Preparation of Very Thin Zinc Oxide Films by Liquid Deposition Process: Review of Key Processing Parameters

We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating agent, the nature of the solvent and the substrate material have been identified as key parameters that determine the microstructure of the deposited layer and thus its final properties. The thorough and practical examination of the effects of the synthesis parameters evidenced a three-step growth mechanism for these ZnO thin films: (i) a reaction of precursors, (ii) a formation of nuclei, and (iii) a coalescence of nanoparticles under thermal annealing. The growth of these very thin films is thus conditioned by the interaction between the liquid phase and the substrate especially during the initial steps of the spin coating process. Such thin ZnO films with such nano-granular morphology may be of great interest in various applications, especially those requiring a large active surface area.

Investigation into integration of digital manufacturing with ceramics

<p>Within the territory of crafts, it has long been thought that individuals’ proficiency and adeptness, which take long to attain or are presumably innate abilities, determine the quality, delicacy and value of the products, and the common perception has often acted as a barrier to accessibility and penetration. It is more apparent in the pottery and ceramics where special equipment and facilities, such as wheels and kilns, in addition to skilfulness and dexterity are considered essential for creation. Advances in digital technology represented by 3D printing, however, are changing the way objects are designed, produced and distributed, instigating attempts to view traditional crafting processes and practices from a different perspective. Among various branches of crafts, this research specifically explores introduction of digital technology to pottery and challenges the limitations that the conventional methods have, by eliminating the hardware restrictions and lowering the barriers. The outcome offers not only transcendent possibilities of creation to craftspeople and artists but also unprecedented accessibility and apprehensible process to the public. Technically, Liquid Deposition Modelling (LDM) building upon material optimisation and tool redesign was employed in conjunction with digital design process. In addition, functional additives were trialled to incorporate multilevel translucency and electrical conductivity into the new types of ceramic objects.</p>

Investigation into integration of digital manufacturing with ceramics

<p>Within the territory of crafts, it has long been thought that individuals’ proficiency and adeptness, which take long to attain or are presumably innate abilities, determine the quality, delicacy and value of the products, and the common perception has often acted as a barrier to accessibility and penetration. It is more apparent in the pottery and ceramics where special equipment and facilities, such as wheels and kilns, in addition to skilfulness and dexterity are considered essential for creation. Advances in digital technology represented by 3D printing, however, are changing the way objects are designed, produced and distributed, instigating attempts to view traditional crafting processes and practices from a different perspective. Among various branches of crafts, this research specifically explores introduction of digital technology to pottery and challenges the limitations that the conventional methods have, by eliminating the hardware restrictions and lowering the barriers. The outcome offers not only transcendent possibilities of creation to craftspeople and artists but also unprecedented accessibility and apprehensible process to the public. Technically, Liquid Deposition Modelling (LDM) building upon material optimisation and tool redesign was employed in conjunction with digital design process. In addition, functional additives were trialled to incorporate multilevel translucency and electrical conductivity into the new types of ceramic objects.</p>

Liquid deposition modification of nano-ZSM-5 zeolite and catalytic performance in aromatization of Hexene-1

The Olefin aromatization is an important method for the upgrade of catalytic cracking (FCC) gasoline and production of fuel oil with high octane number. The nano-ZSM-5 zeolite was synthesized via a seed-induced method, a series of modified nano-ZSM-5 zeolite samples with different Ga deposition amount were prepared by Ga liquid deposition method. The XRD, N2 physical adsorption, SEM, TEM, XPS, H2-TPR and Py-IR measurements were used to characterize the morphology, textural properties and acidity of the modified ZSM-5 zeolites. The catalytic performance of the Hexene-1 aromatization was evaluated on a fixed-bed microreactor. The effects of Ga modification on the physicochemical and catalytic performance of nano-ZSM-5 zeolites were investigated. The Ga species in the modified nano-ZSM-5 zeolites mainly exist as the form of Ga2O3 and GaO+, which provide strong Lewis acid sites. The aromatics selectivity over Ga modified nano-ZSM-5 zeolite in the Hexene-1 aromatization was significantly increased, which could be attributed to the improvement of the dehydrogenation activity. The selectivity for aromatics over the Ga4.2/NZ5 catalyst with suitable Ga deposition amount reached 55.4%.

