scholarly journals Surface Modification on Cellulose Nanofibers by TiO2 Coating for Achieving High Capture Efficiency of Nanoparticles

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 139 ◽  
Author(s):  
Chenning Zhang ◽  
Tetsuo Uchikoshi ◽  
Izumi Ichinose ◽  
Lihong Liu
Keyword(s):  
Surface Modification ◽  
Surface Charge ◽  
Electrostatic Interaction ◽  
Au Nanoparticles ◽  
High Efficiency ◽  
Cellulose Nanofibers ◽  
Filtration Efficiency ◽  
Tio2 Coating ◽  
Gel Layer ◽  
Tio2 Gel

Cellulose nanofibers were modified by TiO2 gel layer (~25 nm in thickness) via hydrolysis reaction on the surface of the cellulose nanofibers. After the TiO2 coating, the surface charge of the nanofiber dramatically changed from negative to positive. A high efficiency (~100%) of capturing negatively charged Au nanoparticles (5 nm) was successfully obtained by effectively utilizing the electrostatic interaction of surface charge between the TiO2-coated cellulose nanofibers and Au nanoparticles. Therefore, this technique of surface modification will be potentially used in improving filtration efficiency for membrane applications.

scholarly journals Effect of Surface Modification with TiO2 Coating on Improving Filtration Efficiency of Whisker-Hydroxyapatite (HAp) Membrane

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 670
Author(s):  
Chenning Zhang ◽  
Tetsuo Uchikoshi ◽  
Lihong Liu ◽  
Masanori Kikuchi ◽  
Izumi Ichinose
Keyword(s):  
Surface Modification ◽  
Hydrothermal Synthesis ◽  
Zeta Potential ◽  
Au Nanoparticles ◽  
Particle Growth ◽  
Filtration Efficiency ◽  
Tio2 Coating ◽  
Free Standing ◽  
Positively Charged ◽  
Effect Of Surface

Whisker-like hydroxyapatite (HAp) particles were prepared by controlling particle growth via hydrothermal synthesis. The surface modification for the hydrothermally synthesized HAp whiskers was accomplished by TiO2 coating. After the TiO2 modification, the zeta potential of the HAp whiskers was significantly improved from +8.6 to +21 mV at pH = 8.5. A free-standing membrane (diameter of ~4.5 cm and thickness of ~0.2 mm) was fabricated by using the TiO2-coated HAp whiskers and was used to separate the Au nanoparticles (size = 5 nm and zeta potential = −38.6 mV at pH = 8.5) at a significantly high filtration efficiency of ~100%. The achieved high filtration efficiency was considered to be the result of effectively utilizing the electrostatic interaction between the positively-charged TiO2-coated HAp whiskers and negatively-charged Au nanoparticles. The excellently biocompatible and highly effective TiO2-coated HAp membrane would be potentially applied as biological and artificial separators in biotechnology processes for the biomedicine field.

Surface Charge Modification of Nano-Sized Silica Colloid

2007 ◽  
Vol 60 (9) ◽  
pp. 662 ◽  
Author(s):  
Khoa N. Pham ◽  
Damian Fullston ◽  
Kwesi Sagoe-Crentsil
Keyword(s):  
Surface Modification ◽  
Surface Charge ◽  
High Specific Surface Area ◽  
High Concentration ◽  
Factors Affecting ◽  
Gel Layer ◽  
Aqueous Solvent ◽  
Before And After ◽  
Irreversible Aggregation ◽  
Stable Particles

The surface of commercial 30-nm colloidal silica particles were modified by reaction with functional silanes. The high specific surface area and reactivity of the particles, due to their small size, makes the process susceptible to irreversible aggregation not found previously with larger particles. The present study compares surface charge results from amino silanes with one or three alkoxy groups. Measurements of the zeta potential as a function of pH, and gelation kinetics shed light on the mechanism of surface charge changes from the modification. Instability in suspensions before and after the surface modification is also studied using a new data analysis technique from simple light-scattering equipment. Experimental results show very stable particles are obtained by amino silane surface modification. Factors affecting susceptibility of small particles to irreversible aggregation caused by a non-aqueous solvent or high concentration of a trialkoxy silane, including the large number of reactive silanol groups in the surface gel layer of the particles, are discussed.

