The chemo-enzymatic modification and degumming of hemp fiber by the laccase-2,2,6,6-tetramethylpiperidine-1-oxyl radical-hemicellulase system and physico-chemical properties of the products

2018 ◽  
Vol 89 (12) ◽  
pp. 2433-2443 ◽  
Author(s):  
Xiang Yeping ◽  
Yu Jianyong ◽  
Liu Liu ◽  
Zhang Ruiyun ◽  
Qu Yongshuai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Moisture Sorption ◽  
Strong Acid ◽  
Acetate Buffer Solution ◽  
Enzymatic Modification ◽  
Buffer Solution ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Physico Chemical ◽  
Physical And Chemical

In this study, we found an environmentally friendly system in the degumming of hemp fiber without using a strong acid and alkali. The chemo-enzymatic modification and degumming of hemp fiber used an acetic acid–sodium acetate buffer solution containing laccase, hemicellulase and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) under a mild condition (pH = 5, T = 50℃). Through comparing and analyzing the physical and chemical properties of fiber products under different treatments, we found the method involving treatment with TEMPO/laccase/hemicellulase not only greatly removed most of the gum attached on the surface of the raw hemp fiber, but also introduced surface-active aldehyde and carboxyl groups into the fiber. The performances of the hemp fibers with different treatments were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. We also found the product was finer, with a lower content of non-cellulosic components and it had better water uptake properties (moisture sorption and water retention value), which has potential application values in textile industries.

scholarly journals The Physical and Chemical Properties of Hemp Fiber Prepared by Alkaline Pectinase-Xylanase System

2021 ◽  
Author(s):  
Shuyuan Zhao ◽  
Zhihui Qin ◽  
Ruiyun Zhang ◽  
Naiqiang Li ◽  
Liu Liu ◽  
...  
Keyword(s):  
Textile Industry ◽  
Chemical Properties ◽  
Moisture Sorption ◽  
Xrd Analysis ◽  
Retention Performance ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Removal Ratio ◽  
Degumming Process ◽  
Physical And Chemical

Abstract Degumming is the vital and critical step in the preparation of hemp fiber for textile application. However, the traditional chemical degumming processes use large amounts of harmful chemicals, especially strong alkalis, which have caused severe challenges to the environment. The reaction conditions of alkaline pectinase and alkaline pectinase were studied in this research, and the alkaline pectinase-xylanase system was successfully applied to the degumming of hemp fibers at mild conditions (T=55 ℃ and pH=8.0) without strong alkali. A comparative analysis of hemp fibers treated under different conditions showed that the gum removal ratio could reach about 50% within 5.5 h of alkaline pectin-xylanase system degumming, making fiber smoother and stronger. After alkaline pectin-xylanase system treatment (0.6 g pectinase, 0.3 g xylanase, 55 ℃, pH 8.0, 5.5 h), the removal ratio of pectin and hemicellulose reached 75 % and 40 %, respectively. And linear density and tenacity of the fiber was 17.4 dtex and 5.62 cN/dtex, respectively. SEM, FT-IR and XRD analysis furthermore demonstrated the excellent effects of the proposed process. The degumming fiber had better water retention performance (513 %) and moisture sorption (8.9 %), which has more excellent application prospects in the textile industry. Moreover, the method abandons the use of acid and alkali and can provide an eco-friendly degumming process for hemp fiber.

Circulating solution for the degumming and modification of hemp fiber by the laccase–2,2,6,6-tetramethylpiperidine-1-oxyl radical–hemicellulase system

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4339-4348 ◽  
Author(s):  
Xiang Yeping ◽  
Liu Liu ◽  
Zhang Ruiyun ◽  
Yu Jianyong ◽  
Fang Bin ◽  
...  
Keyword(s):  
Textile Industry ◽  
Water Retention ◽  
Moisture Absorption ◽  
Acetate Buffer Solution ◽  
Water Retention Value ◽  
Buffer Solution ◽  
Hemp Fiber ◽  
Residual Rate ◽  
Hemp Fibers ◽  
One Step

