Why are alkylene carbonates like ethylene carbonate and propylene carbonate good for industrial cleaning?

Alkylene carbonates like ethylene carbonate (EC) and propylene carbonate (PC) are chosen for cleaning due to their polarity, high boiling points, low toxicity, and biodegradability. Propylene carbonate is also used as a green solvent in agriculture, medications, and cosmetics. Both EC and PC are used as photoresist stripping agents because they mix well with water and organic solvents, which is important in semiconductor manufacturing for removing photoresist.

What are Pluronic surfactants, and how do their structures contribute to their cleaning properties?

Pluronic surfactants are triblock copolymers made of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO). Their structure allows them to act as detergents, emulsifiers, dispersants, and lubricants. The balance between the PEO and PPO segments is crucial; PEO is solvophilic (attracted to the solvent), while PPO is solvophobic (repelled by the solvent). This balance determines how they interact with surfaces and prevent readsorption.

How does the solvophilic and solvophobic nature of PEO and PPO impact the performance of Pluronic surfactants in EC/PC solvents?

The solvophilic nature of poly(ethylene oxide) (PEO) means it is attracted to the EC/PC mixture, while the solvophobic nature of poly(propylene oxide) (PPO) means it is repelled. In an EC/PC solvent mixture, this contrast is key to how Pluronic surfactants prevent photoresist from being redeposited. The PEO segments anchor the surfactant to the solvent, while the PPO segments interact with the surface, creating a barrier.

How do force curve measurements support the understanding of how Pluronic surfactants prevent photoresist readsorption?

Force curve measurements show that Pluronic surfactants create repulsive forces, preventing photoresist from redepositing on surfaces. For example, the Pluronic surfactant F-68 shows a continuous increase in repulsive interaction as separation decreases, indicating it forms a polymer brush on the silica surface. The Milner-Witten-Cates (MWC) theory helps explain this behavior, further confirming that F-68 forms a polymer brush structure.

What future research is needed to improve the use of Pluronic surfactants in surface cleaning?

Future research should focus on how stable Pluronic surfactant layers are over time and under different conditions. This includes testing how well they perform in various cleaning scenarios and how they hold up against different types of contamination. Understanding these factors will help in the wider use of Pluronic surfactants in advanced cleaning processes, improving efficiency and reducing environmental impact.

Pluronic surfactants forming a protective layer on silica, preventing photoresist readsorption

The Secret to Spotless Surfaces: How Pluronic Surfactants Are Revolutionizing Cleaning

Lena Voss in Tech & Innovation September 2025 • 4 min read.

"Unveiling the Science Behind Anti-Readsorption: A Deep Dive into Pluronic Surfactants in Alkylene Carbonates on Silica"

In the quest for impeccable cleanliness across various industries, alkylene carbonates (cyclic acid esters) have emerged as commercially attractive polar aprotic solvents. Ethylene carbonate (EC) and propylene carbonate (PC) exemplify these solvents, celebrated for their polarity, high boiling points, low toxicity, and biodegradability. These attributes make them indispensable in cleaning, degreasing, paint stripping, and textile dyeing.

More recently, propylene carbonate has found a niche as a green solvent in agriculture, medications, and cosmetics, underscoring its versatility and environmental compatibility. Both EC and PC are invaluable as photoresist stripping agents, owing to their remarkable miscibility in water and organic solvents. This is particularly vital in semiconductor manufacturing, where they remove photoresist from substrates after photolithography. An EC/PC mixture is favored for being less corrosive and toxic compared to amine-type agents.

The challenge, however, lies in the readsorption of stripped resist onto the surface during water rinsing. To counteract this, amphiphilic materials are introduced, and among these, Pluronic surfactants stand out. As triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), Pluronics are used extensively in detergents, emulsions, dispersions, and lubrication. Their interfacial properties are finely tunable by adjusting the PEO/PPO ratio and chain length.

Understanding Pluronic Surfactants: Structure, Function, and Adsorption

Pluronic surfactants forming a protective layer on silica, preventing photoresist readsorption

Pluronic surfactants have been researched for their adsorption behavior on hydrophilic and hydrophobic surfaces in water. Self-assembled monolayers (SAMs) with Pluronics have even been shown to prevent protein adsorption. Studies in ionic liquids (ILs) have revealed that Pluronics can form brush structures, impacting surface interactions.

In a mixed EC/PC solvent, the behavior of Pluronic surfactants hinges on the interplay between the PEO and PPO blocks. The EC/PC mixture is a good solvent for the PEO block and a poor solvent for the PPO block. This contrast leverages the high dipole moment and dielectric constant of the EC/PC mixture. This dynamic is similar to Pluronic systems in water and EAN, despite differences in solvent properties.

PEO as a Solvophilic Group: The poly(ethylene oxide) chain is drawn to the solvent.
PPO as a Solvophobic Group: The poly(propylene oxide) chain is repelled by the solvent.
Force Curve Measurements: These measurements reveal repulsive forces from an apparent separation of 20–30 nm for Pluronics at 10 mmol dm⁻³.
Longest PEO Chain Impact: The most solvophilic Pluronic surfactant, F-68, exhibits a continuously increasing repulsive interaction as separation decreases.
MWC Theory Application: The Milner-Witten-Cates theory effectively describes the repulsive force curve data of F-68, suggesting it forms a polymer brush on the silica surface.
Stretching Forces: Retracting force curve measurements detect stretching forces across Pluronic systems. These forces are more frequent in L-62 but have shorter pull-off distances compared to F-68.

This study characterizes the adsorption of Pluronic surfactants on silica in a mixed EC/PC solvent, evaluating the impact of PEO chain length on adsorption. The ultimate goal is to better understand the anti-readsorption properties of Pluronics, offering insights to prevent photoresist redeposition on solid substrates.

The Future of Surface Cleaning: Implications and Applications

This research underscores the potential of Pluronic surfactants in preventing photoresist readsorption, offering a pathway to cleaner industrial processes. By understanding the interactions between Pluronic surfactants, solvents, and surfaces, we can tailor solutions for diverse cleaning needs, driving efficiency and reducing environmental impact. Future studies should explore the long-term stability and performance of these surfactant layers under varying conditions, paving the way for broader adoption in advanced cleaning applications.