Nanocellulose: a new ageless bionanomaterial

With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

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Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

The main goal of this article is to provide an overview of recent research in the area of cellulose nanomaterial production from different sources. Due to their abundance, renewability, high strength and stiffness, eco-friendliness and low weight, numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high-performance applications. This report covers an introduction to the definition of nanocellulose as well as the methods used for isolation of nanomaterials (including nanocrystals and nanofibers, CNCs and CNFs, respectively) from various sources. The web-like network structure (CNFs) can be extracted from natural sources using mechanical processes, which include high-pressure homogenization, grinding and refining treatments. Also, rod-like CNCs can be isolated from sources such as wood, plant fibers, agricultural and industrial bioresidues, tunicates and bacterial cellulose using an acid hydrolysis process. Following this, the article focuses on the characterization methods, material properties and structures. Encyclopedic characteristics of CNFs and CNCs obtained from different source materials and/or studies are also included. The current report is a comprehensive review of the literature regarding nanocellulose isolation and demonstrates the potential of cellulose nanomaterials for a wide range of high-tech applications.

Different preparation methods and properties of nanostructured cellulose from various natural resources and residues: a review

In this review we introduce recent advances in the development of cellulose nanomaterials and the construction of high order structures by applying some principles of colloid and interface science. These efforts take advantage of natural assemblies in the form of fibers that nature constructs by a biogenetic bottom-up process that results in hierarchical systems encompassing a wide range of characteristic sizes. Following the reverse process, a top-down deconstruction, cellulose materials can be cleaved from fiber cell walls. The resulting nanocelluloses, mainly cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC, i.e., defect-free, rod-like crystalline residues after acid hydrolysis of fibers), have been the subject of recent interest. This originates from the appealing intrinsic properties of nanocelluloses: nanoscale dimensions, high surface area, morphology, low density, chirality and thermo-mechanical performance. Directing their assembly into multiphase structures is a quest that can yield useful outcomes in many revolutionary applications. As such, we discuss the use of non-specific forces to create thin films of nanocellulose at the air–solid interface for applications in nano-coatings, sensors, etc. Assemblies at the liquid–liquid and air–liquid interfaces will be highlighted as means to produce Pickering emulsions, foams and aerogels. Finally, the prospects of a wide range of hybrid materials and other systems that can be manufactured via self and directed assembly will be introduced in light of the unique properties of nanocelluloses.

Nanocellulose properties and applications in colloids and interfaces

We demonstrate all-solid-state flexible supercapacitors with high physical flexibility, desirable electrochemical properties, and excellent mechanical integrity, which were realized by rationally exploiting unique properties of bacterial nanocellulose, carbon nanotubes, and ionic liquid based polymer gel electrolytes. This deliberate choice and design of main components led to excellent supercapacitor performance such as high tolerance against bending cycles and high capacitance retention over charge/discharge cycles. More specifically, the performance of our supercapacitors was highly retained through 200 bending cycles to a radius of 3 mm. In addition, the supercapacitors showed excellent cyclability with Csp (∼20 mF/cm2) reduction of only <0.5% over 5000 charge/discharge cycles at the current density of 10 A/g. Our demonstration could be an important basis for material design and development of flexible supercapacitors.

All-Solid-State Flexible Supercapacitors Fabricated with Bacterial Nanocellulose Papers, Carbon Nanotubes, and Triblock-Copolymer Ion Gels

Nanocellulose was prepared by acid hydrolysis of microcrystalline cellulose (MCC) at different hydrobromic acid (HBr) concentrations. Polyvinyl alcohol (PVA) composite films were prepared by the reinforcement of nanocellulose into a PVA matrix at different filler loading levels and subsequent film casting. Chemical characterization of nanocelluloses was performed for the analysis of crystallinity (Xc), degree of polymerization (DP), and molecular weight (Mw). The mechanical and thermal properties of the nanocellulose reinforced PVA films were also measured for tensile strength and thermogravimetric analysis (TGA). The acid hydrolysis decreased steadily the DP and Mw of MCC. The crystallinity of MCC with 1.5 M and 2.5 M HBr showed a significant increase due to the degradation of amorphous domains in cellulose. Higher crystalline cellulose showed the higher thermal stability than MCC. From X-ray diffraction (XRD) analysis, nanocellulose samples showed the higher peak intensity than MCC cases. Reduction of MCC particle by acid hydrolysis was clearly observed from scanning electron microscope (SEM) images. The tensile and thermal properties of PVA composite films were significantly improved with the increase of the nanocellulose loading.

