scholarly journals Preparation and Application of Cationic Modified Cellulose Fibrils as a Papermaking Additive

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yanhong Gao ◽  
Qun Li ◽  
Yu Shi ◽  
Ruitao Cha
Keyword(s):  
Zeta Potential ◽  
Chemical Properties ◽  
Cationic Starch ◽  
Physical Strength ◽  
Tensile Index ◽  
Tear Index ◽  
Colloid Titration ◽  
Cellulose Fibrils ◽  
Physical And Chemical ◽  
Modified Cellulose

This paper deals with cationic modified cellulose fibrils obtained by reacting the cellulose fibrils with 2,3-epoxypropyltrimethylammonium chloride (EPTMAC). The physical and chemical properties of unmodified cellulose fibrils (UMCF) and cationic modified cellulose fibrils (CMCF) were characterized by SEM, FTIR, degree of substitution, colloid titration, zeta potential, and thermogravimetric analysis. The experimental results showed that, after cationization, surface charge density and zeta potential reversed, thermal stability decreased, and new functional groups appeared, while the surface morphology did not show much difference from the UMCF. With the addition of three kinds of additives (UMCF, CMCF, and cationic starch (CS)) to BCTMP, the addition of UMCF and CMCF had little effect on zeta potential, while the addition of CS changed zeta potential obviously. With the increasing of additive amount, the bulk of paper sheets added CMCF did not change obviously, while the bulk of paper sheets added UMCF and CS decreased rapidly. With regard to physical strength, all the three kinds of additives could improve the tensile index and tear index; the tensile index of paper sheets added CS was higher than that of added UMCF and CMCF, while the tear index of paper sheets added CMCF was the highest among the three additives.

scholarly journals Enhancement of As(v) adsorption from aqueous solution by a magnetic chitosan/biochar composite

RSC Advances ◽  
2017 ◽  
Vol 7 (18) ◽  
pp. 10891-10900 ◽  
Author(s):  
Shaobo Liu ◽  
Binyan Huang ◽  
Liyuan Chai ◽  
Yunguo Liu ◽  
Guangming Zeng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Zeta Potential ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Magnetic Chitosan ◽  
Physical And Chemical ◽  
And Chemical Properties

In this study, a magnetic chitosan/biochar composite (MCB) was prepared successfully, and characterized by SEM, TEM, VSM, XRD, FTIR, XPS, and zeta-potential to obtain its physical and chemical properties.

scholarly journals ESTUDO DA QUÍMICA DE SUPERFÍCIE PARA SELEÇÃO DE PROTETIVOS HIDRORREPELENTES E SUPORTE TECNOLÓGICO PARA CONSERVAÇÃO E RESTAURO DE BENS PÉTREOS

2016 ◽  
Author(s):  
Daniel Silva Barbutti ◽  
Roberto Carlos da Conceição Ribeiro
Keyword(s):  
Zeta Potential ◽  
Protective Coatings ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Technological Support ◽  
X Ray ◽  
Before And After ◽  
Ph Range ◽  
Physical And Chemical ◽  
Selection Of

ResumoNeste estudo foram avaliadas as interações entre três representantes minerais constituintes das rochas ornamentais graníticas (quartzo, microclina e muscovita) e três protetivos comerciais com propriedades hidrorrepelentes. Os minerais foram caracterizados química e mineralogicamente por análises de fluorescência e difração de Raios-X (FRX e DRX, respectivamente), enquanto os protetivos foram caracterizados por meio de espectroscopia de infravermelho com transformada de Fourier (FTIR). Para avaliação da eficácia dos protetivos, foram realizados estudos de mobilidade eletroforética a partir da avaliação do potencial zeta dos minerais em função do pH, antes e após tratamento com cada produto. Os resultados indicaram melhor desempenho do protetivo a base de siloxano, reduzindo a eletronegatividade da superfície de todos os minerais, principalmente na faixa levemente ácida de pH entre 3 e 6, onde ocorrem os principais intemperismos capazes de alterar as propriedades físico-químicas de rochas expostas em centros urbanos. Foram visualizadas reduções médias de até 15mV para quartzo, 5 mV para muscovita e 20 mV para microclina. Análises prévias das rochas de um monumento e dos protetivos inicialmente elegidos para proteção são importantes para a correta conservação e restauro dos bens pétreos que resguardam seus valores artísticos e culturais. Palavras Chave: conservação e restauro, potencial zeta, mineral AbstractSURFACE CHEMISTRY STUDY FOR THE SELECTION OF HYDRORPEPEAL PROTEINS AND TECHNOLOGICAL SUPPORT FOR CONSERVATION AND RESTORATION OF STONE ASSETS. Interactions between the main minerals that compose the granitic dimension stones (quartz, microcline and muscovite) and three commercial hydrophobic protective coatings were investigated in this study. The minerals were characterized chemically and mineralogically through fluorescence X-ray analysis (XRF) and X-ray diffraction (XRD) respectively, while the protective coatings were characterized by Fourier transform infrared spectroscopy (FTIR). The interactions between minerals and protective coatings were evaluated by zeta potential measurements of the minerals as a function of pH before and after surface treatment with each product. The results showed that only one protective coating was able to reduce the electronegativity in all mineral samples, especially in mildly acidic pH range, where several outdoor weathering effects occur, modifying the physical and chemical properties of stone-built monuments in urban environment. Previous analysis of the stones that constitute the monument as well as preselected products for its treatment are considered important to guide the proper conservation and restoration of stone-built cultural heritages that enshrine their artistic and historical values. Keywords: conservation & restoration, zeta potential, mineral