scholarly journals Construction of the Cellulose Nanofibers (CNFs) Aerogel Loading TiO2 NPs and Its Application in Disposal of Organic Pollutants

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1841
Author(s):  
Kang Li ◽  
Xuejie Zhang ◽  
Yan Qin ◽  
Ying Li
Keyword(s):  
High Efficiency ◽  
Sol Gel ◽  
Cellulose Nanofibers ◽  
Three Dimensional ◽  
Good Mechanical Property ◽  
Polar Groups ◽  
Dimensional Network ◽  
Natural Polysaccharide ◽  
Valuable Method ◽  
Adsorption Capability

Aerogels have been widely used in the adsorption of pollutants because of their large specific surface area. As an environmentally friendly natural polysaccharide, cellulose is a good candidate for the preparation of aerogels due to its wide sources and abundant polar groups. In this paper, an approach to construct cellulose nanofibers aerogels with both the good mechanical property and the high pollutants adsorption capability through chemical crosslinking was explored. On this basis, TiO2 nanoparticles were loaded on the aerogel through the sol-gel method followed by the hydrothermal method, thereby the enriched pollutants in the aerogel could be degraded synchronously. The chemical cross-linker not only helps build the three-dimensional network structure of aerogels, but also provides loading sites for TiO2. The degradation efficiency of pollutants by the TiO2@CNF Aerogel can reach more than 90% after 4 h, and the efficiency is still more than 70% after five cycles. The prepared TiO2@CNF Aerogels have high potential in the field of environmental management, because of the high efficiency of treating organic pollutes and the sustainability of the materials. The work also provides a choice for the functional utilization of cellulose, offering a valuable method to utilize the large amount of cellulose in nature.

scholarly journals A self-boosting microwave plasma strategy tuned by air pressure for the highly efficient and controllable surface modification of carbon

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9955-9963
Author(s):  
Yanjing Liu ◽  
Jiawei He ◽  
Bing Zhang ◽  
Huacheng Zhu ◽  
Yang Yang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Carbon Fiber ◽  
High Efficiency ◽  
Microwave Plasma ◽  
Air Pressure ◽  
Air Plasma ◽  
Highly Efficient ◽  
Carbon Fiber Cloth

Microwave enabled air plasma was boosted by a carbon fiber cloth (CFC) and used for the high-efficiency surface modification of the CFC, yielding CFCs with tunable contents of oxygen and each O-containing group.

Synergistic Promotion of Photoelectrochemical Water Splitting Efficiency of TiO2 Nanorod Arrays by Doping and Surface Modification

2021 ◽  
Author(s):  
Liang Zhao ◽  
Ding Chen ◽  
Shang Xu ◽  
Zhi Fang ◽  
Lin Wang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Surface Charge ◽  
Water Splitting ◽  
Charge Recombination ◽  
Photoelectrochemical Water Splitting ◽  
Nanorod Arrays ◽  
Critical Factors ◽  
Tio2 Nanorod ◽  
Tio2 Nanorod Arrays ◽  
Light Capture

Fast surface charge recombination and poor light capture capability are regarded as the two critical factors that hamper the photoelectrochemical (PEC) performance of photoanodes. In the present work, we employed...

scholarly journals Electric Field Assisted Femtosecond Laser Preparation of Au@TiO2 Composites with Controlled Morphology and Crystallinity for Photocatalytic Degradation

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3816
Author(s):  
Xiaojie Li ◽  
Xin Li ◽  
Pei Zuo ◽  
Xiaozhe Chen ◽  
Misheng Liang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Electric Field ◽  
Photocatalytic Degradation ◽  
Au Nanoparticles ◽  
High Efficiency ◽  
Free Electron Density ◽  
Pulse Delay ◽  
Dye Pollutants ◽  
Amorphous Tio2 ◽  
Laser Liquid

