Effect of the glass-transition temperature of latexes on drying-stress development of latex films and inkjet coating layers

2020 ◽  
Vol 35 (4) ◽  
pp. 660-669 ◽  
Author(s):  
SangGil Lee ◽  
Sunhyung Kim ◽  
Hak Lae Lee
Keyword(s):  
Crack Formation ◽  
Coating Layer ◽  
Porous Silica ◽  
Sudden Increase ◽  
Drying Temperature ◽  
Stress Development ◽  
Coated Papers ◽  
Coating Layers ◽  
Stress Patterns ◽  
Highly Porous

AbstractHighly porous silica pigments and PVOH binder are commonly used for inkjet coated papers. The use of PVOH increases the viscosity of coating colours and increases drying stresses in the coatings. In this study, the possibility of using S/A lattices as inkjet binders to decrease the viscosity of inkjet coatings and meet the quality requirements of the inkjet papers was investigated. Three S/A latices were prepared and tested as binders for inkjet coating. The effect of drying temperature and binder {T_{\mathrm{g}}} on the drying stress development and crack formation in the coating was investigated. The results showed that the {T_{\mathrm{g}}} of S/A latices, drying temperature, and PVC influenced the drying-stress patterns during drying. Drying stress decreased as the {T_{\mathrm{g}}} of the latex decreased and the drying temperature increased. The presence of silica pigment caused a sudden increase and then decrease of the drying stress due to cracking of the coating layer. Two S/A latices gave coating colours with lower Brookfield viscosities and drying stresses than conventional PVAc latex, and they also gave coatings similar in brightness, opacity, gloss and roughness to the conventional latex coating.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

Sol-Gel Derived Silica Layers for Low-k Dielectrics Applications

2000 ◽  
Vol 612 ◽  
Author(s):  
Sylvie Acosta ◽  
André Ayral ◽  
Christian Guizard ◽  
Charles Lecornec ◽  
Gérard Passemard ◽  
...  
Keyword(s):  
Average Pore Size ◽  
Sol Gel ◽  
Porous Silica ◽  
Thin Layers ◽  
Gaseous Ammonia ◽  
Potential Candidate ◽  
Average Pore ◽  
Synthesis Strategy ◽  
Silica Layers ◽  
Highly Porous

AbstractPorous silica exhibits attractive dielectric properties, which make it a potential candidate for use as insulator into interconnect structures. A new way of preparation of highly porous silica layers by the sol-gel route was investigated and is presented. The synthesis strategy was based on the use of common and low toxicity reagents and on the development of a simple process without gaseous ammonia post-treatment or supercritical drying step. Defect free layers were deposited by spin coating on 200 mm silicon wafers and characterized. Thin layers with a total porosity larger than 70% and an average pore size of 5 nm were produced. The dielectric constant measured under nitrogen flow on these highly porous layers is equal to ∼ 2.5, which can be compared to the value calculated from the measured porosity, ∼ 1.9. This difference is explained by the presence of water adsorbed on the hydrophilic surface of the unmodified silica.

Incorporation of Anatase TiO 2 to Highly Porous Silica (BMMs) for Photo‐Degradation of Alizarin Red Dye in Aqueous Solution

2021 ◽  
Vol 6 (26) ◽  
pp. 6816-6825
Author(s):  
Anadil Gul ◽  
Jihong Sun ◽  
Raza Ullah ◽  
Tallat Munir ◽  
Shiyang Bai
Keyword(s):  
Aqueous Solution ◽  
Porous Silica ◽  
Alizarin Red ◽  
Photo Degradation ◽  
Red Dye ◽  
Highly Porous

scholarly journals Microstructure of Joint between Stranded Wire and Substrate Welded by Ultrasonic Welding