Modification of Bleached Softwood Pulp with Xylanase

2011 ◽  
Vol 393-395 ◽  
pp. 855-858
Author(s):  
Min Du ◽  
Xin Ping Li ◽  
Wu Guang Li
Keyword(s):  
Zeta Potential ◽  
Fiber Length ◽  
Fiber Surface ◽  
Enzymatic Treatment ◽  
Surface Wettability ◽  
Refining Efficiency ◽  
Tensile Index ◽  
Tear Index ◽  
Softwood Pulp ◽  
Enzyme Dosage

Xylanse named as Pulpzyme HC was used to modify bleached softwood pulp before refining. The efficiency of modification by different enzyme dosage was invested in this paper. The result showed that enzymatic treatment decreased the dissolved charge and absolute Zeta potential of the slurry and increased the fiber surface wettability. Appropriate Pulpzyme HC (0.4u/g) could improve the refining efficiency by 9.5°SR. The brightness and bulk of hand sheets increased with the increasing of the enzyme. Tensile index and tear index of hand sheets reached the maximum at the enzyme dosage of 0.2u/g. In this dosage, fiber length, knot index and curl index of fiber increased. But excessive enzyme decreased the tear index and had no effect on the tensile index.

scholarly journals Influence of cellulose particles on chemical resistance, mechanical and thermal properties of epoxy composites

2020 ◽  
Keyword(s):  
Epoxy Resin ◽  
Chemical Resistance ◽  
Chemical Properties ◽  
Mechanical And Thermal Properties ◽  
Physical And Chemical Properties ◽  
Plant Materials ◽  
Physical And Chemical ◽  
Thermal Stability Of ◽  
Modified Cellulose ◽  
And Chemical Properties

Background: The technological developments for nanocellulose production from cheaper plant materials compared to wood, in particular, agricultural waste is an urgent task of nanobiophysics. The discovery of possibility of expanding the functional characteristics of materials in compositions with modified cellulose particles essentially stimulated the interest of researchers in cellulose composites. Surface modification of cellulose particles by functional materials, such as dyes, metal oxides, silicon, allows applying composites with modified cellulose in various areas of modern industry. A significant improvement in the operational performances of functionalized cellulose particles can be achieved by using them as filler in polymers. Epoxy resin compositions with modified and unmodified cellulose particles, studied in present work, are an example of hybrid biosystem. The interfacial interaction of filler particles with the epoxy matrix, their concentration and dispersion can change the physical and chemical properties of the biopolymer and the functional parameters of biocomposites. Studying the influence of external fields on the physical and chemical properties of epoxy resin-based biosystems and their influence on operational parameters seems to be an urgent problem of advanced and sustained materials science. Objectives: The purpose of this work was to develop an effective nanocellulose synthesis from plant materials and surface functionalization of micro- and nanocellulose particles with clathrochelate iron (ΙΙ) dye as well obtaining biocompositions of epoxy resin with functionalized and non-functionalized micro- and nanocellulose, and to explore of the morphology, chemical resistance, mechanical and thermal properties of epoxy composites with cellulose micro and nanoparticles. Materials and methods: The studying objects were the composites of epoxy resin Eposir-7120 with a polyethylene polyamine “PEPA” hardener in a ratio of 6.2:1 and 10% cellulose micro and nanoparticles. The microcellulose obtained from wood has been a commercial product. Nanocellulose has been synthesized from organosolv cellulose obtained from Miscanthus x giganteus stalks. Surface modification of micro- and nanocellulose was performed using the clathrochelate iron (ΙΙ) dye. The specific surface area of cellulose particles was determined using low-temperature nitrogen adsorption-desorption according to the Brunauer-Emmett-Teller method. Mechanical parameters were determined using universal Shopper and UMM-10 machines. Thermal analysis was performed using Q1500 analyzer. Swelling was determined by the gravimetric method. Results: Elastic modulus E, compressive strength σ and thermogravimetric parameters were determined. It was shown that in composites with micro and nanocellulose the E rises in 7.0–12.2% while the σ increases in 9.1% for composites with cellulose micro particles. The loading resin with nanocellulose and modified cellulose microparticles no affects the σ value of composites. The thermal stability of epoxy polymer (310°C) reduces after loading with micro and nanocellulose to 290 and 300°C, respectively. Chemical resistance of composites with both celluloses to 20% nitric acid reduces. In neutral medium swelling characterizes by rapid sorption to saturation of 15–20% acetone in 36 hours. Conclusions: Thus, the synthesis method of nanocellulose from plant materials and functionalization of its surface with clathrochelate iron (ΙΙ) were developed. Light response of dye was detected in visible spectral range. Epoxy resin composites with 10% micro and nanocellulose were obtained. The filling effect with micro- and nanocellulose at elastic modulus, compressive strength, and thermal stability of epoxycomposites was studied. The swelling processes run similarly in composites with cellulose micro and nanoparticles.