TiO2 is popular in photocatalytic degradation dye pollutants due to its abundance and its stability under photochemical conditions. Au loaded TiO2 can achieve efficient absorption of visible light and deal with the problem of low conversion efficiency for solar energy of TiO2. This work presents a new strategy to prepare Au nanoparticles-loaded TiO2 composites through electric−field−assisted temporally−shaped femtosecond laser liquid-phase ablation of Au3+ and amorphous TiO2. By adjusting the laser pulse delay and electric field parameters, gold nanoparticles with different structures can be obtained, such as nanospheres, nanoclusters, and nanostars (AuNSs). AuNSs can promote the local crystallization of amorphous TiO2 in the preparation process and higher free electron density can also be excited to work together with the mixed crystalline phase, hindering the recombination between carriers and holes to achieve efficient photocatalytic degradation. The methylene blue can be effectively degraded by 86% within 30 min, and much higher than the 10% of Au nanoparticles loaded amorphous TiO2. Moreover, the present study reveals the crystallization process and control methods for preparing nanoparticles by laser liquid ablation, providing a green and effective new method for the preparation of high-efficiency photocatalytic materials.

Surface Modification of Bacterial Cellulose Nanofibers for Property Enhancement of Optically Transparent Composites:  Dependence on Acetyl-Group DS

2007 ◽  
Vol 8 (6) ◽  
pp. 1973-1978 ◽  
Author(s):  
Shinsuke Ifuku ◽  
Masaya Nogi ◽  
Kentaro Abe ◽  
Keishin Handa ◽  
Fumiaki Nakatsubo ◽  
...  
Keyword(s):  
Surface Modification ◽  
Bacterial Cellulose ◽  
Cellulose Nanofibers ◽  
Optically Transparent ◽  
Acetyl Group ◽  
Transparent Composites

scholarly journals Hybrid Monolith of Graphene/TEMPO-Oxidized Cellulose Nanofiber as Mechanically Robust, Highly Functional, and Recyclable Adsorbent of Methylene Blue Dye

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Asif Hussain ◽  
Jiebing Li ◽  
Jun Wang ◽  
Fei Xue ◽  
Yundan Chen ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Charge Density ◽  
Surface Charge ◽  
Surface Area ◽  
Specific Surface Area ◽  
Surface Charge Density ◽  
Cellulose Nanofibers ◽  
Maximum Adsorption Capacity ◽  
Assembly Method

Herein we demonstrate first report on fabrication, characterization, and adsorptive appraisal of graphene/cellulose nanofibers (GO/CNFs) monolith for methylene blue (MB) dye. Series of hybrid monolith (GO/CNFs) were assembled via urea assisted self-assembly method. Hybrid materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction patterns, Raman spectroscopy, elemental analysis, thermogravimetric curve analysis, specific surface area, surface charge density measurement, and compressional mechanical analysis. It was proposed that strong chemical interaction (mainly hydrogen bonding) was responsible for the formation of hybrid assembly. GO/CNFs monolith showed mechanically robust architecture with tunable pore structure and surface properties. GO/CNFs adsorbent could completely remove trace to moderate concentrations of MB dye and follow pseudo-second-order kinetics model. Adsorption isotherm behaviors were found in the following order: Langmuir isotherm > Freundlich isotherm > Temkin isotherm model. Maximum adsorption capacity of 227.27 mg g−1 was achieved which is much higher than reported graphene based monoliths and magnetic adsorbent. Incorporation of nanocellulose follows exponential relationship with dye uptake capacities. High surface charge density and specific surface area were main dye adsorptive mechanism. Regeneration and recycling efficiency was achieved up to four consecutive cycles with cost-effective recollection and zero recontamination of treated water.

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