Process for protecting porous structure using nanoparticles driven by electrokinetic pulse

Abstract

A process for protecting a porous structure includes providing a treatment fluid including nanoparticles including a sealant material coated with a metal ion to a face of the porous structure, and applying a sequence of DC voltage pulses to the porous structure in a position so as to drive the nanoparticles on the face of the porous structure into the porous structure. The metal ion coating of the nanoparticle separates from the sealant material within the porous structure to close pores within the porous structure.

1 . A process for protecting a porous structure comprising:
 providing a treatment fluid including nanoparticles comprising a sealant material coated with a metal ion to a face of the porous structure;   applying a sequence of DC voltage pulses to the porous structure in a position so as to drive the nanoparticles on the face of the porous structure into the porous structure;   wherein the metal ion coating of the nanoparticle separates from the sealant material within the porous structure, the sealant material being for use in closing pores within the porous structure.   
   
   
       2 . A process as set forth in  claim 1  wherein applying a sequence of DC voltage pulses comprises applying pulses having a duration of less than about 1000 ms. 
   
   
       3 . A process as set forth in  claim 2  wherein the pulse duration is about 100 ms. 
   
   
       4 . A process as set forth in  claim 2  wherein the pulses are separated from each other by an time approximately equal to the duration of the pulse. 
   
   
       5 . A process as set forth in  claim 1  wherein applying a sequence of DC pulses comprises periodically changing the polarity of the DC pulse. 
   
   
       6 . A process as set forth in  claim 5  wherein periodically changing the polarity comprises changing the polarity of no more than about 1 out of every 5 DC voltage pulses applied to the porous structure. 
   
   
       7 . A process as set forth in  claim 5  wherein periodically changing the polarity comprises changing the polarity of no more than about 1 out of every 10 DC voltage pulses applied to the porous structure. 
   
   
       8 . A process as set forth in  claim 1  wherein providing a treatment fluid comprises providing nanoparticles having a silicate sealant material. 
   
   
       9 . A process as set forth in  claim 8  wherein providing a treatment fluid comprises providing nanoparticles having a lithium ion coating. 
   
   
       10 . A process as set forth in  claim 9  wherein providing a treatment fluid comprises providing nanoparticles having a latex sealant material. 
   
   
       11 . A process as set forth in  claim 10  wherein providing a treatment fluid comprises providing nanoparticles having a zinc ion coating. 
   
   
       12 . A process as set forth in  claim 10  further comprising, subsequent to said step of applying a sequence of DC pulses of applying electroosmosis to the porous structure to dehydrate the latex and initiate self assembly of the latex to block pores within the porous structure. 
   
   
       13 . A process for moving nanoparticles into a concrete structure having capillary pores to treat the concrete structure, the process comprising:
 delivering a treatment fluid mixture of nanoparticles within a carrier liquid to an anode, the nanoparticles comprising silica colloidal nanoparticles coated with lithium;   applying a sequence of DC voltage pulses to the anode to induce movement of the treatment fluid mixture from the anode toward a cathode spaced remotely from the anode so that the treatment fluid mixture flows into the capillary pores of the concrete structure,   wherein lithium ions of the nanoparticles separate from the silica colloidal nanoparticles in the capillary pores of the concrete structure,   wherein the separated lithium ions prevent or mitigate alkali-silica reactions (ASR) in the concrete structure and the silica colloidal nanoparticles react with free calcium hydroxides in the concrete structure to create calcium silicate hydrate (CSH).   
   
   
       14 . A process for moving nanoparticles into a concrete structure having capillary pores to treat the concrete structure, the process comprising:
 delivering a treatment fluid mixture of nanoparticles within a carrier liquid to an anode, the nanoparticles comprising a polymer coated with zinc;   applying a first sequence of DC voltage pulses to the anode to induce movement of the treatment fluid mixture from the anode toward a cathode spaced remotely from the anode so that the treatment fluid mixture flows into the capillary pores of the concrete structure,   applying a second sequence of DC voltage pulses to drive the carrier liquid out of the concrete structure leaving the polymer coated with zinc in the capillary pores, whereby the polymer expands into pores within the concrete structure.