New Strength Agent: Corn Stalk Pulp Applied on Package Board

2013 ◽  
Vol 734-737 ◽  
pp. 2094-2099
Author(s):  
Jie Zheng ◽  
Guang Wei Sun ◽  
Shi Jie Zhang ◽  
Fu Zheng Liang ◽  
Shuo Hu
Keyword(s):  
Physical Properties ◽  
Process Parameters ◽  
Corn Stalk ◽  
Physical Strength ◽  
Tensile Index ◽  
Tear Index ◽  
Mineral Fibre

The feasibility of making new strength agent by cooking corn stalk rich in hemicellulose was studied. Corn stalk was cooked by normal ethanol pulping with best process parameters obtained by early discovery. The effect of corn stalk agent on physical strength of package board (made by 20% mineral fibre and 80% recycled fibre) was discussed as well. After cooked, all of the corn stalk suspension was added into the mixed pulp directly. Results showed that the package boards physical properties improved greatly. Tensile index, ring crush index, bursting index and folding index increased by 39.6%, 35.4%, 26.6% and 100% respectively at dosage of 5% while tear index and tightness changed slightly under the same conditions.

Nanocrystallites in urine and their relationship with the formation of kidney stones

2012 ◽  
Vol 32 (2-4) ◽  
pp. 101-110 ◽  
Author(s):  
Jian-Ming Ouyang ◽  
Zhi-Yue Xia ◽  
Guang-Na Zhang ◽  
He-Qun Chen
Keyword(s):  
Chemical Composition ◽  
Zeta Potential ◽  
Kidney Stones ◽  
Chemical Properties ◽  
Healthy Controls ◽  
Physical And Chemical Properties ◽  
Aggregation Size ◽  
Physical And Chemical ◽  
The Relationship ◽  
And Chemical Properties

AbstractKidney stones are mainly composed of inorganic crystals such as calcium oxalate (CaOxa). At present, kidney stones can be detected only after their formation, which causes great suffering for patients. If kidney stones can be detected prior to their formation, they can be effectively prevented, which presents great commercial value. In this paper, we review the differences in urine nanocrystallites between stone-forming patients and healthy controls, as well as the relationship between nanocrystallites in urine and the formation of kidney stones. These differences are microcrystalline morphology, aggregation, size and distribution, chemical composition, Zeta potential and stability. The results showed that the formation of kidney stones is closely related to the nature of nanocrystallites. Through the regulation of the physical and chemical properties of nanocrystallites, the formation and recurrence of kidney stones are possibly inhibited.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Biophysical Measurement of Molecular Weight of Foot-and-Mouth Disease RNA Fragments

1974 ◽  
Vol 32 ◽  
pp. 262-263
Author(s):  
Sydney S. Breese ◽  
Howard L. Bachrach
Keyword(s):  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distilled Water ◽  
Bovine Plasma ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Carbon Coated ◽  
Rna Fragments ◽  
Physical And Chemical

Continuing studies on the physical and chemical properties of foot-and-mouth disease virus (FMDV) have included electron microscopy of RNA strands released when highly purified virus (1) was dialyzed against demlneralized distilled water. The RNA strands were dried on formvar-carbon coated electron microscope screens pretreated with 0.1% bovine plasma albumin in distilled water. At this low salt concentration the RNA strands were extended and were stained with 1% phosphotungstic acid. Random dispersions of strands were recorded on electron micrographs, enlarged to 30,000 or 40,000 X and the lengths measured with a map-measuring wheel. Figure 1 is a typical micrograph and Fig. 2 shows the distributions of strand lengths for the three major types of FMDV (A119 of 6/9/72; C3-Rezende of 1/5/73; and O1-Brugge of 8/24/73.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

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