Hemp fiber, as a kind of renewable textile fiber, has evoked much interest due to its excellent properties in various fields. It has been investigated in just one step to finish the process of chemo-enzymatic degumming and modification of hemp fiber, which is done in acetic acidsodium acetate buffer solution containing laccase (6.0 g), hemicellulase (0.3 g) and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (0.3 g) under a mild condition (pH 5, 50C). The degumming effects of different batches of raw hemp fibers were also discussed. We found that the residual rate, fineness, length and tensile strength of degummed fiber were 15–27%, 9.00–24.00 dtex, 14.00–19.00 cm and 3.8–5.1 cN/dtex, respectively. Meanwhile, some of the oxidized functional groups were introduced into degummed fiber, which improved the moisture absorption and water retention value of the hemp fiber. The hemp fiber treated by this process could be further improved and then applied in the textile industry.

Ionic Liquids in Analytical Chemistry: Applications and Recent Trends

2021 ◽  
Vol 17 ◽  
Author(s):  
Giuseppe Maria Merone ◽  
Angela Tartaglia ◽  
Enrica Rosato ◽  
Cristian D’Ovidio ◽  
Abuzar Kabir ◽  
...  
Keyword(s):  
Analytical Chemistry ◽  
Ionic Liquids ◽  
Stationary Phases ◽  
Extraction Procedure ◽  
Chemical Properties ◽  
Electrochemical Analysis ◽  
Physico Chemical ◽  
Recent Trends ◽  
Number Of Publications ◽  
Physical And Chemical

Background: Ionic liquids (ILs) are a unique class of compounds consisting exclusively of cations and anions that possess distinctive properties such as low volatility, high thermal stability, miscibility with water and organic solvents, electrolytic conductivity and non-flammability. Ionic liquids have been defined as "design solvents", because it is possible to modify their physical and chemical properties by appropriately choosing cations and anions, in order to meet the specific characteristics based on their potential application. Introduction: Due of their tunable nature and properties, ILs are considered as the perfect candidates for numerous applications in analytical chemistry including sample preparation, stationary phases in liquid or gas chromatography, additives in capillary electrophoresis, or in mass spectrometry for spectral and electrochemical analysis. In the last years, the number of publications regarding ILs has rapidly increased, highlighting the broad applications of these compounds in various fields of analytical chemistry. Results: This review first described the main physico-chemical characteristics of ionic liquids, and subsequently reported the various applications in different subdisciplines of analytical chemistry, including the extraction procedure and separation techniques. Furthermore, in each paragraph the most recent applications of ionic liquids in the food, environmental, biological, etc. fields have been described. Conclusion: Overall, the topic discussed highlights the key role of ionic liquids in analytical chemistry, giving hints for their future applications in chemistry but also in biology and medicine.

scholarly journals Effect of Slice Weight and Soaking Time on the Physico-Chemical Properties of Cassava Flour (Manihotesculentus) used for Bakery Products

2021 ◽  
pp. 10-24
Author(s):  
C. R. Abah ◽  
C. N. Ishiwu ◽  
J. E. Obiegbuna ◽  
E. F. Okpalanma ◽  
C. S. Anarado
Keyword(s):  
Chemical Properties ◽  
Process Variables ◽  
Soaking Time ◽  
Cassava Flour ◽  
Baked Goods ◽  
Cassava Root ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
And Chemical Properties

Quality cassava(Manihotesculentus, Crantz) flour is often influenced by process variables such as slice weight and soaking time which may affect its nutritional quality. In this study, the effect of process variables (slice weight and soaking time) on quality of cassava flour was carried out. Cassava root was peeled, washed and cut into varied sizes (25.86 - 54.14 g) and soaked at varied time (7.03 - 40.97 h). The proximate composition, physical and chemical properties of the flour were carried out using standard methods. The result in our findings showed that slice weight and soaking time had significant increase (p<0.05) on the proximate and physico-chemical properties of the flour.The amylose and amylopectin content of the flour increased with increasing soaking time while the hydrogen cyanide content decreased with increase in soaking time. Overall, the quality cassava flour displayed desirable properties for its incorporation into baked goods.