Facile growth of aluminum oxide thin film by chemical liquid deposition and its application in devices

Uniform and continuous Al2O3 thin films were prepared by the chemical liquid deposition (CLD) method. The breakdown field strength of the amorphous CLD-Al2O3 film is 1.74 MV/cm, making it could be used as a candidate dielectric film for electronic devices. It was further proposed to use the CLD-Al2O3 film as an electron blocking layer in a triboelectric nanogenerator (TENG) for output performances enhancement. Output voltages and currents of about 200 V and 9 µA were obtained, respectively, which were 2.6 times and 3 times, respectively, higher than TENG device without an Al2O3. A colloidal condensation-based procedure controlled by adjusting the pH value of the solution was proposed to be the mechanism of CLD, which was confirmed by the Tyndall effect observed in the growth liquid. The results indicated that the CLD could serve as a low-cost, room temperature, nontoxic and facile new method for the growth of functional thin films for semiconductor device applications.

Effects of Steaming and SiO2 Surface Passivation on SSZ-13 Zeolites in the Ethylene to Propylene Reaction

SSZ-13 zeolite was modified by two kinds of post-treatment methods such as steaming and SiO2 surface passivation (silylation) for ETP catalyst with high activity. The former steaming treatment was conducted in the range of 400–700 °C, whereas the latter surfaces passivation was applied to a chemical liquid deposition (CLD) technique that uses various silylation agents such as tetramethylorthosilicate (TMOS), tetraethylorthosilicate (TEOS), and tetrabuthylorthosilicate (TBOS). Catalysts were characterized by powder-XRD, ICP, Ar-phsisorption, solid-state 27Al MAS NMR, and NH3-TPD, and their activities were tested in fixed bed reaction system. Regarding the effects of steaming temperature, the results show that a relatively higher selectivity is observed in SSZ-13 catalysts treated at proper steaming temperatures such as 450 and 500 °C compared to parent and other steam treated catalysts. For optimum surface passivation treatments for ETP reactions, one-step surface passivation using TEOS agents among various passivation agents led to enhanced propylene selectivity to 80% when compared with parent and other silylated SSZ-13 catalysts. However, a sequential passivation treatment with a TEOS agent was not highly affected by the reaction activity.

Cellulose-Based Polymers in Additive Manufacturing

The materials for additive manufacturing (AM) technology have grown substantially over the last few years to fulfill industrial needs. Despite that, the use of bio-based composites for improved mechanical properties and biodegradation is still not fully explored. This limits the universal expansion of AM-fabricated products due to the incompatibility of the products made from petroleum-derived resources. The development of naturally-derived polymers for AM materials is promising with the increasing number of studies in recent years owing to their biodegradation and biocompatibility. Cellulose is the most abundant biopolymer that possesses many favorable properties to be incorporated into AM materials, which have been continuously focused on in recent years. This critical review discusses the development of AM technologies and materials, cellulose-based polymers, cellulose-based three-dimensional (3D) printing filaments, liquid deposition modeling of cellulose, and four-dimensional (4D) printing of cellulose-based materials. Cellulose-based AM material applications and the limitations with future developments are also reviewed.

Extending Cellulose-Based Polymers Application in Additive Manufacturing Technology: A Review of Recent Approaches

The materials for additive manufacturing (AM) technology have grown substantially over the last few years to fulfill industrial needs. Despite that, the use of bio-based composites for improved mechanical properties and biodegradation is still not fully explored. This limits the universal expansion of AM-fabricated products due to the incompatibility of the products made from petroleum-derived resources. The development of naturally-derived polymers for AM materials is promising with the increasing number of studies in recent years owing to their biodegradation and biocompatibility. Cellulose is the most abundant biopolymer that possesses many favorable properties to be incorporated into AM materials, which have been continuously focused on in recent years. This critical review discusses the development of AM technologies and materials, cellulose-based polymers, cellulose-based three-dimensional (3D) printing filaments, liquid deposition modeling of cellulose, and four-dimensional (4D) printing of cellulose-based materials. Cellulose-based AM material applications and the limitations with future developments are also reviewed.