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The optimal fertilization practice is that which maximizes seedling growth and minimizes nutrient loss. We tested three fertilization strategies: (1) constant fertilization (2) a three-stage rate, and (3) exponential fertilization on Liriodendron tulipifera and Larix leptolepis containerized seedlings. Growth performance, nutrient uptake, and nutrient loss in leaching were measured. Height, root collar diameter, and dry weight of both species were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three-stage treatments. Generally, nutrient losses in leached solutions were higher in constant and three-stage than the exponential treatment. Nutrient use efficiency was calculated as the ratio of the nutrient content of the seedlings to the amount of nutrient applied to the containers. The nitrogen use efficiency in the constant, three-stage, and exponential treatments was 63, 61, and 85% for yellow poplar, respectively, and 35, 30, and 53% for larch. Similar results were obtained for phosphorus and potassium. Thus, the exponential treatment had the highest nutrient use efficiency as well as the least nutrient loss. Adjusting fertilization rates can reduce soil and water contamination around the nursery without compromising growth performance, which reduces both producer’s investments and environmental impacts.

Minimizing nutrient leaching and improving nutrient use efficiency of Liriodendron tulipifera and Larix leptolepis in a container nursery system

Sleep plays an important role in restoring unbalanced physical, psychological, and physiological functions by providing rest and stability. It also maintains homeostasis and affects individual well-being and quality of life. The purpose of this study was to investigate the effects of sleep quality on sensory processing characteristics of sensory processing characteristics and sleep quality of 208 healthy adults. The results showed that subjective sleep quality, sleep disturbance, and daytime dysfunction were significantly correlated with all sensory processing domains, and low sensory registration, sensory pursuit, sensory sensitivity, and sensory avoidance And there was a significant correlation with the characteristics. The results of this study suggest that sleep disturbance, sleep disturbance, and daytime dysfunction are correlated with sensory processing and may affect the daily life of adults. Therefore, we propose a comprehensive intervention to Received(May 2, 2019), Review Result(May 16, 2019) Accepted(June 13, 2019), Published(June 30, 2019) Associate Professor, 54538, Dept. of Occupational Therapy, Wonkwang Univ. / Institution of Health Improvement, Wonkwang Univ. Iksan, Korea E-mail: tiffaniey@wku.ac.kr (Corresponding Author) Associate Professor, 54538, Dept. of Occupational Therapy, Wonkwang Univ. / Institution of Health Improvement, Wonkwang Univ. Iksan, Korea E-mail: otprime@wku.ac.kr Relationship Between Sensory Processing and Quality of Sleep in Adults Copyright c 2019 HSST 572 confirm the characteristics of sleep during intervention for occupational therapy for sensory processing dysfunction.

Effects of Fertilization Methods on the Growth and Physiological Characteristics of Larix kaempferi Seedlings in the Container Nursery System

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate growth performance, photosynthesis, chlorophyll fluorescence, and chlorophyll contents of Liriodendron tulipifera growing under three different fertilization treatments (Constant rate, Three-stage rate, and Exponential rate fertilization). Root collar diameter, height, and biomass of L. tulipifera were the highest at Constant treatment. Like growth performance, seedling quality index (SQI) were higher at Constant than at other treatments, but not significantly different among treatments. L. tulipifera showed good photosynthetic capacity at all treatments. Photochemical efficiency and chlorophyll contents were significantly lower at Exponential than at other treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

The Effects of Fertilization on Growth Performances and Physiological Characteristics of Liriodendron tulipifera in a Container Nursery System


 
 Persimmon peels are mostly discared as a by-product of dried persimmon
 manufacturing, but effective use is required as it contains various functional
 constituents. This study covers the preparation of carotenoid-enriched oil by
 ultrasound treatment of persimmon peel in soybean oil solvent, and the
 investigation of its physicochemical characteristics. Using the Box-Behnken
 design and response surface methodology, the optimal extraction conditions
 (temperature, 62°C; time, 32 min; and persimmon peel to oil ratio, 1:3.1)
 were determined based on the carotenoid concentration of the extract. The
 physicochemical characteristics of the extract obtained under optimal conditions
 and the untreated soybean oil (control) were compared. The total carotenoid
 content of the extract increased. The carotenoid-enriched soybean oils had a
 lighter color than the controls, but with high redness and yellowness values.
 The effect of sonication and a component of the persimmon peel on the oxidation
 and heating stability of soybean oil was weak. The viscosity and activation
 energy of carotenoid-enriched soybean oil were slightly higher than those of the
 control. Thus, it was possible to prepare yellow-red carotenoid-enriched soybean
 oil by applying ultrasonic-soybean oil solvent extraction to persimmon peel. The
 oil is expected to be useful as an additive as well as a substitute for general
 edible oils.


Physicochemical characteristics of carotenoid-enriched extract
 prepared from persimmon peels by ultrasound-assisted extraction with soybean
 oil solvent

Soo won Lee

Papers

Nanocellulose reinforced PVA composite films: Effects of acid treatment and filler loading

Minimizing nutrient leaching and improving nutrient use efficiency of Liriodendron tulipifera and Larix leptolepis in a container nursery system

Effects of Fertilization Methods on the Growth and Physiological Characteristics of Larix kaempferi Seedlings in the Container Nursery System

The Effects of Fertilization on Growth Performances and Physiological Characteristics of Liriodendron tulipifera in a Container Nursery System

Physicochemical characteristics of carotenoid-enriched extract prepared from persimmon peels by ultrasound-assisted extraction with soybean oil solvent