Polylactide latex/nanofibrillated cellulose bionanocomposites of high nanofibrillated cellulose content and nanopaper network structure prepared by a papermaking route

2012 ◽  
Vol 125 (3) ◽  
pp. 2460-2466 ◽  
Author(s):  
Karolina Larsson ◽  
Lars A. Berglund ◽  
Mikael Ankerfors ◽  
Tom Lindström
Keyword(s):  
Network Structure ◽  
Nanofibrillated Cellulose ◽  
Cellulose Content

Nanofibrillated cellulose as nanoreinforcement in Portland cement: Thermal, mechanical and microstructural properties

2016 ◽  
Vol 51 (17) ◽  
pp. 2491-2503 ◽  
Author(s):  
Roukaya Mejdoub ◽  
Halim Hammi ◽  
Joan Josep Suñol ◽  
Mohamed Khitouni ◽  
Adel M‘nif ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Hydration ◽  
Coefficient Of Thermal Expansion ◽  
Nanofibrillated Cellulose ◽  
Partial Replacement ◽  
Cellulose Content ◽  
Cement Pastes ◽  
Eucalyptus Pulp ◽  
Reinforced Cement ◽  
Mechanical And Microstructural Properties

Nanofibrillated cellulose from eucalyptus pulp, produced by high-pressure homogenization, was used as cement partial replacement for cement paste at a content ranging from 0% to 0.5% by weight of cement. The effect of the content of nanofibrillated cellulose on porosity, thermal properties, compressive strength and degree of cement hydration was investigated. Results have shown an improvement in the compressive strength by more than 50% with 0.3 wt% of added nanofibrillated cellulose. The porosity was reduced by nanofibrillated cellulose addition, and the greatest result was achieved with mixture incorporating 0.3 wt% nanofibrillated cellulose. The coefficient of thermal expansion and the thermal conductivity measurements, relative to nanofibrillated cellulose-reinforced cement pastes, have pointed out the reinforcement effectiveness of nanofibrillated cellulose. The degree of cement hydration has increased with nanofibrillated cellulose content. This trend was confirmed by X-ray diffraction and Fourier Transform Infrared spectroscopy. These analyses have revealed that the presence of nanofibrillated cellulose promoted the hydration of cement, by producing more portlandite and calcium silicate gel, which is likely the main reason accounting for the strong enhancement in the compressive strength.

scholarly journals Cellulosic Fiber: Mechanical Fibrillation-Morphology-Rheology Relationships

2021 ◽  
Author(s):  
Tianzhong Yuan ◽  
Jinsong Zeng ◽  
Bin Wang ◽  
Zheng Cheng ◽  
Kefu Chen
Keyword(s):  
Aspect Ratio ◽  
Yield Stress ◽  
Network Structure ◽  
Nanofibrillated Cellulose ◽  
Fiber Suspension ◽  
Elastic Behavior ◽  
Fiber Network ◽  
Cellulosic Fiber ◽  
Mechanical Fibrillation ◽  
The Relationship

Abstract This study aims to investigate the relationship between mechanical fibrillation, morphological properties, and rheological behavior of cellulosic fiber. Three types of cellulosic fibers were obtained by adjusting mechanical fibrillation, namely squashed cellulose, incompletely nanofibrillated cellulose, and completely nanofibrillated cellulose, respectively. The squashed cellulose with large size and small aspect ratio had low entanglement capacity, thus forming a weak fiber network. The corresponding suspension exhibited low viscosity, weak elastic behavior, small yield stress, and low dynamic stability. An obviously increasing aspect ratio and entanglement capacity were observed with increasing mechanical fibrillation, resulting in entangled fiber network structure. Hence, the cellulosic fiber suspension obtained by more mechanical fibrillation exhibited higher viscosity, stronger gel-like behavior, and bigger yield stress. Moreover, the extremely entangled fiber network structure has better anti-deformation capacity and recovery capacity. We revealed the fundamental insights into the relationship between morphologies and rheological properties of cellulosic fiber, paving the way for designing cellulose-based materials.