scholarly journals Free-standing spider silk webs of the thomisid Saccodomus formivorus are made of composites comprising micro- and submicron fibers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Christian Haynl ◽  
Jitraporn Vongsvivut ◽  
Kai R. H. Mayer ◽  
Hendrik Bargel ◽  
Vanessa J. Neubauer ◽  
...  
Keyword(s):  
Spider Silk ◽  
Structural Integrity ◽  
Chemical Properties ◽  
Free Standing ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Crab Spiders ◽  
Ambush Predators ◽  
The Web ◽  
And Chemical Properties

Abstract Our understanding of the extraordinary mechanical and physico-chemical properties of spider silk is largely confined to the fibers produced by orb-weaving spiders, despite the diversity of foraging webs that occur across numerous spider families. Crab spiders (Thomisidae) are described as ambush predators that do not build webs, but nevertheless use silk for draglines, egg cases and assembling leaf-nests. A little-known exception is the Australian thomisid Saccodomus formivorus, which constructs a basket-like silk web of extraordinary dimensional stability and structural integrity that facilitates the capture of its ant prey. We examined the physical and chemical properties of this unusual web and revealed that the web threads comprise microfibers that are embedded within a biopolymeric matrix containing additionally longitudinally-oriented submicron fibers. We showed that the micro- and submicron fibers differ in their chemical composition and that the web threads show a remarkable lateral resilience compared with that of the major ampullate silk of a well-investigated orb weaver. Our novel analyses of these unusual web and silk characteristics highlight how investigations of non-model species can broaden our understanding of silks and the evolution of foraging webs.

PHYSICO-CHEMICAL PROPERTIES OF A NEW CLAY-BASED SORBENT

2019 ◽  
Vol 9 (1) ◽  
pp. 52-56
Author(s):  
Sergey V. STEPANOV ◽  
Olga N. PANFILOVA ◽  
Kristina K. ADDUGAFFAROVA
Keyword(s):  
Ion Exchange ◽  
Chemical Properties ◽  
Thermal Method ◽  
Chemical Parameters ◽  
Aluminum Oxides ◽  
Ir Spectrometry ◽  
Physico Chemical ◽  
Preliminary Preparation ◽  
Physical And Chemical ◽  
Finished Sample

The main physical and chemical parameters of a new sorbent developed on the basis of the minerals of the Samara region: clays, peat and dolomite are considered. The particle size of the clay after grinding at the stage of preliminary preparation was less than 1 nm, which relates them to highly dispersed materials. A chemical analysis of the composition of the components showed a high content of silicon and aluminum oxides, which possess ion exchange properties, and also made it possible to assign clays to montmorillonite rocks. The modification of the sorbent was carried out by thermal method. The density of the finished sample was 1.8 g / cm3. The method of scanning electron microscopy showed that the structure of the finished sample belongs to spongy bodies. The method of IR spectrometry confirmed the presence of functional groups in the crystal lattice of the sorbent, which cause not only the physical, but also the ion exchange and chemical nature of sorption.

Some physical and chemical properties of the lettuce seed endosperm

1976 ◽  
Vol 54 (13) ◽  
pp. 1512-1522 ◽  
Author(s):  
Henry L. Speer ◽  
A. I. Hsiao
Keyword(s):  
Fluid Layer ◽  
Chemical Properties ◽  
Strong Acid ◽  
Cellulose Membrane ◽  
Lettuce Seed ◽  
Temperature Dependent ◽  
Strong Base ◽  
Lettuce Seeds ◽  
Physical And Chemical ◽  
Osmotic Activity

