scholarly journals Effect of sodium hypochlorite concentration during pre-treatment on isolation of nanocrystalline cellulose from Leucaena leucocephala (Lam.) mature pods

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3137-3158
Author(s):  
Aida Safina Aridi ◽  
Nyuk Ling Chin ◽  
Nur Akmal Ishak ◽  
Nor Nadiah Mohamad Yusof ◽  
Kazunori Kadota ◽  
...  

Mature pods of Leucaena leucocephala (Lam.) de Wit were utilized as raw material for nanocrystalline cellulose (NCC) production. NCC’s isolation begins with L. leucocephala fiber’s alkaline treatment with sodium hydroxide, followed by bleaching treatment at three different percentages (3%, 5%, and 7%) of sodium hypochlorite. Acid hydrolysis was then conducted to obtain NCC, which was comprehensively characterized in terms of morphology, chemical functional groups, whiteness index, and crystallinity. Fourier-transform infrared spectroscopy (FTIR) and chemical composition results showed that alkali treatment (NaOH) and bleaching (3%, 5%, and 7% of sodium hypochlorite, NaClO) were effective in the removal of lignin and hemicellulose. The variation of sodium hypochlorite concentration affected physical and structural characteristics of the NCC produced, which exhibited a rod-shaped structure with diameters ranging from 17 to 49 nm. These observations provide insight into the potential utilization of L. leucocephala as raw material for preparing nanocellulose, which may address problems of the underutilized mature pods.

Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова ◽  
Д.Д. Манойлович

Получение доступных сорбентов на основе природных материалов, для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах является актуальным направлением исследований. Сорбенты на основе технической целлюлозы удовлетворяют этим требованиям. В работе для получения технической целлюлозы предложено использовать биомассу соломы риса. Для удаления из соломы риса минерального компонента при проведении окислительно-органосольвентной варки используют стадию щелочной обработки, которая приводит к деструкции полисахаридов, снижая выход технической целлюлозы. В связи с этим целью работы является изучение закономерностей проведения щелочной обработки соломы риса для максимального сохранения высокого выхода технической целлюлозы, извлечения минеральной части и возможности применения данной целлюлозы в качестве колористического сорбента. С учетом предварительных исследований найдены оптимальные значения технологических факторов, обеспечивающих высокий выход волокнистого материала из соломы риса при минимальном содержании в нем минеральных компонентов. Последующая органосольвентная варка позволяет получить техническую целлюлозу с выходом – 48,8% от абсолютно сухого сырья (а.с.с), зольностью 0,05% от а.с.с., содержанием лигнина 2,5% от а.с.с., удовлетворительными прочностными характеристиками, высокими сорбционными свойствами, необходимой белизной и рН водной вытяжки. Выявлено, что техническая целлюлоза из соломы риса содержит металлы, накопленные биомассой за вегетативный период. Щелочная обработка и окислительно-органосольвентная делигнификация в большинстве случаев приводят к снижению концентрации металлов в технической целлюлозе. Исключение составляют алюминий, железо и свинец, содержание которых в технической целлюлозе увеличивается. Таким образом, целлюлоза, полученная в оптимальных условиях щелочной обработки и последующей окислительно-органосольвентной варки из соломы риса, с учетом содержащихся в ней металлов, пригодна для использования в качестве сорбента для визуального колористического определения содержания ионов металлов в загрязненных природных и сточных водах. Receive available sorbents based on natural materials for visual color determination of the content of metal ions in contaminated natural and waste waters is a topical area of research. Sorbents on the basis of technical cellulose satisfy these requirements. In the process of obtaining technical cellulose is proposed to use biomass straw rice. Removal of straw rice mineral component when carrying out the oxidation-organosolvent use the cooking stage alkali treatment, which leads to degradation of polysaccharides, reducing the output of technical cellulose. In this regard, the aim of this work is to study the regularities of the alkaline treatment of rice straw for maximum preservation of the high output technical cellulose, extracting the mineral and the possibility of using the cellulose as the colour of the sorbent. Taking into account the preliminary studies, optimal conditions of technological factors were found ensuring a high yield of fibrous material from rice straw with a minimum content of mineral components in it. Subsequent organosolvent pulping yields technical pulp with a yield of 48.8% bone dry raw material (BDRM), an mineral ash content of 0.05% of BDRM, a lignin content of 2.5% of BDRM, satisfactory strength properties, high sorption properties, the necessary whiteness and pH of aqueous extract. It is revealed that the technical cellulose from straw of rice contains metals accumulated biomass during the vegetation period. Alkaline treatment and oxidative-organosolvent the delignification in most cases leads to a decrease of metal concentrations in pulp technical. With the exception of aluminum, iron and lead, the content of which is technical cellulose increases. Thus, cellulose obtained in optimum conditions of alkaline treatment and subsequent oxidation-organosolvent pulping of straw of rice, taking into account the contained metals suitable for use as a sorbent for visual color determination of the content of metal ions in polluted natural and sewage waters.


