquor obtained as a by-product of this fractionation process. For the production of nano-structured silica, it was observed that the pH of a black liquor and the heat treatment temperature significantly influenced the textural properties of silica product. In addition, the two-stage bleaching of solid residue followed by colloid milling for the production of high value-added CNF with was attempted. As a result, in addition to 119 g of fermentable sugar, 143 g of high-purity (>98%) silica with a surface area of 328 m2g−1 and 273.1 g of high-functional CNF with cellulose content of 80.1% were simultaneously obtained from 1000 g of RH. [ABSTRACT FROM AUTHOR]