Influence of hydroxypropyl methylcellulose and silica fume on stability, rheological properties, and printability of 3D printing foam concrete

Rapidly growing 3D printing of hydrogels requires network materials which combine enhanced mechanical properties and printability. One of the most promising approaches to strengthen the hydrogels consists of the incorporation of inorganic fillers. In this paper, the rheological properties important for 3D printability were studied for nanocomposite hydrogels based on a rigid network of percolating halloysite nanotubes embedded in a soft alginate network cross-linked by calcium ions. Particular attention was paid to the effect of polymer cross-linking on these properties. It was revealed that the system possessed a pronounced shear-thinning behavior accompanied by a viscosity drop of 4–5 orders of magnitude. The polymer cross-links enhanced the shear-thinning properties and accelerated the viscosity recovery at rest so that the system could regain 96% of viscosity in only 18 s. Increasing the cross-linking of the soft network also enhanced the storage modulus of the nanocomposite system by up to 2 kPa. Through SAXS data, it was shown that at cross-linking, the junction zones consisting of fragments of two laterally aligned polymer chains were formed, which should have provided additional strength to the hydrogel. At the same time, the cross-linking of the soft network only slightly affected the yield stress, which seemed to be mainly determined by the rigid percolation network of nanotubes and reached 327 Pa. These properties make the alginate/halloysite hydrogels very promising for 3D printing, in particular, for biomedical purposes taking into account the natural origin, low toxicity, and good biocompatibility of both components.

Download Full-text

Understanding the structure and rheological properties of potato starch induced by hot-extrusion 3D printing

Food Hydrocolloids ◽

10.1016/j.foodhyd.2020.105812 ◽

2020 ◽

Vol 105 ◽

pp. 105812 ◽

Cited By ~ 6

Author(s):

Zipeng Liu ◽

Huan Chen ◽

Bo Zheng ◽

Fengwei Xie ◽

Ling Chen

Keyword(s):

3D Printing ◽

Rheological Properties ◽

Potato Starch ◽

Hot Extrusion

Download Full-text

Optimization of the Formulation and Properties of 3D-Printed Complex Egg White Protein Objects

Foods ◽

10.3390/foods9020164 ◽

2020 ◽

Vol 9 (2) ◽

pp. 164 ◽

Cited By ~ 5

Author(s):

Lili Liu ◽

Xiaopan Yang ◽

Bhesh Bhandari ◽

Yuanyuan Meng ◽

Sangeeta Prakash

Keyword(s):

3D Printing ◽

Rheological Properties ◽

Sensory Evaluation ◽

Egg White ◽

Egg White Protein ◽

Evaluation Score ◽

Optimum Formulation ◽

Printing System ◽

3D Printed ◽

New Formulation

The 3D printing of foods is an emerging technique for producing unique and complex food items. This study presents the optimization of a new formulation for 3D printing foods on the basis of a complex system, which contains egg white protein (EWP), gelatin, cornstarch, and sucrose. The effects of different formulations on the rheological properties and the microstructure of the printing system were investigated. The formulation was optimized through response surface methodology, and a central composite design was adopted. The optimum formulation of the 3D mixture printing system was made of gelatin (14.27 g), cornstarch (19.72 g), sucrose (8.02 g), and EWP (12.98 g) in 250 mL of total deionized water with a maximum sensory evaluation score of 34.47 ± 1.02 and a viscosity of 1.374 ± 0.015 Pa·s. Results showed that the viscosity of the formulation correlated with the sensory evaluation score. The rheological properties and tribological behavior of the optimum formulation significantly differed from those of other formulations. A viscosity of 1.374 Pa·s supported the timely flow out of the printing material from the nozzle assisting 3D printability. Thus, 3D printing based on the egg white protein mixture system is a promising method for producing complex-shaped food objects.

Download Full-text

Colloidal Materials for 3D Printing

Annual Review of Chemical and Biomolecular Engineering ◽

10.1146/annurev-chembioeng-060718-030133 ◽

2019 ◽

Vol 10 (1) ◽

pp. 17-42 ◽

Cited By ~ 8

Author(s):

Cheng Zhu ◽

Andrew J. Pascall ◽

Nikola Dudukovic ◽

Marcus A. Worsley ◽

Joshua D. Kuntz ◽

...