2019 ◽  
Vol 7 (4.14) ◽  
pp. 369
Author(s):  
S N Surip ◽  
F M A Aziz ◽  
A H Yuwono ◽  
N Sofyan

In the past decades, conventional petroleum-based plastics have resulted in environmental and sustainability issues. Thus, there has been significant interest in the utilization of natural materials for nanofibers product such as for filtration media.  However, poor compatibility exists between polymers and natural fibers due to natural fibers hydrophilic properties leading to poor nanofibers formation. In this study, Pineapple Leaf Fiber (PALF) remarkable properties were explored. PALF undergo alkaline treatment and bleaching treatment in order to improve its compatibility. Thermal, morphology and structural properties of PALF raw (PR), PALF after alkali treatments (PA) and PALF after alkali + bleaching treatment (PB) were studied. Further, all the samples were diluted using Trifluoroacetic Acid (TFA) as the solvent and Polyethylene Terephthalate (PET) as the polymer carrier and proceed to electrospinning to produce a nanofibers electrospun mats. The electrospun mats were then characterized in terms of its chemical properties using Fourier transform infrared spectroscopy (FTIR) as well as the morphology which using Fields Emission Scanning Electron Microscopy (FESEM).  FTIR result shows the electrospun PET does not produce any peak at ~3400cm-1 due to its hydrophobic properties. Nevertheless, with addition of PALF, the peak was significantly increased. FESEM results indicated that the present of fibers led to a tendency of lower average fiber diameter compared to the neat PET. Unconnected and thin fibers were coexited from single fiber of PALF raw electrospun indicated that new fibers were ejected however the bond were collapsed during ejection thus did not produce a complete single fiber. Despite that, more uniform fibers of electrospun mat were produced by pre-treatment of PALF. 


2014 ◽  
Vol 895 ◽  
pp. 174-177
Author(s):  
Noriean Azraaie ◽  
Nurul Aimi Mohd Zainul Abidin ◽  
Nur Ain Ibrahim ◽  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
...  

Alkali treatment and bleaching have been applied on banana fibers obtained from harvested pseudo-stem of the banana plant Musa acuminata collected in Banting, Selangor, Malaysia. The structure and morphology of the fibers have been found to be affected by the used of alkaline treatment and bleaching. The crystallite size and percentage crystallinity of the untreated (raw banana fibers) and treated (microfibrils cellulose) fibers were investigated using X-Ray Diffraction (XRD). XRD studies shows that the treated cellulose prepared by such chemical treatment (alkali and bleaching treatment) were more crystalline than the untreated banana fibers.


2016 ◽  
Vol 27 (5) ◽  
pp. 598-605
Author(s):  
S. Sivarathnakumar ◽  
G. Baskar ◽  
R. Praveen Kumar ◽  
B. Bharathiraja

Purpose –Prosopis juliflora is a raw material for long-term sustainable production of bioethanol. The purpose of this paper is to identify the best combination of pre-treatment strategy implemented on the lignocellulosic biomass Prosopis juliflora for bioethanol production. Design/methodology/approach – Pre-treatment of lignocellulosic material was carried out using acid, alkali and sonication in order to characterize the biomass for bioethanol production. Prosopis juliflora stem was subjected to steam at reduce temperature (121°C) for one hour residence time initially. Further acid and alkali treatment was carried out individually followed by combinations of acid and sonication, alkali and sonication. Sodium hydroxide, potassium hydroxide, hydrochloric acid, sulphuric acid and nitric acid were used with 3 per cent (w/v) and 3 per cent (v/v) concentration under temperature range of 60-90°C for 60 min incubation time. Sonication under 60°C for 5 min and 40 KHz frequency was carried out. Pre-treated sample were further characterised using field emission scanning electron microscope and Fourier transform infrared spectroscopy to understand the changes in surface morphology and functional characteristics. Findings – In sono assisted acid treatment-based method, nitric acid yields better cellulose content at 70°C and removes lignin that even at increased temperatures no burning was observed. Originality/value – The paper adds to the scarce research available on the combination of auto hydrolysis coupled with sono assisted acid/alkali hydrolysis which is yet to be practiced.


2008 ◽  
Vol 57 (3) ◽  
pp. 423-429 ◽  
Author(s):  
M. Drouin ◽  
C. K. Lai ◽  
R. D. Tyagi ◽  
R. Y. Surampalli

Wastewater sludge is a complex raw material that can support growth and protease production by Bacillus licheniformis. In this study, sludge was treated by different thermo-alkaline pre-treatment methods and subjected to Bacillus licheniformis fermentation in bench scale fermentors under controlled conditions. Thermo-alkaline treatment was found to be an effective pre-treatment process in order to enhance the proteolytic activity. Among the different pre-treated sludges tested, a mixture of raw and hydrolysed sludge caused an increase of 15% in the protease activity, as compared to the untreated sludge. The benefit of hydrolysis has been attributed to a better oxygen transfer due to decrease in media viscosity and to an increase in nutrient availability. Foam formation was a major concern during fermentation with hydrolysed sludge. The studies showed that addition of a chemical anti-foaming agent (polypropylene glycol) during fermentation to control foam could negatively influence the protease production by increasing the viscosity of sludge.


Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 404
Author(s):  
Alexandru Amărioarei ◽  
Frankie Spencer ◽  
Gefry Barad ◽  
Ana-Maria Gheorghe ◽  
Corina Iţcuş ◽  
...  

Current advances in computational modelling and simulation have led to the inclusion of computer scientists as partners in the process of engineering of new nanomaterials and nanodevices. This trend is now, more than ever, visible in the field of deoxyribonucleic acid (DNA)-based nanotechnology, as DNA’s intrinsic principle of self-assembly has been proven to be highly algorithmic and programmable. As a raw material, DNA is a rather unremarkable fabric. However, as a way to achieve patterns, dynamic behavior, or nano-shape reconstruction, DNA has been proven to be one of the most functional nanomaterials. It would thus be of great potential to pair up DNA’s highly functional assembly characteristics with the mechanic properties of other well-known bio-nanomaterials, such as graphene, cellulos, or fibroin. In the current study, we perform projections regarding the structural properties of a fibril mesh (or filter) for which assembly would be guided by the controlled aggregation of DNA scaffold subunits. The formation of such a 2D fibril mesh structure is ensured by the mechanistic assembly properties borrowed from the DNA assembly apparatus. For generating inexpensive pre-experimental assessments regarding the efficiency of various assembly strategies, we introduced in this study a computational model for the simulation of fibril mesh assembly dynamical systems. Our approach was based on providing solutions towards two main circumstances. First, we created a functional computational model that is restrictive enough to be able to numerically simulate the controlled aggregation of up to 1000s of elementary fibril elements yet rich enough to provide actionable insides on the structural characteristics for the generated assembly. Second, we used the provided numerical model in order to generate projections regarding effective ways of manipulating one of the the key structural properties of such generated filters, namely the average size of the openings (gaps) within these meshes, also known as the filter’s aperture. This work is a continuation of Amarioarei et al., 2018, where a preliminary version of this research was discussed.


2012 ◽  
Vol 620 ◽  
pp. 314-319
Author(s):  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
Saadah Abdul Rahman

Hardwood is wood from angiosperm trees. The characteristic of hardwood include flowers, endosperm within seeds and the production of fruits that contain the seeds. This paper aims to discuss the preparation and characterization of cellulose obtained from hardwood. The hardwood Merbau (Intsia bijuga) was chosen as raw material in this study. Alkaline treatment and delignification methods were used for the preparation of cellulose. Acid hydrolysis was employed to produce cellulose nanocrystal (CNC). The treated and untreated samples were characterized using x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The final product, from both trated and untreated samples were then compared.


2013 ◽  
Vol 559 ◽  
pp. 13-18 ◽  
Author(s):  
Anna Borisova ◽  
Skaidrīte Reihmane

Successful results of textile materials finishing process in order to gain desired properties to the fabric according to customers’ demands mainly depend on properly-carried pre-treatment stages. The present study covers twill weave cotton/polyester fabric’s modification in alkaline medium at different temperatures and treatment durations through exhaustion (hot and cold treatment) and pad-steam process. An influence of the reduction agent addition was ascertained. Weight loss, water absorbency, vertical wicking, dye uptake, colour measurements, surface morphology and psysicomechanical characteristics were determined. Samples and recommendations of optimal alkaline treatment technologies are developed.


2014 ◽  
Vol 915-916 ◽  
pp. 871-874 ◽  
Author(s):  
Xian Ping Zeng ◽  
Jin Fa Liu

In this paper, the hemp / cotton / polyester mesh knitted fabric (Han / C / T) is treated by alkali treatment, conventional dyeing and alkali pre-treatment dyeing. We have obtained the conclusion that alkali treatment improves the dyeing effect. Alkali pre-treatment dyeing was done after alkali treatment. The fabric dyeing effect is improved obviously. The optimum process come from orthogonal experiment (dyes 2.5% owf, Na2SO4 :30g/L, Na2CO3:10g/L, liquor ratio (1:50) and 90°C×50 min). Through this optimum process, dyeing effect for hemp / cotton / polyester mesh knitted fabric is close to the pure cotton fabric dyeing effect.


Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
María García-Torreiro ◽  
Miguel Álvarez Pallín ◽  
María López-Abelairas ◽  
Thelmo A. Lu-Chau ◽  
Juan M. Lema

AbstractBioconversion of lignocellulosic materials into ethanol requires an intermediate pretreatment step for conditioning biomass. Sugar yields from wheat straw were previously improved by the addition of a mild alkali pretreatment step before bioconversion by the white-rot fungus Irpex lacteus. In this work, an alternative alkaline treatment, which significantly reduces water consumption, was implemented and optimized. Sugar recovery increased 117% with respect to the previously developed alkaline wash process at optimal process conditions (30°C, 30 minutes and 35.7% (w/w) of NaOH). In order to further reduce operational costs, a system for alkali recycling was implemented. This resulted in the treatment of 150% more wheat straw using the same amount of NaOH. Finally, enzymatic hydrolysis was optimized and resulted in a reduction of enzyme dose of 33%.


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