3D Printing with Light

Pu Xiao, Jing Zhang, Pu Xiao, Jing Zhang

• Publisher: De Gruyter
• Year: 2021
• eBook ISBN: 9783110569841
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Physical & Theoretical Chemistry

The book introduces fundamentals of 3D printing with light, photoinitiating system for 3D printing as well as resins. Plenty of applications, trends and prospects are also discussed, which make the book an essential reference for both scientists and industrial engineers in the research fields of photochemistry, polymer chemistry, rapid prototyping and photopolymerization.

Chapter 1 Novel photoinitiating systems for 3D printing

D. Zhu

Research School of Chemistry, Australian National University, Canberra, Australia

J. Zhang

Department of Chemical Engineering, Monash University, Clayton, Victoria, Australia

J. Lalevée

Université de Haute-Alsace, CNRS, Institut de Science des Matériaux de Mulhouse (IS2M), Mulhouse, France

P. Xiao

Research School of Chemistry, Australian National University, Canberra, Australia

The photosensitive formula for one-photon and two-photon 3D printing consists of photoinitiating system (PIS) and photocurable monomers/oligomers [1, 2]. PIS refers to the components group that is irradiated directly by light and produces active initiating species (free radicals and/or cations) [1, 2]. In more detail, photoinitiator (PI) is excited by photons, then either homocleaved into free radicals or reacted with additives via oxidation and energy transfer to generate radicals and/or cations for polymerization initiation [1, 3]. Therefore, the properties of PIs in terms of functional group conversion (FC), rate of polymerization (R_P,max), color, transparency and photobleaching affect toughness of 3D printed objects and 3D printer parameters such as printing layer thickness and printing duration for each layer [2].

Commercial photoinitiators, 2,4,6-trimethylbenzoyldiphenyl phosphine oxide(TPO), phenylbis(2,4,6-trimethyl-benzoyl)phosphine oxide (BAPO), (1-hydroxycyclohexyl)(phenyl)methanone (Irgacure 184), 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one (Irgacure 369), etc., are efficient and commonly used in PISs for 3D printing [4]. However, 3D printing technology has been applied to various fields such as tissue engineering, oral drug production, electrically conductive constructs, etc. [5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]. Commercial PISs have obvious drawbacks such as UV initiation, toxicity and low efficiency in further advanced use of 3D printing technology. To improve the efficiency of PISs, and to fit low intensity commercial 3D printer projector in order to meet the standards in some special fields (e.g., medicine, scaffolds, etc.), additional requirements (e.g., non-toxic, visible-light initiable and highly efficient) have to be considered. Tons of efficiently designed type I and type II photoinitiators for 3D printing have been reported (e.g., metal complexes, flavone derivatives and naphthalimide derivatives) [24, 25, 26]. In this chapter, an overview of the newly developed PISs of centimeter-scale and nanoscale 3D printing are discussed. Guidance on how to evaluate if a PI or a PIS is suitable for 3D printing is provided as well.

1.1 Novel photoinitiating systems in 3D printing

1.1.1 Naturally originated and derived photoinitiators

Due to abundant brightly colored substances (i.e., dyes), nature is a large provider of potential PIs that are sensitive to visible light LEDs exposure. For instance, curcumin, a bright yellow turmeric extract, has been observed to be a blue-light-sensitive PI [27]; riboflavin, also called vitamin B, is another well-investigated natural PI under blue lights [28, 29]. Several naturally originated and derived compounds have been reported to be efficient PIs [30, 31, 32, 33, 34, 35, 36]. Flavone and coumarin derivatives are presented in this subsection to introduce their properties and abilities for 3D printing.

1.1.1.1 Flavone-derivative-based photoinitiating systems

Flavone derivatives reported as antioxidants [37] have been discovered to be a new series of blue-light-sensitive PIs in recent years [24, 38]. A general mechanism of photoinitiation process was proposed [24, 38]. Specifically, flavones are excited to singlet or triplet state by photons (r1) and then reacted with NPG or...

Table of contents

• Title Page
• Copyright
• Contents
• Chapter 1 Novel photoinitiating systems for 3D printing
• Chapter 2 New free radical and cationic photoinitiators for two-photon 3D printing
• Chapter 3 Functional dyes in light-induced 3D printing
• Chapter 4 Resin design in stereolithography 3D printing for microfluidic applications
• Chapter 5 3D printing of biomaterials
• Chapter 6 Photopolymerization and its application in 3D printing of customized objects
• Chapter 7 Dual wavelength systems in 3D printing
• Chapter 8 Functional 3D nanoprinting via femtosecond laser nonlinear lithography
• Chapter 9 3D printing mediated by photoRAFT polymerization process
• Chapter 10 Main challenges in 3D printing: Printing speed and biomedical applications
• Index