scholarly journals Modelling and optimization of the last two stages of an environmentally-compatible TCF bleaching sequence

BioResources ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. 6642-6662
Author(s):  
Tamara Llano ◽  
Carlos Arce ◽  
Gema Ruiz ◽  
Naveen Chenna ◽  
Alberto Coz
Keyword(s):  
Linear Optimization ◽  
Cost Savings ◽  
Pulp Mill ◽  
Nanofibrillated Cellulose ◽  
Regenerated Cellulose ◽  
Cellulose Content ◽  
Quality Properties ◽  
Operational Conditions ◽  
Dissolving Pulps ◽  
Two Stages

A totally chlorine free (TCF) bleaching sequence was studied for an acid sulfite pulp mill that produces dissolving pulps. Laboratory analyses of the last two bleaching stages, an oxidant-reinforced alkaline extraction stage (EOP), and a subsequent pressurized peroxide with oxygen stage (PO), were performed on a eucalypt pulp that had been delignified by an ozone (Z) stage in the pulp mill. The goal was to predict the optimal costs and operational conditions for the (EOP)(PO) partial bleach sequence for three different specialty pulp products. Four independent variables affecting the pulp quality properties were examined for each stage (i.e., reaction temperature, reaction time, NaOH dosage and H2O2 dosage). The dependent variables were various pulp properties, such as intrinsic pulp viscosity, alpha-cellulose content, kappa number, and GE brightness. Three scenarios were considered to optimize the bleaching process, which related to a regenerated cellulose product (viscose) that is widely commercialized, and to two novel products (nanocrystalline cellulose (NCC) and nanofibrillated cellulose (NFC). Statistical response surface models indicated that the bleaching behavior of the ozone-treated pulp could be represented by second-order polynomial equations. These non-linear optimization models predict cost savings of 62.2%, 73.4%, and 63.3% for producing viscose, NCC, and NFC pulp grades, respectively.

Design and Preparation of Magnetism-Driven Intelligent Hydrogel Actuators

2021 ◽  
Vol 36 (2) ◽  
pp. 165-171
Author(s):  
Y.-J. Chang ◽  
Q. Zhou ◽  
W.-H. Hou ◽  
Y.-H. Liang ◽  
L. Ren ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Crosslinking Density ◽  
Nanofibrillated Cellulose ◽  
Magnetic Response ◽  
Cellulose Content ◽  
High Mechanical Strength ◽  
Strength Based ◽  
Swelling Rate ◽  
One Step ◽  
Soft Magnetism

Abstract Novel kinds of magnetism-driven poly N,N-dimethylacrylamide bilayer intelligent hydrogels with various nanofibrillated cellulose (NFC) contents were prepared successfully via one-step insitu free radical polymerization. The bilayer hydrogels possessed high mechanical strength, efficient swelling and steady magnetic response. With the increase of nanofibrillated cellulose content, the crosslinking density of the hydrogels increased, leading to the decrease of swelling rate and increase of mechanical strength and swelling bending degree of hydrogel actuators, respectively. Fe3O4 particles existed tightly on the micropore surfaces of the hydrogels, which built the function base of magnetic response of hydrogel actuators. The addition of Fe3O4 was irrelevant to the variation of crosslinking density. The bilayer structure exhibited high bonding strength. Based on intelligent responsive properties, bilayer hydrogels were designed as soft magnetism-driven actuators, realizing capture and transportation properties and provided material candidates for soft robots.

An alter-centric perspective on employee innovation: The importance of alters’ creative self-efficacy and network structure.