2019 ◽  
Vol 9 (3) ◽  
pp. 534 ◽  
Author(s):  
Chihiro Iwamoto ◽  
Keisuke Yamauchi ◽  
Kazuki Motomura ◽  
Yoichi Hashimoto ◽  
Kensuke Hamada
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Coating Layer ◽  
Ultrasonic Welding ◽  
Efficient Technique ◽  
High Quality ◽  
Cu Substrate ◽  
Coating Layers ◽  
Microscopy Techniques

In order to improvement electronic and mechanical properties, welding between stranded wires and terminals is important. However, welding methods to obtain high-quality joints using stranded wires are still limited. In this report, we applied ultrasonic welding to join a Cu stranded wire to a Cu substrate. Cross-sections of the weldments were taken and observed by several microscopy techniques to elucidate the weldability and soundness of the joints. After ultrasonic welding, each wire in the stranded wire was joined together at the region where the stranded wire was joined to the substrate without any defect. Each wire was welded through the Ag coating layer, and the stranded wire and the substrate was also welded through the outermost coating layers. It was found that ultrasonic welding is an efficient technique for producing high quality joints without any defect at the interface.

Solution blow spun spinel ferrite and highly porous silica nanofibers

2018 ◽  
Vol 44 (9) ◽  
pp. 10984-10989 ◽  
Author(s):  
Rosiane Maria da Costa Farias ◽  
Lucas Leite Severo ◽  
Danubia Lisboa da Costa ◽  
Eliton Souto de Medeiros ◽  
Gregory M. Glenn ◽  
...  
Keyword(s):  
Spinel Ferrite ◽  
Porous Silica ◽  
Silica Nanofibers ◽  
Highly Porous

Mechanically Strong and Hierarchical Porous Silica Ceramics via Gelcasting-Lyophilization

2016 ◽  
Vol 697 ◽  
pp. 414-418
Author(s):  
Wei Wan ◽  
Jian Yang ◽  
Yong Bao Feng ◽  
Tai Qiu
Keyword(s):  
Raw Materials ◽  
Aqueous Suspension ◽  
Three Dimensional ◽  
Porous Silica ◽  
Hierarchical Porous ◽  
Exhaust Fumes ◽  
Materials Used ◽  
Gelcasting Process ◽  
Hierarchical Pore ◽  
Highly Porous

Highly porous silica ceramics were prepared by in-situ gelation of an aqueous suspension with well dispersed silica particles and N’N-dimethylacrylamide (DMAA) monomer, followed by lyophilization and pressureless sintering. The gelcasting process was imparted by polymerization of DMAA. The silica raw materials used in this experiment are the dusts collected from the exhaust fumes of silicon industry. The as-obtained porous silica ceramics had three-dimensional and hierarchical pore structure and the porosity ranged from 75 to 88 % as the sintering temperature varied from 850 to 1050 °C. In addition, the porous silica ceramics appeared to have strong mechanical strength. Compressive strength of the porous silica ceramics was as high as 3.2 MPa even when the porosity was nearly 80%. The gelcasting-lyophilization method was proved to be a novel and promising route for the preparation of highly porous and mechanically strong materials.

Resorption Mechanism of Hydroxyapatite and β-Tricalcium Phosphate Coating Layer

2008 ◽  
Vol 396-398 ◽  
pp. 81-84 ◽  
Author(s):  
Kang Sik Lee ◽  
Jae Suk Chang ◽  
Jung Hwa Kim ◽  
Chang Kuk You ◽  
Hoon Kwon ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Coating Layer ◽  
Culture Media ◽  
In Vitro Study ◽  
Cell Culture Media ◽  
Beta Tricalcium Phosphate ◽  
Ha Coating ◽  
Coating Method ◽  
Coating Layers

