Research & Development World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE

New surface treatment stops scale buildup

By R&D Editors | January 23, 2014

A comparison between an untreated smooth surface (left) and lubricant-impregnated surface (right), after having gypsum-rich water boiled away from it in the laboratory. The treated surface shows significantly less scale deposition. Image courtesy of the researchersYou’ve probably seen it in your kitchen cookware, or inside old plumbing pipes: scaly deposits left over time by hard, mineral-laden water. It happens not only in pipes and cooking pots in the home, but also in pipelines and valves that deliver oil and gas, and pipes that carry cooling water inside power plants.

Scale, as these deposits are known, causes inefficiencies, downtime and maintenance issues. In the oil and gas industry, scale has sometimes led to the complete shutdown, at least temporarily, of operating wells. So addressing this problem could have a big payoff.

Now a team of researchers at Massachusetts Institute of Technology (MIT) has come up with a potential solution to this huge but little-recognized problem. A new kind of surface treatment—involving nanoscale texturing of the surface, which is then coated with a lubricating liquid—can reduce the rate of scale formation at least tenfold, they have found. The findings are reported in Advanced Materials Interfaces written by graduate student Srinivas Subramanyam, postdoctoral researcher Gisele Azimi and Kripa Varanasi, the doherty assoc. prof. of ocean utilization in MIT’s Dept. of Mechanical Engineering.

“You can see [scale] pretty much everywhere,” Varanasi says. In the home, these deposits are mostly an annoyance, but in industry they can cause “lost productivity, and the ways of removing [them] can be environmentally harmful,” typically involving the use of harsh chemicals. And in power plants and desalination plants, scale can cause significant efficiency losses, because it acts as a thermal barrier that impairs cooling or condensing in heat exchangers.

The problem arises because water often contains large amounts of dissolved salts and minerals. The ability of water to dissolve these materials depends on solubility, so if the water cools or evaporates, the solution may become supersaturated: It contains more of the dissolved material than it can accommodate, so some begins to precipitate out. It’s the same principle that causes fogging on a cold glass when warm, moist air cools suddenly as it meets a cooler surface.

For the most part, engineers have dealt with the problem by overdesigning systems, Varanasi says: Using pipes that are much larger than needed, for example, in anticipation of the partial blockages that scaling will cause, or a larger surface area, in the case of heat exchangers.

The problem is far from new, Subramanyam points out: “Cooking pots from ancient times have this buildup,” he says. “We don’t have good solutions yet.”

Though it remains to be proven on an industrial scale, the new approach developed by the MIT team could make a significant difference in the rate of scale formation, and in many situations may prevent it altogether.

Their approach sounds deceptively simple: effective nanotexturing of the surface and filling the resulting textures with a lubricant. The texturing depends mostly on the scale of the bumps and grooves produced; the precise shapes don’t seem to matter. So a variety of techniques can be used to create that texture—including applying a textured coating to the surface, or chemically etching it in place.

The researchers also describe a process for selecting appropriate lubricants that can not only increase the energy barrier for scale formation, but also spread on the textured solid, making the surface “smooth” and reducing the nucleation sites available for scale formation.

Previous attempts to prevent or reduce scale formation have typically involved adding a coating (such as Teflon) to a surface to prevent minerals from bonding to it. The problem with that approach, Varanasi explains, is that these coatings can wear out, just as the coating on a nonstick frying pan often degrades with use. And if there’s even a pinprick of a hole in that coating, he says, that provides a place for scale to begin forming.

With the new method, once the nanotexture has been created on the surface, oil or another lubricating liquid is applied to that surface. The tiny nanoscale grooves capture this liquid, holding it firmly in place through capillary action, Varanasi says. Unlike a solid nonstick coating, the liquid can flow to fill any gaps, spread on the surface textures, and can be replenished continually if some is washed away. “Even if there’s mechanical damage, the lubricant can return to that surface,” Subramanyam says. “It can maintain its smoothness for an extended period of time.”

Because this lubricant layer is vanishingly thin, protecting a surface for decades would require only a tiny amount of lubricant. Reservoirs built into a section of pipe could supply lubrication for the lifetime of the equipment, Varanasi says. In the case of oil pipelines, “the lubricant is already there,” and oil captured by the surface texturing could protect the pipe surfaces.

After further laboratory testing to determine the best lubricants and texturing methods for particular applications, this system could be ready for commercial applications in as little as three years, the researchers say.

Source: Massachusetts Institute of Technology

Related Articles Read More >

KIST carbon nanotube supercapacitor holds capacity after 100,000 cycles
A new wave of metalworking lets semiconductor crystals bend and stretch
LLNL deposits quantum dots on corrugated IR chips in a single step
KATRIN inauguration photo form 2018
Neutrinos pinned below 0.45 eV; KATRIN halves the particle’s mass ceiling
rd newsletter
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, trends, and strategies in Research & Development.
RD 25 Power Index

R&D World Digital Issues

Fall 2024 issue

Browse the most current issue of R&D World and back issues in an easy to use high quality format. Clip, share and download with the leading R&D magazine today.

Research & Development World
  • Subscribe to R&D World Magazine
  • Enews Sign Up
  • Contact Us
  • About Us
  • Drug Discovery & Development
  • Pharmaceutical Processing
  • Global Funding Forecast

Copyright © 2025 WTWH Media LLC. All Rights Reserved. The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media
Privacy Policy | Advertising | About Us

Search R&D World

  • R&D World Home
  • Topics
    • Aerospace
    • Automotive
    • Biotech
    • Careers
    • Chemistry
    • Environment
    • Energy
    • Life Science
    • Material Science
    • R&D Management
    • Physics
  • Technology
    • 3D Printing
    • A.I./Robotics
    • Software
    • Battery Technology
    • Controlled Environments
      • Cleanrooms
      • Graphene
      • Lasers
      • Regulations/Standards
      • Sensors
    • Imaging
    • Nanotechnology
    • Scientific Computing
      • Big Data
      • HPC/Supercomputing
      • Informatics
      • Security
    • Semiconductors
  • R&D Market Pulse
  • R&D 100
    • Call for Nominations: The 2025 R&D 100 Awards
    • R&D 100 Awards Event
    • R&D 100 Submissions
    • Winner Archive
    • Explore the 2024 R&D 100 award winners and finalists
  • Resources
    • Research Reports
    • Digital Issues
    • R&D Index
    • Subscribe
    • Video
    • Webinars
  • Global Funding Forecast
  • Top Labs
  • Advertise
  • SUBSCRIBE