2017 ◽  
Vol 102 (9) ◽  
pp. 1360-1374 ◽  
Author(s):  
Travis J. Grosser ◽  
Vijaya Venkataramani ◽  
Giuseppe (Joe) Labianca
Keyword(s):  
Network Structure ◽  
Self Efficacy ◽  
Creative Self

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

Türkiye'de iller arası göçlerin nodexl ile sosyal ağ analizi

2017 ◽  
Vol 4 (1) ◽  
pp. 82-109 ◽  
Author(s):  
Mustafa Yakar ◽  
Fatma Sert Eteman
Keyword(s):  
Network Structure ◽  
Population Data ◽  
Single Mode ◽  
Turkish Population ◽  
Place Of Birth ◽  
Place Of Residence ◽  
Migration Flow ◽  
Population Structures ◽  
The Republic ◽  
Provincial Scale

Türkiye'de 20.yy'ın ortasından itibaren başlayan iç göçler zamanla kurulan göçmen ağları ile süreklilik kazanmış ve ülke içinde nüfusun kır-kent dağılımını değiştirecek boyutlara erişmiştir. Araştırma, göçün doğum yeri verisinden hareketle ikamet edilen yerdeki nüfus miktarına göre alınan ve verilen göç akışının büyüklüğünü iller ölçeğinde yönlü ağlar kullanılarak analiz edilmesini amaçlamaktadır. Araştırmada, TÜİK tarafından yayınlanmış olan 2015 yılına ait, iller ölçeğinde doğum yerine göre ikamet yeri verisi kullanılmıştır. Göçün kaynak ve hedef sahaları arasındaki akışını incelemek için NodeXL ile oluşturulan tek modlu, yönlü ve ağırlıklandırılmış göç ağının istatistiksel olarak tam ağ yapısına sahip olduğu görülmüştür. Ağ grafiklerinden ve istatistiklerinden göç hareketinin doğudan batıya doğru gerçekleştiği ve İstanbul’ un ülkenin tamamına hâkim bir görünüme sahip olduğu anlaşılmaktadır. Türkiye nüfusunun cumhuriyet tarihi içinde geçirdiği iç göç süreçleriyle birlikte ülke içinde kurulmuş ve oldukça karmaşık bir görünüme sahip ağ yapısının olduğu ileri sürülebilir. Kurulan ağlar göçlerin devamını sağladığı gibi, göçün yöneldiği merkezlerde daha heterojen nüfus yapılarının ortaya çıkmasına yol açmıştır.ABSTRACT IN ENGLISHSocial Network Analysis of Migration Inter Provinces In Turkey with Nodexl The internal migrations which started in Turkey in the middle of the 20th century have gained permanency with the migration networks that were established at the time and reached dimensions which have the potential to change the rural-urban distribution of the population within the country.  The study aims to analyze the magnitude of the incoming and outgoing migration flow at the provincial scale based on the population data for place of birth according to place of residence by using directional networks. Place of residence according to place of birth at the provincial scale data for 2015 published by TÜİK was used in the study. A single mode, directional and weighted migration network created with NodeXL to examine the migration flows between the source and target has a statistically complete network structure. The network graphs and statistics show that the migrations have taken place from east to west and Istanbul has a view as dominant of the country. It can be argued that internal network structure of Turkish population has  a very complex view because of internal migration in the history of the republic. The established networks have enabled the continuation of migration and have manifested as the emergence of more heterogeneous population structures in centers where migration had been directed.

Application of Fractal Methods to Ensure the Cyber-Resilience of Self-Organizing Networks

2019 ◽  
Vol 22 (4) ◽  
pp. 336-341
Author(s):  
D. V. Ivanov ◽  
D. A. Moskvin
Keyword(s):  
Information Security ◽  
Network Structure ◽  
Self Regulation ◽  
Security Threats ◽  
Self Organizing Networks ◽  
Self Organizing ◽  
Fractal Methods

In the article the approach and methods of ensuring the security of VANET-networks based on automated counteraction to information security threats through self-regulation of the network structure using the theory of fractal graphs is provided.

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