Lettuce seeds (Lactuca sativa) are shown to be encased in an osmotically active cellulose membrane derived from the endosperm. The osmotic activity of this membrane is maintained in seeds treated with strong acid (4 M HCl), strong base (4.4 M NaOH), organic solvents, and protein solvents, indicating that there is no contribution of lipid, protein, or living cells to the osmotic properties of the membrane. Only cellulose solvents such as xanthate and cellulase were effective in disrupting the membrane.When dry seeds are treated with 50% solutions of methanol, ethanol, or acetone or with 10 mM HgCl2, they become osmotically distended seeds (ods) as a result of the accumulation of soluble molecules in the fluid layer (EEF) between the membrane and embryo. This process is temperature dependent and appears to require enzymatic activity.The molecular exclusion limit of the ods membrane was measured by osmotic equilibration techniques and was found to be about 300 daltons. This then explains previous observations on the impermeability of lettuce seeds to substances such as actinomycin D (mol. wt. 1255.5) during germination. Molecules of molecular weight greater than about 300 daltons will be excluded until the endospermal barrier is ruptured at about 10–12 h after germination onset.

Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process

2015 ◽  
Vol 1107 ◽  
pp. 267-271
Author(s):  
Sodipo Bashiru Kayode ◽  
Azlan Abdul Aziz
Keyword(s):  
Silica Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Colloidal Suspension ◽  
Sol Gel ◽  
Chemical Properties ◽  
Colloidal Suspensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Physico Chemical ◽  
Physical And Chemical

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.

Preparation of Sulfated Zirconia Using Modified Sol Gel Method

2014 ◽  
Vol 896 ◽  
pp. 153-158
Author(s):  
Anis Kristiani ◽  
Kiky C. Sembiring ◽  
Fauzan Aulia ◽  
Joddy Arya Laksmono ◽  
Silvester Tursiloadi ◽  
...  
Keyword(s):  
Sulfated Zirconia ◽  
Sol Gel ◽  
Chemical Properties ◽  
Gel Method ◽  
Sol Gel Method ◽  
Organic Bases ◽  
Physico Chemical ◽  
Medium Porosity ◽  
Cetyltrimethyl Ammonium ◽  
Physical And Chemical

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.

scholarly journals Physical and Chemical Properties and Methods of Control of Pantoprazol Sodium Sesquihydrate (Review)

2020 ◽  
Vol 9 (1) ◽  
pp. 46-53
Author(s):  
V. A. Shelekhova ◽  
K. R. Savelyeva ◽  
S. V. Polyakov ◽  
V. N. Shestakov
Keyword(s):  
Chemical Properties ◽  
Reaction Products ◽  
Chemical Methods ◽  
Spectrophotometric Methods ◽  
Physico Chemical ◽  
Inflammatory Drugs ◽  
Physical And Chemical ◽  
Direct Spectrophotometry ◽  
Methods Of Control ◽  
And Chemical Properties

Introduction. Pantoprazole sodium sesquihydrate is a proton pump inhibitor. This substance is used in the treatment of peptic ulcer of the duodenum or stomach in the acute phase, including those associated with the use of non-steroidal anti-inflammatory drugs.Text. Pantoprazole is sodium 5-(difluoromethoxy)-2-[(RS)-[(3,4-dimethoxypyridin-2-yl)methyl]sulfinyl]benzimidazol-1-ide sesquihydrate in its structure. The substance is readily soluble in water and ethyl alcohol. The identification of pantoprazole is confirmed by infrared absorption spectrophotometry, as well as by a positive reaction to sodium ion. For the assay of this substance chemical and physico-chemical methods are used. The first group of methods includes titration in a non-aqueous medium with perchloric acid and permanganatometry. Physico-chemical methods used for pantoprazole assay are spectrophotometry and HPLC. The most commonly used method is direct spectrophotometry associated with the measurement of optical density at a wavelength of the maximum absorption of pantoprazole in various solvents. In addition, spectrophotometric methods of assay are known, based on the study of the absorption of colored pantoprazode reaction products. The derivative spectrophotometry is used for the analysis of its preparations. The control of the content of impurities and pantoprazole in the substance and its dosage forms is carried out, as a rule, using HPLC.Conclusion. An analysis of the literature has shown that this substance is unstable. Therefore, this feature of pantoprazole must be considered when choosing excipients when developing a dosage form. The preferred method for analyzing pantoprazole preparations is HPLC, since it is possible to determine the substance in the presence of other compounds, which will allow one to control the quantitative content and stability of pantoprazole in the preparation.

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