Beta-tricalcium phosphate(β-TCP) coating layer is known to be resorbed much faster than hydroxyapatite(HA), however, there has been no report to explain the exact reason of these results. Eighty titanium discs, coated with HA(n=40) or β-TCP(n=40) by dip and spin coating method, were divided into 2 subgroups respectively; Dissolution(D, n=20) and osteoclast culture(C, n=20). The coated discs in D group were immersed in the cell culture media for 5 days, whereas, in C group, osteoclasts were seeded on the specimens and cultured for 5 days. After simple dissolution test, β-TCP coating layer showed much more cracks and denudation as compared to HA. In osteoclast culture group, mean area fraction of resorption pits in HA-C group was 11.62%, which was significantly higher than that of 0.73% in β-TCP-C group(p=0.001). In conclusion, the resorption mechanisms of HA and β-TCP coating layers were different each other in vitro study. The coated β-TCP was degraded mainly by dissolution and separation from implant, on the other hand, the HA coating layer was resorbed by osteoclastic activity.

Highly Porous Silica Nanoaerogels for Ultrafast Nonlinear Optical Applications

2005 ◽  
Vol 287 ◽  
pp. 352-357 ◽  
Author(s):  
Jae Tae Seo ◽  
S.M. Ma ◽  
K. Lee ◽  
H. Brown ◽  
A. Jackson ◽  
...  
Keyword(s):  
Apparent Density ◽  
Homeland Security ◽  
Sol Gel ◽  
Nonlinear Refraction ◽  
Porous Silica ◽  
Signal Beam ◽  
Supercritical Fluid Drying ◽  
Optical Applications ◽  
Nonlinear Optical Applications ◽  
Highly Porous

Highly porous silica nanoaerogels with low apparent density of ~0.1 g/cm3 and ~0.07 g/cm3 were synthesized through two-step sol-gel processing and low temperature supercritical fluid drying. The nonlinear refraction (γ) of silica nanoaerogels was estimated to be ~ -3.4 x 10-16 m2/W for ~0.1 g/cm3 and ~0.07 g/cm3 apparent densities with a signal-beam femtosecond z-scan spectroscopy. The third-order nonlinear refraction coefficient of nanostructure silica nanoaerogels was almost four orders larger than that of bulk silica materials. The large nonlinearrefraction with high nonlinear figure of merit (γ/βλ, β~2×10-10 m/W for 0.07 g/cm3 apparent density, β~6×10-10 m/W for 0.1 g/cm3 apparent density, λ~0.775 µm) is an ideal optical property for nonlinear applications of homeland security, battlefield enhancement, and industrial uses.

Bimetallic FeCo Nanocrystals Supported on Highly Porous Silica Aerogels as Fischer–Tropsch Catalysts

2012 ◽  
Vol 142 (9) ◽  
pp. 1061-1066 ◽  
Author(s):  
Danilo Loche ◽  
Maria F. Casula ◽  
Anna Corrias ◽  
Sergio Marras ◽  
Pietro Moggi
Keyword(s):  
Porous Silica ◽  
Silica Aerogels ◽  
Fischer Tropsch ◽  
Highly Porous

Coating Binder Migration and Affected Parameters: Influence of Coating Process

2013 ◽  
Vol 791-793 ◽  
pp. 187-191
Author(s):  
Zhao Hui Zhen ◽  
Zheng Shun Wang
Keyword(s):  
Cross Section ◽  
Dwell Time ◽  
Coating Layer ◽  
Drying Rate ◽  
Coating Process ◽  
Coated Paper ◽  
Drying Temperature ◽  
Coating Surface ◽  
Binder Concentration ◽  
Coating Weight

The coating binder in cross-section of coating layer will be migrated, the binder concentration will be different in z-direction of coating layer, which affect some properties of coated paper. The paper studied the effects of coating progress on binder migration and affected factors. The z-direction distribution of the coating binder which was tagged with Br in coating layer and its concentration in coating surface were examined quantitatively by using SEM-EDXA and ESCA analysis. During coating process the drying rate, dwell time from coating device to dryer and coating weight affect the binder migration. The mechanism of binder migration was proposed. The results indicated that the degree of binder migration is directly proportional to the drying temperature and coating weight, but reduces with extending the dwell time.

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