Keyword(s):

3D Printing ◽

Rheological Properties ◽

State Of The Art ◽

Functional Materials ◽

Carbonaceous Materials ◽

Colloidal Processing ◽

Processing Strategies ◽

Multiple Length Scales ◽

Printing Techniques ◽

Colloidal Materials

In recent years, 3D printing has led to a disruptive manufacturing revolution that allows complex architected materials and structures to be created by directly joining sequential layers into designed 3D components. However, customized feedstocks for specific 3D printing techniques and applications are limited or nonexistent, which greatly impedes the production of desired structural or functional materials. Colloids, with their stable biphasic nature, have tremendous potential to satisfy the requirements of various 3D printing methods owing to their tunable electrical, optical, mechanical, and rheological properties. This enables materials delivery and assembly across the multiple length scales required for multifunctionality. Here, a state-of-the-art review on advanced colloidal processing strategies for 3D printing of organic, ceramic, metallic, and carbonaceous materials is provided. It is believed that the concomitant innovations in colloid design and 3D printing will provide numerous possibilities for the fabrication of new constructs unobtainable using traditional methods, which will significantly broaden their applications.

Download Full-text

3D printing of extended-release tablets of theophylline using hydroxypropyl methylcellulose (HPMC) hydrogels

International Journal of Pharmaceutics ◽

10.1016/j.ijpharm.2020.119983 ◽

2020 ◽

Vol 591 ◽

pp. 119983

Author(s):

Yiliang Cheng ◽

Hantang Qin ◽

Nuria C. Acevedo ◽

Xuepeng Jiang ◽

Xiaolei Shi

Keyword(s):

3D Printing ◽

Extended Release ◽

Hydroxypropyl Methylcellulose

Download Full-text

Predicting Pumpability and Shootability of Crushed Aggregate Wet-Mix Shotcrete Based on Rheological Properties

Advances in Materials Science and Engineering ◽

10.1155/2016/9838213 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Kyong-Ku Yun ◽

Pangil Choi ◽

Jung Heum Yeon

Keyword(s):

Fly Ash ◽

Rheological Properties ◽

Silica Fume ◽

Steel Fiber ◽

Wide Spectrum ◽

Granulated Blast Furnace Slag ◽

Compliance Testing ◽

Testing Data ◽

Crushed Aggregate ◽

Pump Pressure

This study aims to estimate the pumpability and shootability of wet-mix shotcrete (WMS) made with crushed aggregates and various admixtures such as silica fume, fly ash, ground granulated blast furnace slag (GGBFS), metakaolin, and steel fiber based on rheological properties. The IBB rheometer was employed as an apparatus to measure the rheological properties of freshly mixed shotcrete such as flow resistance and torque viscosity. Results have shown that the use of silica fume and metakaolin led to satisfactory pumpability, whereas mixtures with fly ash and steel fiber failed to meet the pumping criteria at normal pump pressure. The build-up thickness, an indicator to represent shotcrete shootability, was predicted to vary between 68 and 218 mm, demonstrating that the use of admixtures resulted in a wide spectrum of shootability. In particular, the use of metakaolin was found to substantially increase the predicted build-up thickness only with a small replacement. The findings of this study are expected to be used as an easy-to-use guideline for estimating pumpability and shootability of WMS when no compliance testing data is available.

Download Full-text

Hydrogel Scaffold Fabricated by 3D Printing & Ultrasonic Spraying

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1027.336 ◽

2014 ◽

Vol 1027 ◽

pp. 336-339

Author(s):

Yu Li ◽

Ping Yan Bian

Keyword(s):

3D Printing ◽

Ambient Temperature ◽

Rheological Properties ◽

Biological Material ◽

Crosslinking Agent ◽

Hydrogel Scaffold ◽

Novel Strategy

This paper presents a novel strategy for fabricating hydrogel scaffold at ambient temperature by 3D printing supplemented with an ultrasonic spraying which involves crosslink reaction. The contradictory between the rheological properties and solidification of natural biological material for machinability and formability respectively at ambient temperature was solved. The gelled fraction and porosity were measured respectively to study the influence of crosslinking agent. The results showed that the two subjects appear a parabolic trend with the concentration of CaCl2 from 2% to 4%, but the tolerance of aperture decreases monotone.

Download Full-text